dslinux/user/pixil/packages/flash/flash/Jpeg Makefile README ckconfig.c jcomapi.c jconfig.h jdapimin.c jdapistd.c jdatadst.c jdatasrc.c jdcoefct.c jdcolor.c jdct.h jddctmgr.c jdhuff.c jdhuff.h jdinput.c jdmainct.c jdmarker.c jdmaster.c jdmerge.c jdphuff.c jdpostct.c jdsample.c jdtrans.c jerror.c jerror.h jidctflt.c jidctfst.c jidctint.c jidctred.c jinclude.h jmemmgr.c jmemnobs.c jmemsys.h jmorecfg.h jpegint.h jpeglib.h jquant1.c jquant2.c jutils.c jversion.h
amadeus
dslinux_amadeus at user.in-berlin.de
Tue Oct 3 13:26:08 CEST 2006
Update of /cvsroot/dslinux/dslinux/user/pixil/packages/flash/flash/Jpeg
In directory antilope:/tmp/cvs-serv11916/packages/flash/flash/Jpeg
Added Files:
Makefile README ckconfig.c jcomapi.c jconfig.h jdapimin.c
jdapistd.c jdatadst.c jdatasrc.c jdcoefct.c jdcolor.c jdct.h
jddctmgr.c jdhuff.c jdhuff.h jdinput.c jdmainct.c jdmarker.c
jdmaster.c jdmerge.c jdphuff.c jdpostct.c jdsample.c jdtrans.c
jerror.c jerror.h jidctflt.c jidctfst.c jidctint.c jidctred.c
jinclude.h jmemmgr.c jmemnobs.c jmemsys.h jmorecfg.h jpegint.h
jpeglib.h jquant1.c jquant2.c jutils.c jversion.h
Log Message:
adding pristine copy of pixil to HEAD so I can branch from it
--- NEW FILE: jdtrans.c ---
/*
* jdtrans.c
*
* Copyright (C) 1995-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains library routines for transcoding decompression,
* that is, reading raw DCT coefficient arrays from an input JPEG file.
* The routines in jdapimin.c will also be needed by a transcoder.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Forward declarations */
LOCAL(void) transdecode_master_selection JPP((j_decompress_ptr cinfo));
/*
* Read the coefficient arrays from a JPEG file.
* jpeg_read_header must be completed before calling this.
*
* The entire image is read into a set of virtual coefficient-block arrays,
* one per component. The return value is a pointer to the array of
* virtual-array descriptors. These can be manipulated directly via the
* JPEG memory manager, or handed off to jpeg_write_coefficients().
* To release the memory occupied by the virtual arrays, call
* jpeg_finish_decompress() when done with the data.
*
* An alternative usage is to simply obtain access to the coefficient arrays
* during a buffered-image-mode decompression operation. This is allowed
* after any jpeg_finish_output() call. The arrays can be accessed until
* jpeg_finish_decompress() is called. (Note that any call to the library
* may reposition the arrays, so don't rely on access_virt_barray() results
* to stay valid across library calls.)
*
* Returns NULL if suspended. This case need be checked only if
* a suspending data source is used.
*/
GLOBAL(jvirt_barray_ptr *)
jpeg_read_coefficients (j_decompress_ptr cinfo)
{
if (cinfo->global_state == DSTATE_READY) {
/* First call: initialize active modules */
transdecode_master_selection(cinfo);
cinfo->global_state = DSTATE_RDCOEFS;
}
if (cinfo->global_state == DSTATE_RDCOEFS) {
/* Absorb whole file into the coef buffer */
for (;;) {
int retcode;
/* Call progress monitor hook if present */
if (cinfo->progress != NULL)
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
/* Absorb some more input */
retcode = (*cinfo->inputctl->consume_input) (cinfo);
if (retcode == JPEG_SUSPENDED)
return NULL;
if (retcode == JPEG_REACHED_EOI)
break;
/* Advance progress counter if appropriate */
if (cinfo->progress != NULL &&
(retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
/* startup underestimated number of scans; ratchet up one scan */
cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
}
}
}
/* Set state so that jpeg_finish_decompress does the right thing */
cinfo->global_state = DSTATE_STOPPING;
}
/* At this point we should be in state DSTATE_STOPPING if being used
* standalone, or in state DSTATE_BUFIMAGE if being invoked to get access
* to the coefficients during a full buffered-image-mode decompression.
*/
if ((cinfo->global_state == DSTATE_STOPPING ||
cinfo->global_state == DSTATE_BUFIMAGE) && cinfo->buffered_image) {
return cinfo->coef->coef_arrays;
}
/* Oops, improper usage */
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
return NULL; /* keep compiler happy */
}
/*
* Master selection of decompression modules for transcoding.
* This substitutes for jdmaster.c's initialization of the full decompressor.
*/
LOCAL(void)
transdecode_master_selection (j_decompress_ptr cinfo)
{
/* This is effectively a buffered-image operation. */
cinfo->buffered_image = TRUE;
/* Entropy decoding: either Huffman or arithmetic coding. */
if (cinfo->arith_code) {
ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
} else {
if (cinfo->progressive_mode) {
#ifdef D_PROGRESSIVE_SUPPORTED
jinit_phuff_decoder(cinfo);
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
} else
jinit_huff_decoder(cinfo);
}
/* Always get a full-image coefficient buffer. */
jinit_d_coef_controller(cinfo, TRUE);
/* We can now tell the memory manager to allocate virtual arrays. */
(*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
/* Initialize input side of decompressor to consume first scan. */
(*cinfo->inputctl->start_input_pass) (cinfo);
/* Initialize progress monitoring. */
if (cinfo->progress != NULL) {
int nscans;
/* Estimate number of scans to set pass_limit. */
if (cinfo->progressive_mode) {
/* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
nscans = 2 + 3 * cinfo->num_components;
} else if (cinfo->inputctl->has_multiple_scans) {
/* For a nonprogressive multiscan file, estimate 1 scan per component. */
nscans = cinfo->num_components;
} else {
nscans = 1;
}
cinfo->progress->pass_counter = 0L;
cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
cinfo->progress->completed_passes = 0;
cinfo->progress->total_passes = 1;
}
}
--- NEW FILE: jidctflt.c ---
/*
* jidctflt.c
*
* Copyright (C) 1994-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains a floating-point implementation of the
* inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
* must also perform dequantization of the input coefficients.
*
* This implementation should be more accurate than either of the integer
* IDCT implementations. However, it may not give the same results on all
* machines because of differences in roundoff behavior. Speed will depend
* on the hardware's floating point capacity.
*
* A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
* on each row (or vice versa, but it's more convenient to emit a row at
* a time). Direct algorithms are also available, but they are much more
* complex and seem not to be any faster when reduced to code.
*
* This implementation is based on Arai, Agui, and Nakajima's algorithm for
* scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
* Japanese, but the algorithm is described in the Pennebaker & Mitchell
* JPEG textbook (see REFERENCES section in file README). The following code
* is based directly on figure 4-8 in P&M.
* While an 8-point DCT cannot be done in less than 11 multiplies, it is
* possible to arrange the computation so that many of the multiplies are
* simple scalings of the final outputs. These multiplies can then be
* folded into the multiplications or divisions by the JPEG quantization
* table entries. The AA&N method leaves only 5 multiplies and 29 adds
* to be done in the DCT itself.
* The primary disadvantage of this method is that with a fixed-point
* implementation, accuracy is lost due to imprecise representation of the
* scaled quantization values. However, that problem does not arise if
* we use floating point arithmetic.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
#ifdef DCT_FLOAT_SUPPORTED
/*
* This module is specialized to the case DCTSIZE = 8.
*/
#if DCTSIZE != 8
Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
#endif
/* Dequantize a coefficient by multiplying it by the multiplier-table
* entry; produce a float result.
*/
#define DEQUANTIZE(coef,quantval) (((FAST_FLOAT) (coef)) * (quantval))
/*
* Perform dequantization and inverse DCT on one block of coefficients.
*/
GLOBAL(void)
jpeg_idct_float (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
FAST_FLOAT tmp10, tmp11, tmp12, tmp13;
FAST_FLOAT z5, z10, z11, z12, z13;
JCOEFPTR inptr;
FLOAT_MULT_TYPE * quantptr;
FAST_FLOAT * wsptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
FAST_FLOAT workspace[DCTSIZE2]; /* buffers data between passes */
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array. */
inptr = coef_block;
quantptr = (FLOAT_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; ctr--) {
/* Due to quantization, we will usually find that many of the input
* coefficients are zero, especially the AC terms. We can exploit this
* by short-circuiting the IDCT calculation for any column in which all
* the AC terms are zero. In that case each output is equal to the
* DC coefficient (with scale factor as needed).
* With typical images and quantization tables, half or more of the
* column DCT calculations can be simplified this way.
*/
if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 &&
inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 &&
inptr[DCTSIZE*7] == 0) {
/* AC terms all zero */
FAST_FLOAT dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
wsptr[DCTSIZE*0] = dcval;
wsptr[DCTSIZE*1] = dcval;
wsptr[DCTSIZE*2] = dcval;
wsptr[DCTSIZE*3] = dcval;
wsptr[DCTSIZE*4] = dcval;
wsptr[DCTSIZE*5] = dcval;
wsptr[DCTSIZE*6] = dcval;
wsptr[DCTSIZE*7] = dcval;
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
continue;
}
/* Even part */
tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
tmp10 = tmp0 + tmp2; /* phase 3 */
tmp11 = tmp0 - tmp2;
tmp13 = tmp1 + tmp3; /* phases 5-3 */
tmp12 = (tmp1 - tmp3) * ((FAST_FLOAT) 1.414213562) - tmp13; /* 2*c4 */
tmp0 = tmp10 + tmp13; /* phase 2 */
tmp3 = tmp10 - tmp13;
tmp1 = tmp11 + tmp12;
tmp2 = tmp11 - tmp12;
/* Odd part */
tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
z13 = tmp6 + tmp5; /* phase 6 */
z10 = tmp6 - tmp5;
z11 = tmp4 + tmp7;
z12 = tmp4 - tmp7;
tmp7 = z11 + z13; /* phase 5 */
tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562); /* 2*c4 */
z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */
tmp10 = ((FAST_FLOAT) 1.082392200) * z12 - z5; /* 2*(c2-c6) */
tmp12 = ((FAST_FLOAT) -2.613125930) * z10 + z5; /* -2*(c2+c6) */
tmp6 = tmp12 - tmp7; /* phase 2 */
tmp5 = tmp11 - tmp6;
tmp4 = tmp10 + tmp5;
wsptr[DCTSIZE*0] = tmp0 + tmp7;
wsptr[DCTSIZE*7] = tmp0 - tmp7;
wsptr[DCTSIZE*1] = tmp1 + tmp6;
wsptr[DCTSIZE*6] = tmp1 - tmp6;
wsptr[DCTSIZE*2] = tmp2 + tmp5;
wsptr[DCTSIZE*5] = tmp2 - tmp5;
wsptr[DCTSIZE*4] = tmp3 + tmp4;
wsptr[DCTSIZE*3] = tmp3 - tmp4;
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
}
/* Pass 2: process rows from work array, store into output array. */
/* Note that we must descale the results by a factor of 8 == 2**3. */
wsptr = workspace;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Rows of zeroes can be exploited in the same way as we did with columns.
* However, the column calculation has created many nonzero AC terms, so
* the simplification applies less often (typically 5% to 10% of the time).
* And testing floats for zero is relatively expensive, so we don't bother.
*/
/* Even part */
tmp10 = wsptr[0] + wsptr[4];
tmp11 = wsptr[0] - wsptr[4];
tmp13 = wsptr[2] + wsptr[6];
tmp12 = (wsptr[2] - wsptr[6]) * ((FAST_FLOAT) 1.414213562) - tmp13;
tmp0 = tmp10 + tmp13;
tmp3 = tmp10 - tmp13;
tmp1 = tmp11 + tmp12;
tmp2 = tmp11 - tmp12;
/* Odd part */
z13 = wsptr[5] + wsptr[3];
z10 = wsptr[5] - wsptr[3];
z11 = wsptr[1] + wsptr[7];
z12 = wsptr[1] - wsptr[7];
tmp7 = z11 + z13;
tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562);
z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */
tmp10 = ((FAST_FLOAT) 1.082392200) * z12 - z5; /* 2*(c2-c6) */
tmp12 = ((FAST_FLOAT) -2.613125930) * z10 + z5; /* -2*(c2+c6) */
tmp6 = tmp12 - tmp7;
tmp5 = tmp11 - tmp6;
tmp4 = tmp10 + tmp5;
/* Final output stage: scale down by a factor of 8 and range-limit */
outptr[0] = range_limit[(int) DESCALE((INT32) (tmp0 + tmp7), 3)
& RANGE_MASK];
outptr[7] = range_limit[(int) DESCALE((INT32) (tmp0 - tmp7), 3)
& RANGE_MASK];
outptr[1] = range_limit[(int) DESCALE((INT32) (tmp1 + tmp6), 3)
& RANGE_MASK];
outptr[6] = range_limit[(int) DESCALE((INT32) (tmp1 - tmp6), 3)
& RANGE_MASK];
outptr[2] = range_limit[(int) DESCALE((INT32) (tmp2 + tmp5), 3)
& RANGE_MASK];
outptr[5] = range_limit[(int) DESCALE((INT32) (tmp2 - tmp5), 3)
& RANGE_MASK];
outptr[4] = range_limit[(int) DESCALE((INT32) (tmp3 + tmp4), 3)
& RANGE_MASK];
outptr[3] = range_limit[(int) DESCALE((INT32) (tmp3 - tmp4), 3)
& RANGE_MASK];
wsptr += DCTSIZE; /* advance pointer to next row */
}
}
#endif /* DCT_FLOAT_SUPPORTED */
--- NEW FILE: jerror.h ---
/*
* jerror.h
*
* Copyright (C) 1994-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file defines the error and message codes for the JPEG library.
* Edit this file to add new codes, or to translate the message strings to
* some other language.
* A set of error-reporting macros are defined too. Some applications using
* the JPEG library may wish to include this file to get the error codes
* and/or the macros.
*/
/*
* To define the enum list of message codes, include this file without
* defining macro JMESSAGE. To create a message string table, include it
* again with a suitable JMESSAGE definition (see jerror.c for an example).
*/
#ifndef JMESSAGE
#ifndef JERROR_H
/* First time through, define the enum list */
#define JMAKE_ENUM_LIST
#else
/* Repeated inclusions of this file are no-ops unless JMESSAGE is defined */
#define JMESSAGE(code,string)
#endif /* JERROR_H */
#endif /* JMESSAGE */
#ifdef JMAKE_ENUM_LIST
typedef enum {
#define JMESSAGE(code,string) code ,
#endif /* JMAKE_ENUM_LIST */
JMESSAGE(JMSG_NOMESSAGE, "Bogus message code %d") /* Must be first entry! */
/* For maintenance convenience, list is alphabetical by message code name */
JMESSAGE(JERR_ARITH_NOTIMPL,
"Sorry, there are legal restrictions on arithmetic coding")
JMESSAGE(JERR_BAD_ALIGN_TYPE, "ALIGN_TYPE is wrong, please fix")
JMESSAGE(JERR_BAD_ALLOC_CHUNK, "MAX_ALLOC_CHUNK is wrong, please fix")
JMESSAGE(JERR_BAD_BUFFER_MODE, "Bogus buffer control mode")
JMESSAGE(JERR_BAD_COMPONENT_ID, "Invalid component ID %d in SOS")
JMESSAGE(JERR_BAD_DCT_COEF, "DCT coefficient out of range")
JMESSAGE(JERR_BAD_DCTSIZE, "IDCT output block size %d not supported")
JMESSAGE(JERR_BAD_HUFF_TABLE, "Bogus Huffman table definition")
JMESSAGE(JERR_BAD_IN_COLORSPACE, "Bogus input colorspace")
JMESSAGE(JERR_BAD_J_COLORSPACE, "Bogus JPEG colorspace")
JMESSAGE(JERR_BAD_LENGTH, "Bogus marker length")
JMESSAGE(JERR_BAD_LIB_VERSION,
"Wrong JPEG library version: library is %d, caller expects %d")
JMESSAGE(JERR_BAD_MCU_SIZE, "Sampling factors too large for interleaved scan")
JMESSAGE(JERR_BAD_POOL_ID, "Invalid memory pool code %d")
JMESSAGE(JERR_BAD_PRECISION, "Unsupported JPEG data precision %d")
JMESSAGE(JERR_BAD_PROGRESSION,
"Invalid progressive parameters Ss=%d Se=%d Ah=%d Al=%d")
JMESSAGE(JERR_BAD_PROG_SCRIPT,
"Invalid progressive parameters at scan script entry %d")
JMESSAGE(JERR_BAD_SAMPLING, "Bogus sampling factors")
JMESSAGE(JERR_BAD_SCAN_SCRIPT, "Invalid scan script at entry %d")
JMESSAGE(JERR_BAD_STATE, "Improper call to JPEG library in state %d")
JMESSAGE(JERR_BAD_STRUCT_SIZE,
"JPEG parameter struct mismatch: library thinks size is %u, caller expects %u")
JMESSAGE(JERR_BAD_VIRTUAL_ACCESS, "Bogus virtual array access")
JMESSAGE(JERR_BUFFER_SIZE, "Buffer passed to JPEG library is too small")
JMESSAGE(JERR_CANT_SUSPEND, "Suspension not allowed here")
JMESSAGE(JERR_CCIR601_NOTIMPL, "CCIR601 sampling not implemented yet")
JMESSAGE(JERR_COMPONENT_COUNT, "Too many color components: %d, max %d")
JMESSAGE(JERR_CONVERSION_NOTIMPL, "Unsupported color conversion request")
JMESSAGE(JERR_DAC_INDEX, "Bogus DAC index %d")
JMESSAGE(JERR_DAC_VALUE, "Bogus DAC value 0x%x")
JMESSAGE(JERR_DHT_INDEX, "Bogus DHT index %d")
JMESSAGE(JERR_DQT_INDEX, "Bogus DQT index %d")
JMESSAGE(JERR_EMPTY_IMAGE, "Empty JPEG image (DNL not supported)")
JMESSAGE(JERR_EMS_READ, "Read from EMS failed")
JMESSAGE(JERR_EMS_WRITE, "Write to EMS failed")
JMESSAGE(JERR_EOI_EXPECTED, "Didn't expect more than one scan")
JMESSAGE(JERR_FILE_READ, "Input file read error")
JMESSAGE(JERR_FILE_WRITE, "Output file write error --- out of disk space?")
JMESSAGE(JERR_FRACT_SAMPLE_NOTIMPL, "Fractional sampling not implemented yet")
JMESSAGE(JERR_HUFF_CLEN_OVERFLOW, "Huffman code size table overflow")
JMESSAGE(JERR_HUFF_MISSING_CODE, "Missing Huffman code table entry")
JMESSAGE(JERR_IMAGE_TOO_BIG, "Maximum supported image dimension is %u pixels")
JMESSAGE(JERR_INPUT_EMPTY, "Empty input file")
JMESSAGE(JERR_INPUT_EOF, "Premature end of input file")
JMESSAGE(JERR_MISMATCHED_QUANT_TABLE,
"Cannot transcode due to multiple use of quantization table %d")
JMESSAGE(JERR_MISSING_DATA, "Scan script does not transmit all data")
JMESSAGE(JERR_MODE_CHANGE, "Invalid color quantization mode change")
JMESSAGE(JERR_NOTIMPL, "Not implemented yet")
JMESSAGE(JERR_NOT_COMPILED, "Requested feature was omitted at compile time")
JMESSAGE(JERR_NO_BACKING_STORE, "Backing store not supported")
JMESSAGE(JERR_NO_HUFF_TABLE, "Huffman table 0x%02x was not defined")
JMESSAGE(JERR_NO_IMAGE, "JPEG datastream contains no image")
JMESSAGE(JERR_NO_QUANT_TABLE, "Quantization table 0x%02x was not defined")
JMESSAGE(JERR_NO_SOI, "Not a JPEG file: starts with 0x%02x 0x%02x")
JMESSAGE(JERR_OUT_OF_MEMORY, "Insufficient memory (case %d)")
JMESSAGE(JERR_QUANT_COMPONENTS,
"Cannot quantize more than %d color components")
JMESSAGE(JERR_QUANT_FEW_COLORS, "Cannot quantize to fewer than %d colors")
JMESSAGE(JERR_QUANT_MANY_COLORS, "Cannot quantize to more than %d colors")
JMESSAGE(JERR_SOF_DUPLICATE, "Invalid JPEG file structure: two SOF markers")
JMESSAGE(JERR_SOF_NO_SOS, "Invalid JPEG file structure: missing SOS marker")
JMESSAGE(JERR_SOF_UNSUPPORTED, "Unsupported JPEG process: SOF type 0x%02x")
JMESSAGE(JERR_SOI_DUPLICATE, "Invalid JPEG file structure: two SOI markers")
JMESSAGE(JERR_SOS_NO_SOF, "Invalid JPEG file structure: SOS before SOF")
JMESSAGE(JERR_TFILE_CREATE, "Failed to create temporary file %s")
JMESSAGE(JERR_TFILE_READ, "Read failed on temporary file")
JMESSAGE(JERR_TFILE_SEEK, "Seek failed on temporary file")
JMESSAGE(JERR_TFILE_WRITE,
"Write failed on temporary file --- out of disk space?")
JMESSAGE(JERR_TOO_LITTLE_DATA, "Application transferred too few scanlines")
JMESSAGE(JERR_UNKNOWN_MARKER, "Unsupported marker type 0x%02x")
JMESSAGE(JERR_VIRTUAL_BUG, "Virtual array controller messed up")
JMESSAGE(JERR_WIDTH_OVERFLOW, "Image too wide for this implementation")
JMESSAGE(JERR_XMS_READ, "Read from XMS failed")
JMESSAGE(JERR_XMS_WRITE, "Write to XMS failed")
JMESSAGE(JMSG_COPYRIGHT, JCOPYRIGHT)
JMESSAGE(JMSG_VERSION, JVERSION)
JMESSAGE(JTRC_16BIT_TABLES,
"Caution: quantization tables are too coarse for baseline JPEG")
JMESSAGE(JTRC_ADOBE,
"Adobe APP14 marker: version %d, flags 0x%04x 0x%04x, transform %d")
JMESSAGE(JTRC_APP0, "Unknown APP0 marker (not JFIF), length %u")
JMESSAGE(JTRC_APP14, "Unknown APP14 marker (not Adobe), length %u")
JMESSAGE(JTRC_DAC, "Define Arithmetic Table 0x%02x: 0x%02x")
JMESSAGE(JTRC_DHT, "Define Huffman Table 0x%02x")
JMESSAGE(JTRC_DQT, "Define Quantization Table %d precision %d")
JMESSAGE(JTRC_DRI, "Define Restart Interval %u")
JMESSAGE(JTRC_EMS_CLOSE, "Freed EMS handle %u")
JMESSAGE(JTRC_EMS_OPEN, "Obtained EMS handle %u")
JMESSAGE(JTRC_EOI, "End Of Image")
JMESSAGE(JTRC_HUFFBITS, " %3d %3d %3d %3d %3d %3d %3d %3d")
JMESSAGE(JTRC_JFIF, "JFIF APP0 marker: version %d.%02d, density %dx%d %d")
JMESSAGE(JTRC_JFIF_BADTHUMBNAILSIZE,
"Warning: thumbnail image size does not match data length %u")
JMESSAGE(JTRC_JFIF_EXTENSION,
"JFIF extension marker: type 0x%02x, length %u")
JMESSAGE(JTRC_JFIF_THUMBNAIL, " with %d x %d thumbnail image")
JMESSAGE(JTRC_MISC_MARKER, "Miscellaneous marker 0x%02x, length %u")
JMESSAGE(JTRC_PARMLESS_MARKER, "Unexpected marker 0x%02x")
JMESSAGE(JTRC_QUANTVALS, " %4u %4u %4u %4u %4u %4u %4u %4u")
JMESSAGE(JTRC_QUANT_3_NCOLORS, "Quantizing to %d = %d*%d*%d colors")
JMESSAGE(JTRC_QUANT_NCOLORS, "Quantizing to %d colors")
JMESSAGE(JTRC_QUANT_SELECTED, "Selected %d colors for quantization")
JMESSAGE(JTRC_RECOVERY_ACTION, "At marker 0x%02x, recovery action %d")
JMESSAGE(JTRC_RST, "RST%d")
JMESSAGE(JTRC_SMOOTH_NOTIMPL,
"Smoothing not supported with nonstandard sampling ratios")
JMESSAGE(JTRC_SOF, "Start Of Frame 0x%02x: width=%u, height=%u, components=%d")
JMESSAGE(JTRC_SOF_COMPONENT, " Component %d: %dhx%dv q=%d")
JMESSAGE(JTRC_SOI, "Start of Image")
JMESSAGE(JTRC_SOS, "Start Of Scan: %d components")
JMESSAGE(JTRC_SOS_COMPONENT, " Component %d: dc=%d ac=%d")
JMESSAGE(JTRC_SOS_PARAMS, " Ss=%d, Se=%d, Ah=%d, Al=%d")
JMESSAGE(JTRC_TFILE_CLOSE, "Closed temporary file %s")
JMESSAGE(JTRC_TFILE_OPEN, "Opened temporary file %s")
JMESSAGE(JTRC_THUMB_JPEG,
"JFIF extension marker: JPEG-compressed thumbnail image, length %u")
JMESSAGE(JTRC_THUMB_PALETTE,
"JFIF extension marker: palette thumbnail image, length %u")
JMESSAGE(JTRC_THUMB_RGB,
"JFIF extension marker: RGB thumbnail image, length %u")
JMESSAGE(JTRC_UNKNOWN_IDS,
"Unrecognized component IDs %d %d %d, assuming YCbCr")
JMESSAGE(JTRC_XMS_CLOSE, "Freed XMS handle %u")
JMESSAGE(JTRC_XMS_OPEN, "Obtained XMS handle %u")
JMESSAGE(JWRN_ADOBE_XFORM, "Unknown Adobe color transform code %d")
JMESSAGE(JWRN_BOGUS_PROGRESSION,
"Inconsistent progression sequence for component %d coefficient %d")
JMESSAGE(JWRN_EXTRANEOUS_DATA,
"Corrupt JPEG data: %u extraneous bytes before marker 0x%02x")
JMESSAGE(JWRN_HIT_MARKER, "Corrupt JPEG data: premature end of data segment")
JMESSAGE(JWRN_HUFF_BAD_CODE, "Corrupt JPEG data: bad Huffman code")
JMESSAGE(JWRN_JFIF_MAJOR, "Warning: unknown JFIF revision number %d.%02d")
JMESSAGE(JWRN_JPEG_EOF, "Premature end of JPEG file")
JMESSAGE(JWRN_MUST_RESYNC,
"Corrupt JPEG data: found marker 0x%02x instead of RST%d")
JMESSAGE(JWRN_NOT_SEQUENTIAL, "Invalid SOS parameters for sequential JPEG")
JMESSAGE(JWRN_TOO_MUCH_DATA, "Application transferred too many scanlines")
#ifdef JMAKE_ENUM_LIST
JMSG_LASTMSGCODE
} J_MESSAGE_CODE;
#undef JMAKE_ENUM_LIST
#endif /* JMAKE_ENUM_LIST */
/* Zap JMESSAGE macro so that future re-inclusions do nothing by default */
#undef JMESSAGE
#ifndef JERROR_H
#define JERROR_H
/* Macros to simplify using the error and trace message stuff */
/* The first parameter is either type of cinfo pointer */
/* Fatal errors (print message and exit) */
#define ERREXIT(cinfo,code) \
((cinfo)->err->msg_code = (code), \
(*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
#define ERREXIT1(cinfo,code,p1) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
#define ERREXIT2(cinfo,code,p1,p2) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(cinfo)->err->msg_parm.i[1] = (p2), \
(*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
#define ERREXIT3(cinfo,code,p1,p2,p3) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(cinfo)->err->msg_parm.i[1] = (p2), \
(cinfo)->err->msg_parm.i[2] = (p3), \
(*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
#define ERREXIT4(cinfo,code,p1,p2,p3,p4) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(cinfo)->err->msg_parm.i[1] = (p2), \
(cinfo)->err->msg_parm.i[2] = (p3), \
(cinfo)->err->msg_parm.i[3] = (p4), \
(*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
#define ERREXITS(cinfo,code,str) \
((cinfo)->err->msg_code = (code), \
strncpy((cinfo)->err->msg_parm.s, (str), JMSG_STR_PARM_MAX), \
(*(cinfo)->err->error_exit) ((j_common_ptr) (cinfo)))
#define MAKESTMT(stuff) do { stuff } while (0)
/* Nonfatal errors (we can keep going, but the data is probably corrupt) */
#define WARNMS(cinfo,code) \
((cinfo)->err->msg_code = (code), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), -1))
#define WARNMS1(cinfo,code,p1) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), -1))
#define WARNMS2(cinfo,code,p1,p2) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(cinfo)->err->msg_parm.i[1] = (p2), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), -1))
/* Informational/debugging messages */
#define TRACEMS(cinfo,lvl,code) \
((cinfo)->err->msg_code = (code), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
#define TRACEMS1(cinfo,lvl,code,p1) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
#define TRACEMS2(cinfo,lvl,code,p1,p2) \
((cinfo)->err->msg_code = (code), \
(cinfo)->err->msg_parm.i[0] = (p1), \
(cinfo)->err->msg_parm.i[1] = (p2), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
#define TRACEMS3(cinfo,lvl,code,p1,p2,p3) \
MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
_mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); \
(cinfo)->err->msg_code = (code); \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
#define TRACEMS4(cinfo,lvl,code,p1,p2,p3,p4) \
MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
_mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); _mp[3] = (p4); \
(cinfo)->err->msg_code = (code); \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
#define TRACEMS5(cinfo,lvl,code,p1,p2,p3,p4,p5) \
MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
_mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); _mp[3] = (p4); \
_mp[4] = (p5); \
(cinfo)->err->msg_code = (code); \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
#define TRACEMS8(cinfo,lvl,code,p1,p2,p3,p4,p5,p6,p7,p8) \
MAKESTMT(int * _mp = (cinfo)->err->msg_parm.i; \
_mp[0] = (p1); _mp[1] = (p2); _mp[2] = (p3); _mp[3] = (p4); \
_mp[4] = (p5); _mp[5] = (p6); _mp[6] = (p7); _mp[7] = (p8); \
(cinfo)->err->msg_code = (code); \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)); )
#define TRACEMSS(cinfo,lvl,code,str) \
((cinfo)->err->msg_code = (code), \
strncpy((cinfo)->err->msg_parm.s, (str), JMSG_STR_PARM_MAX), \
(*(cinfo)->err->emit_message) ((j_common_ptr) (cinfo), (lvl)))
#endif /* JERROR_H */
--- NEW FILE: jdmainct.c ---
/*
* jdmainct.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains the main buffer controller for decompression.
* The main buffer lies between the JPEG decompressor proper and the
* post-processor; it holds downsampled data in the JPEG colorspace.
*
* Note that this code is bypassed in raw-data mode, since the application
* supplies the equivalent of the main buffer in that case.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/*
* In the current system design, the main buffer need never be a full-image
* buffer; any full-height buffers will be found inside the coefficient or
* postprocessing controllers. Nonetheless, the main controller is not
* trivial. Its responsibility is to provide context rows for upsampling/
* rescaling, and doing this in an efficient fashion is a bit tricky.
*
* Postprocessor input data is counted in "row groups". A row group
* is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
* sample rows of each component. (We require DCT_scaled_size values to be
* chosen such that these numbers are integers. In practice DCT_scaled_size
* values will likely be powers of two, so we actually have the stronger
* condition that DCT_scaled_size / min_DCT_scaled_size is an integer.)
* Upsampling will typically produce max_v_samp_factor pixel rows from each
* row group (times any additional scale factor that the upsampler is
* applying).
*
* The coefficient controller will deliver data to us one iMCU row at a time;
* each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or
* exactly min_DCT_scaled_size row groups. (This amount of data corresponds
* to one row of MCUs when the image is fully interleaved.) Note that the
* number of sample rows varies across components, but the number of row
* groups does not. Some garbage sample rows may be included in the last iMCU
* row at the bottom of the image.
*
* Depending on the vertical scaling algorithm used, the upsampler may need
* access to the sample row(s) above and below its current input row group.
* The upsampler is required to set need_context_rows TRUE at global selection
* time if so. When need_context_rows is FALSE, this controller can simply
* obtain one iMCU row at a time from the coefficient controller and dole it
* out as row groups to the postprocessor.
*
* When need_context_rows is TRUE, this controller guarantees that the buffer
* passed to postprocessing contains at least one row group's worth of samples
* above and below the row group(s) being processed. Note that the context
* rows "above" the first passed row group appear at negative row offsets in
* the passed buffer. At the top and bottom of the image, the required
* context rows are manufactured by duplicating the first or last real sample
* row; this avoids having special cases in the upsampling inner loops.
*
* The amount of context is fixed at one row group just because that's a
* convenient number for this controller to work with. The existing
* upsamplers really only need one sample row of context. An upsampler
* supporting arbitrary output rescaling might wish for more than one row
* group of context when shrinking the image; tough, we don't handle that.
* (This is justified by the assumption that downsizing will be handled mostly
* by adjusting the DCT_scaled_size values, so that the actual scale factor at
* the upsample step needn't be much less than one.)
*
* To provide the desired context, we have to retain the last two row groups
* of one iMCU row while reading in the next iMCU row. (The last row group
* can't be processed until we have another row group for its below-context,
* and so we have to save the next-to-last group too for its above-context.)
* We could do this most simply by copying data around in our buffer, but
* that'd be very slow. We can avoid copying any data by creating a rather
* strange pointer structure. Here's how it works. We allocate a workspace
* consisting of M+2 row groups (where M = min_DCT_scaled_size is the number
* of row groups per iMCU row). We create two sets of redundant pointers to
* the workspace. Labeling the physical row groups 0 to M+1, the synthesized
* pointer lists look like this:
* M+1 M-1
* master pointer --> 0 master pointer --> 0
* 1 1
* ... ...
* M-3 M-3
* M-2 M
* M-1 M+1
* M M-2
* M+1 M-1
* 0 0
* We read alternate iMCU rows using each master pointer; thus the last two
* row groups of the previous iMCU row remain un-overwritten in the workspace.
* The pointer lists are set up so that the required context rows appear to
* be adjacent to the proper places when we pass the pointer lists to the
* upsampler.
*
* The above pictures describe the normal state of the pointer lists.
* At top and bottom of the image, we diddle the pointer lists to duplicate
* the first or last sample row as necessary (this is cheaper than copying
* sample rows around).
*
* This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that
* situation each iMCU row provides only one row group so the buffering logic
* must be different (eg, we must read two iMCU rows before we can emit the
* first row group). For now, we simply do not support providing context
* rows when min_DCT_scaled_size is 1. That combination seems unlikely to
* be worth providing --- if someone wants a 1/8th-size preview, they probably
* want it quick and dirty, so a context-free upsampler is sufficient.
*/
/* Private buffer controller object */
typedef struct {
struct jpeg_d_main_controller pub; /* public fields */
/* Pointer to allocated workspace (M or M+2 row groups). */
JSAMPARRAY buffer[MAX_COMPONENTS];
boolean buffer_full; /* Have we gotten an iMCU row from decoder? */
JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */
/* Remaining fields are only used in the context case. */
/* These are the master pointers to the funny-order pointer lists. */
JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */
int whichptr; /* indicates which pointer set is now in use */
int context_state; /* process_data state machine status */
JDIMENSION rowgroups_avail; /* row groups available to postprocessor */
JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */
} my_main_controller;
typedef my_main_controller * my_main_ptr;
/* context_state values: */
#define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */
#define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */
#define CTX_POSTPONED_ROW 2 /* feeding postponed row group */
/* Forward declarations */
METHODDEF(void) process_data_simple_main
JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
METHODDEF(void) process_data_context_main
JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
#ifdef QUANT_2PASS_SUPPORTED
METHODDEF(void) process_data_crank_post
JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
#endif
LOCAL(void)
alloc_funny_pointers (j_decompress_ptr cinfo)
/* Allocate space for the funny pointer lists.
* This is done only once, not once per pass.
*/
{
my_main_ptr main = (my_main_ptr) cinfo->main;
int ci, rgroup;
int M = cinfo->min_DCT_scaled_size;
jpeg_component_info *compptr;
JSAMPARRAY xbuf;
/* Get top-level space for component array pointers.
* We alloc both arrays with one call to save a few cycles.
*/
main->xbuffer[0] = (JSAMPIMAGE)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->num_components * 2 * SIZEOF(JSAMPARRAY));
main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
cinfo->min_DCT_scaled_size; /* height of a row group of component */
/* Get space for pointer lists --- M+4 row groups in each list.
* We alloc both pointer lists with one call to save a few cycles.
*/
xbuf = (JSAMPARRAY)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW));
xbuf += rgroup; /* want one row group at negative offsets */
main->xbuffer[0][ci] = xbuf;
xbuf += rgroup * (M + 4);
main->xbuffer[1][ci] = xbuf;
}
}
LOCAL(void)
make_funny_pointers (j_decompress_ptr cinfo)
/* Create the funny pointer lists discussed in the comments above.
* The actual workspace is already allocated (in main->buffer),
* and the space for the pointer lists is allocated too.
* This routine just fills in the curiously ordered lists.
* This will be repeated at the beginning of each pass.
*/
{
my_main_ptr main = (my_main_ptr) cinfo->main;
int ci, i, rgroup;
int M = cinfo->min_DCT_scaled_size;
jpeg_component_info *compptr;
JSAMPARRAY buf, xbuf0, xbuf1;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
cinfo->min_DCT_scaled_size; /* height of a row group of component */
xbuf0 = main->xbuffer[0][ci];
xbuf1 = main->xbuffer[1][ci];
/* First copy the workspace pointers as-is */
buf = main->buffer[ci];
for (i = 0; i < rgroup * (M + 2); i++) {
xbuf0[i] = xbuf1[i] = buf[i];
}
/* In the second list, put the last four row groups in swapped order */
for (i = 0; i < rgroup * 2; i++) {
xbuf1[rgroup*(M-2) + i] = buf[rgroup*M + i];
xbuf1[rgroup*M + i] = buf[rgroup*(M-2) + i];
}
/* The wraparound pointers at top and bottom will be filled later
* (see set_wraparound_pointers, below). Initially we want the "above"
* pointers to duplicate the first actual data line. This only needs
* to happen in xbuffer[0].
*/
for (i = 0; i < rgroup; i++) {
xbuf0[i - rgroup] = xbuf0[0];
}
}
}
LOCAL(void)
set_wraparound_pointers (j_decompress_ptr cinfo)
/* Set up the "wraparound" pointers at top and bottom of the pointer lists.
* This changes the pointer list state from top-of-image to the normal state.
*/
{
my_main_ptr main = (my_main_ptr) cinfo->main;
int ci, i, rgroup;
int M = cinfo->min_DCT_scaled_size;
jpeg_component_info *compptr;
JSAMPARRAY xbuf0, xbuf1;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
cinfo->min_DCT_scaled_size; /* height of a row group of component */
xbuf0 = main->xbuffer[0][ci];
xbuf1 = main->xbuffer[1][ci];
for (i = 0; i < rgroup; i++) {
xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i];
xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i];
xbuf0[rgroup*(M+2) + i] = xbuf0[i];
xbuf1[rgroup*(M+2) + i] = xbuf1[i];
}
}
}
LOCAL(void)
set_bottom_pointers (j_decompress_ptr cinfo)
/* Change the pointer lists to duplicate the last sample row at the bottom
* of the image. whichptr indicates which xbuffer holds the final iMCU row.
* Also sets rowgroups_avail to indicate number of nondummy row groups in row.
*/
{
my_main_ptr main = (my_main_ptr) cinfo->main;
int ci, i, rgroup, iMCUheight, rows_left;
jpeg_component_info *compptr;
JSAMPARRAY xbuf;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Count sample rows in one iMCU row and in one row group */
iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size;
rgroup = iMCUheight / cinfo->min_DCT_scaled_size;
/* Count nondummy sample rows remaining for this component */
rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight);
if (rows_left == 0) rows_left = iMCUheight;
/* Count nondummy row groups. Should get same answer for each component,
* so we need only do it once.
*/
if (ci == 0) {
main->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1);
}
/* Duplicate the last real sample row rgroup*2 times; this pads out the
* last partial rowgroup and ensures at least one full rowgroup of context.
*/
xbuf = main->xbuffer[main->whichptr][ci];
for (i = 0; i < rgroup * 2; i++) {
xbuf[rows_left + i] = xbuf[rows_left-1];
}
}
}
/*
* Initialize for a processing pass.
*/
METHODDEF(void)
start_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
{
my_main_ptr main = (my_main_ptr) cinfo->main;
switch (pass_mode) {
case JBUF_PASS_THRU:
if (cinfo->upsample->need_context_rows) {
main->pub.process_data = process_data_context_main;
make_funny_pointers(cinfo); /* Create the xbuffer[] lists */
main->whichptr = 0; /* Read first iMCU row into xbuffer[0] */
main->context_state = CTX_PREPARE_FOR_IMCU;
main->iMCU_row_ctr = 0;
} else {
/* Simple case with no context needed */
main->pub.process_data = process_data_simple_main;
}
main->buffer_full = FALSE; /* Mark buffer empty */
main->rowgroup_ctr = 0;
break;
#ifdef QUANT_2PASS_SUPPORTED
case JBUF_CRANK_DEST:
/* For last pass of 2-pass quantization, just crank the postprocessor */
main->pub.process_data = process_data_crank_post;
break;
#endif
default:
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
break;
}
}
/*
* Process some data.
* This handles the simple case where no context is required.
*/
METHODDEF(void)
process_data_simple_main (j_decompress_ptr cinfo,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
my_main_ptr main = (my_main_ptr) cinfo->main;
JDIMENSION rowgroups_avail;
/* Read input data if we haven't filled the main buffer yet */
if (! main->buffer_full) {
if (! (*cinfo->coef->decompress_data) (cinfo, main->buffer))
return; /* suspension forced, can do nothing more */
main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
}
/* There are always min_DCT_scaled_size row groups in an iMCU row. */
rowgroups_avail = (JDIMENSION) cinfo->min_DCT_scaled_size;
/* Note: at the bottom of the image, we may pass extra garbage row groups
* to the postprocessor. The postprocessor has to check for bottom
* of image anyway (at row resolution), so no point in us doing it too.
*/
/* Feed the postprocessor */
(*cinfo->post->post_process_data) (cinfo, main->buffer,
&main->rowgroup_ctr, rowgroups_avail,
output_buf, out_row_ctr, out_rows_avail);
/* Has postprocessor consumed all the data yet? If so, mark buffer empty */
if (main->rowgroup_ctr >= rowgroups_avail) {
main->buffer_full = FALSE;
main->rowgroup_ctr = 0;
}
}
/*
* Process some data.
* This handles the case where context rows must be provided.
*/
METHODDEF(void)
process_data_context_main (j_decompress_ptr cinfo,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
my_main_ptr main = (my_main_ptr) cinfo->main;
/* Read input data if we haven't filled the main buffer yet */
if (! main->buffer_full) {
if (! (*cinfo->coef->decompress_data) (cinfo,
main->xbuffer[main->whichptr]))
return; /* suspension forced, can do nothing more */
main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
main->iMCU_row_ctr++; /* count rows received */
}
/* Postprocessor typically will not swallow all the input data it is handed
* in one call (due to filling the output buffer first). Must be prepared
* to exit and restart. This switch lets us keep track of how far we got.
* Note that each case falls through to the next on successful completion.
*/
switch (main->context_state) {
case CTX_POSTPONED_ROW:
/* Call postprocessor using previously set pointers for postponed row */
(*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr],
&main->rowgroup_ctr, main->rowgroups_avail,
output_buf, out_row_ctr, out_rows_avail);
if (main->rowgroup_ctr < main->rowgroups_avail)
return; /* Need to suspend */
main->context_state = CTX_PREPARE_FOR_IMCU;
if (*out_row_ctr >= out_rows_avail)
return; /* Postprocessor exactly filled output buf */
/*FALLTHROUGH*/
case CTX_PREPARE_FOR_IMCU:
/* Prepare to process first M-1 row groups of this iMCU row */
main->rowgroup_ctr = 0;
main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size - 1);
/* Check for bottom of image: if so, tweak pointers to "duplicate"
* the last sample row, and adjust rowgroups_avail to ignore padding rows.
*/
if (main->iMCU_row_ctr == cinfo->total_iMCU_rows)
set_bottom_pointers(cinfo);
main->context_state = CTX_PROCESS_IMCU;
/*FALLTHROUGH*/
case CTX_PROCESS_IMCU:
/* Call postprocessor using previously set pointers */
(*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr],
&main->rowgroup_ctr, main->rowgroups_avail,
output_buf, out_row_ctr, out_rows_avail);
if (main->rowgroup_ctr < main->rowgroups_avail)
return; /* Need to suspend */
/* After the first iMCU, change wraparound pointers to normal state */
if (main->iMCU_row_ctr == 1)
set_wraparound_pointers(cinfo);
/* Prepare to load new iMCU row using other xbuffer list */
main->whichptr ^= 1; /* 0=>1 or 1=>0 */
main->buffer_full = FALSE;
/* Still need to process last row group of this iMCU row, */
/* which is saved at index M+1 of the other xbuffer */
main->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_scaled_size + 1);
main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size + 2);
main->context_state = CTX_POSTPONED_ROW;
}
}
/*
* Process some data.
* Final pass of two-pass quantization: just call the postprocessor.
* Source data will be the postprocessor controller's internal buffer.
*/
#ifdef QUANT_2PASS_SUPPORTED
METHODDEF(void)
process_data_crank_post (j_decompress_ptr cinfo,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
(*cinfo->post->post_process_data) (cinfo, (JSAMPIMAGE) NULL,
(JDIMENSION *) NULL, (JDIMENSION) 0,
output_buf, out_row_ctr, out_rows_avail);
}
#endif /* QUANT_2PASS_SUPPORTED */
/*
* Initialize main buffer controller.
*/
GLOBAL(void)
jinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
{
my_main_ptr main;
int ci, rgroup, ngroups;
jpeg_component_info *compptr;
main = (my_main_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_main_controller));
cinfo->main = (struct jpeg_d_main_controller *) main;
main->pub.start_pass = start_pass_main;
if (need_full_buffer) /* shouldn't happen */
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
/* Allocate the workspace.
* ngroups is the number of row groups we need.
*/
if (cinfo->upsample->need_context_rows) {
if (cinfo->min_DCT_scaled_size < 2) /* unsupported, see comments above */
ERREXIT(cinfo, JERR_NOTIMPL);
alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */
ngroups = cinfo->min_DCT_scaled_size + 2;
} else {
ngroups = cinfo->min_DCT_scaled_size;
}
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
cinfo->min_DCT_scaled_size; /* height of a row group of component */
main->buffer[ci] = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
compptr->width_in_blocks * compptr->DCT_scaled_size,
(JDIMENSION) (rgroup * ngroups));
}
}
--- NEW FILE: jversion.h ---
/*
* jversion.h
*
* Copyright (C) 1991-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains software version identification.
*/
#define JVERSION "6b 27-Mar-1998"
#define JCOPYRIGHT "Copyright (C) 1998, Thomas G. Lane"
--- NEW FILE: jdmaster.c ---
/*
* jdmaster.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains master control logic for the JPEG decompressor.
* These routines are concerned with selecting the modules to be executed
* and with determining the number of passes and the work to be done in each
* pass.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Private state */
typedef struct {
struct jpeg_decomp_master pub; /* public fields */
int pass_number; /* # of passes completed */
boolean using_merged_upsample; /* TRUE if using merged upsample/cconvert */
/* Saved references to initialized quantizer modules,
* in case we need to switch modes.
*/
struct jpeg_color_quantizer * quantizer_1pass;
struct jpeg_color_quantizer * quantizer_2pass;
} my_decomp_master;
typedef my_decomp_master * my_master_ptr;
/*
* Determine whether merged upsample/color conversion should be used.
* CRUCIAL: this must match the actual capabilities of jdmerge.c!
*/
LOCAL(boolean)
use_merged_upsample (j_decompress_ptr cinfo)
{
#ifdef UPSAMPLE_MERGING_SUPPORTED
/* Merging is the equivalent of plain box-filter upsampling */
if (cinfo->do_fancy_upsampling || cinfo->CCIR601_sampling)
return FALSE;
/* jdmerge.c only supports YCC=>RGB color conversion */
if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 ||
cinfo->out_color_space != JCS_RGB ||
cinfo->out_color_components != RGB_PIXELSIZE)
return FALSE;
/* and it only handles 2h1v or 2h2v sampling ratios */
if (cinfo->comp_info[0].h_samp_factor != 2 ||
cinfo->comp_info[1].h_samp_factor != 1 ||
cinfo->comp_info[2].h_samp_factor != 1 ||
cinfo->comp_info[0].v_samp_factor > 2 ||
cinfo->comp_info[1].v_samp_factor != 1 ||
cinfo->comp_info[2].v_samp_factor != 1)
return FALSE;
/* furthermore, it doesn't work if we've scaled the IDCTs differently */
if (cinfo->comp_info[0].DCT_scaled_size != cinfo->min_DCT_scaled_size ||
cinfo->comp_info[1].DCT_scaled_size != cinfo->min_DCT_scaled_size ||
cinfo->comp_info[2].DCT_scaled_size != cinfo->min_DCT_scaled_size)
return FALSE;
/* ??? also need to test for upsample-time rescaling, when & if supported */
return TRUE; /* by golly, it'll work... */
#else
return FALSE;
#endif
}
/*
* Compute output image dimensions and related values.
* NOTE: this is exported for possible use by application.
* Hence it mustn't do anything that can't be done twice.
* Also note that it may be called before the master module is initialized!
*/
GLOBAL(void)
jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
/* Do computations that are needed before master selection phase */
{
#ifdef IDCT_SCALING_SUPPORTED
int ci;
jpeg_component_info *compptr;
#endif
/* Prevent application from calling me at wrong times */
if (cinfo->global_state != DSTATE_READY)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
#ifdef IDCT_SCALING_SUPPORTED
/* Compute actual output image dimensions and DCT scaling choices. */
if (cinfo->scale_num * 8 <= cinfo->scale_denom) {
/* Provide 1/8 scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width, 8L);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height, 8L);
cinfo->min_DCT_scaled_size = 1;
} else if (cinfo->scale_num * 4 <= cinfo->scale_denom) {
/* Provide 1/4 scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width, 4L);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height, 4L);
cinfo->min_DCT_scaled_size = 2;
} else if (cinfo->scale_num * 2 <= cinfo->scale_denom) {
/* Provide 1/2 scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width, 2L);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height, 2L);
cinfo->min_DCT_scaled_size = 4;
} else {
/* Provide 1/1 scaling */
cinfo->output_width = cinfo->image_width;
cinfo->output_height = cinfo->image_height;
cinfo->min_DCT_scaled_size = DCTSIZE;
}
/* In selecting the actual DCT scaling for each component, we try to
* scale up the chroma components via IDCT scaling rather than upsampling.
* This saves time if the upsampler gets to use 1:1 scaling.
* Note this code assumes that the supported DCT scalings are powers of 2.
*/
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
int ssize = cinfo->min_DCT_scaled_size;
while (ssize < DCTSIZE &&
(compptr->h_samp_factor * ssize * 2 <=
cinfo->max_h_samp_factor * cinfo->min_DCT_scaled_size) &&
(compptr->v_samp_factor * ssize * 2 <=
cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size)) {
ssize = ssize * 2;
}
compptr->DCT_scaled_size = ssize;
}
/* Recompute downsampled dimensions of components;
* application needs to know these if using raw downsampled data.
*/
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Size in samples, after IDCT scaling */
compptr->downsampled_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width *
(long) (compptr->h_samp_factor * compptr->DCT_scaled_size),
(long) (cinfo->max_h_samp_factor * DCTSIZE));
compptr->downsampled_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height *
(long) (compptr->v_samp_factor * compptr->DCT_scaled_size),
(long) (cinfo->max_v_samp_factor * DCTSIZE));
}
#else /* !IDCT_SCALING_SUPPORTED */
/* Hardwire it to "no scaling" */
cinfo->output_width = cinfo->image_width;
cinfo->output_height = cinfo->image_height;
/* jdinput.c has already initialized DCT_scaled_size to DCTSIZE,
* and has computed unscaled downsampled_width and downsampled_height.
*/
#endif /* IDCT_SCALING_SUPPORTED */
/* Report number of components in selected colorspace. */
/* Probably this should be in the color conversion module... */
switch (cinfo->out_color_space) {
case JCS_GRAYSCALE:
cinfo->out_color_components = 1;
break;
case JCS_RGB:
#if RGB_PIXELSIZE != 3
cinfo->out_color_components = RGB_PIXELSIZE;
break;
#endif /* else share code with YCbCr */
case JCS_YCbCr:
cinfo->out_color_components = 3;
break;
case JCS_CMYK:
case JCS_YCCK:
cinfo->out_color_components = 4;
break;
default: /* else must be same colorspace as in file */
cinfo->out_color_components = cinfo->num_components;
break;
}
cinfo->output_components = (cinfo->quantize_colors ? 1 :
cinfo->out_color_components);
/* See if upsampler will want to emit more than one row at a time */
if (use_merged_upsample(cinfo))
cinfo->rec_outbuf_height = cinfo->max_v_samp_factor;
else
cinfo->rec_outbuf_height = 1;
}
/*
* Several decompression processes need to range-limit values to the range
* 0..MAXJSAMPLE; the input value may fall somewhat outside this range
* due to noise introduced by quantization, roundoff error, etc. These
* processes are inner loops and need to be as fast as possible. On most
* machines, particularly CPUs with pipelines or instruction prefetch,
* a (subscript-check-less) C table lookup
* x = sample_range_limit[x];
* is faster than explicit tests
* if (x < 0) x = 0;
* else if (x > MAXJSAMPLE) x = MAXJSAMPLE;
* These processes all use a common table prepared by the routine below.
*
* For most steps we can mathematically guarantee that the initial value
* of x is within MAXJSAMPLE+1 of the legal range, so a table running from
* -(MAXJSAMPLE+1) to 2*MAXJSAMPLE+1 is sufficient. But for the initial
* limiting step (just after the IDCT), a wildly out-of-range value is
* possible if the input data is corrupt. To avoid any chance of indexing
* off the end of memory and getting a bad-pointer trap, we perform the
* post-IDCT limiting thus:
* x = range_limit[x & MASK];
* where MASK is 2 bits wider than legal sample data, ie 10 bits for 8-bit
* samples. Under normal circumstances this is more than enough range and
* a correct output will be generated; with bogus input data the mask will
* cause wraparound, and we will safely generate a bogus-but-in-range output.
* For the post-IDCT step, we want to convert the data from signed to unsigned
* representation by adding CENTERJSAMPLE at the same time that we limit it.
* So the post-IDCT limiting table ends up looking like this:
* CENTERJSAMPLE,CENTERJSAMPLE+1,...,MAXJSAMPLE,
* MAXJSAMPLE (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
* 0 (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
* 0,1,...,CENTERJSAMPLE-1
* Negative inputs select values from the upper half of the table after
* masking.
*
* We can save some space by overlapping the start of the post-IDCT table
* with the simpler range limiting table. The post-IDCT table begins at
* sample_range_limit + CENTERJSAMPLE.
*
* Note that the table is allocated in near data space on PCs; it's small
* enough and used often enough to justify this.
*/
LOCAL(void)
prepare_range_limit_table (j_decompress_ptr cinfo)
/* Allocate and fill in the sample_range_limit table */
{
JSAMPLE * table;
int i;
table = (JSAMPLE *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(5 * (MAXJSAMPLE+1) + CENTERJSAMPLE) * SIZEOF(JSAMPLE));
table += (MAXJSAMPLE+1); /* allow negative subscripts of simple table */
cinfo->sample_range_limit = table;
/* First segment of "simple" table: limit[x] = 0 for x < 0 */
MEMZERO(table - (MAXJSAMPLE+1), (MAXJSAMPLE+1) * SIZEOF(JSAMPLE));
/* Main part of "simple" table: limit[x] = x */
for (i = 0; i <= MAXJSAMPLE; i++)
table[i] = (JSAMPLE) i;
table += CENTERJSAMPLE; /* Point to where post-IDCT table starts */
/* End of simple table, rest of first half of post-IDCT table */
for (i = CENTERJSAMPLE; i < 2*(MAXJSAMPLE+1); i++)
table[i] = MAXJSAMPLE;
/* Second half of post-IDCT table */
MEMZERO(table + (2 * (MAXJSAMPLE+1)),
(2 * (MAXJSAMPLE+1) - CENTERJSAMPLE) * SIZEOF(JSAMPLE));
MEMCOPY(table + (4 * (MAXJSAMPLE+1) - CENTERJSAMPLE),
cinfo->sample_range_limit, CENTERJSAMPLE * SIZEOF(JSAMPLE));
}
/*
* Master selection of decompression modules.
* This is done once at jpeg_start_decompress time. We determine
* which modules will be used and give them appropriate initialization calls.
* We also initialize the decompressor input side to begin consuming data.
*
* Since jpeg_read_header has finished, we know what is in the SOF
* and (first) SOS markers. We also have all the application parameter
* settings.
*/
LOCAL(void)
master_selection (j_decompress_ptr cinfo)
{
my_master_ptr master = (my_master_ptr) cinfo->master;
boolean use_c_buffer;
long samplesperrow;
JDIMENSION jd_samplesperrow;
/* Initialize dimensions and other stuff */
jpeg_calc_output_dimensions(cinfo);
prepare_range_limit_table(cinfo);
/* Width of an output scanline must be representable as JDIMENSION. */
samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components;
jd_samplesperrow = (JDIMENSION) samplesperrow;
if ((long) jd_samplesperrow != samplesperrow)
ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
/* Initialize my private state */
master->pass_number = 0;
master->using_merged_upsample = use_merged_upsample(cinfo);
/* Color quantizer selection */
master->quantizer_1pass = NULL;
master->quantizer_2pass = NULL;
/* No mode changes if not using buffered-image mode. */
if (! cinfo->quantize_colors || ! cinfo->buffered_image) {
cinfo->enable_1pass_quant = FALSE;
cinfo->enable_external_quant = FALSE;
cinfo->enable_2pass_quant = FALSE;
}
if (cinfo->quantize_colors) {
if (cinfo->raw_data_out)
ERREXIT(cinfo, JERR_NOTIMPL);
/* 2-pass quantizer only works in 3-component color space. */
if (cinfo->out_color_components != 3) {
cinfo->enable_1pass_quant = TRUE;
cinfo->enable_external_quant = FALSE;
cinfo->enable_2pass_quant = FALSE;
cinfo->colormap = NULL;
} else if (cinfo->colormap != NULL) {
cinfo->enable_external_quant = TRUE;
} else if (cinfo->two_pass_quantize) {
cinfo->enable_2pass_quant = TRUE;
} else {
cinfo->enable_1pass_quant = TRUE;
}
if (cinfo->enable_1pass_quant) {
#ifdef QUANT_1PASS_SUPPORTED
jinit_1pass_quantizer(cinfo);
master->quantizer_1pass = cinfo->cquantize;
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
}
/* We use the 2-pass code to map to external colormaps. */
if (cinfo->enable_2pass_quant || cinfo->enable_external_quant) {
#ifdef QUANT_2PASS_SUPPORTED
jinit_2pass_quantizer(cinfo);
master->quantizer_2pass = cinfo->cquantize;
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
}
/* If both quantizers are initialized, the 2-pass one is left active;
* this is necessary for starting with quantization to an external map.
*/
}
/* Post-processing: in particular, color conversion first */
if (! cinfo->raw_data_out) {
if (master->using_merged_upsample) {
#ifdef UPSAMPLE_MERGING_SUPPORTED
jinit_merged_upsampler(cinfo); /* does color conversion too */
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
} else {
jinit_color_deconverter(cinfo);
jinit_upsampler(cinfo);
}
jinit_d_post_controller(cinfo, cinfo->enable_2pass_quant);
}
/* Inverse DCT */
jinit_inverse_dct(cinfo);
/* Entropy decoding: either Huffman or arithmetic coding. */
if (cinfo->arith_code) {
ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
} else {
if (cinfo->progressive_mode) {
#ifdef D_PROGRESSIVE_SUPPORTED
jinit_phuff_decoder(cinfo);
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
} else
jinit_huff_decoder(cinfo);
}
/* Initialize principal buffer controllers. */
use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image;
jinit_d_coef_controller(cinfo, use_c_buffer);
if (! cinfo->raw_data_out)
jinit_d_main_controller(cinfo, FALSE /* never need full buffer here */);
/* We can now tell the memory manager to allocate virtual arrays. */
(*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
/* Initialize input side of decompressor to consume first scan. */
(*cinfo->inputctl->start_input_pass) (cinfo);
#ifdef D_MULTISCAN_FILES_SUPPORTED
/* If jpeg_start_decompress will read the whole file, initialize
* progress monitoring appropriately. The input step is counted
* as one pass.
*/
if (cinfo->progress != NULL && ! cinfo->buffered_image &&
cinfo->inputctl->has_multiple_scans) {
int nscans;
/* Estimate number of scans to set pass_limit. */
if (cinfo->progressive_mode) {
/* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
nscans = 2 + 3 * cinfo->num_components;
} else {
/* For a nonprogressive multiscan file, estimate 1 scan per component. */
nscans = cinfo->num_components;
}
cinfo->progress->pass_counter = 0L;
cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
cinfo->progress->completed_passes = 0;
cinfo->progress->total_passes = (cinfo->enable_2pass_quant ? 3 : 2);
/* Count the input pass as done */
master->pass_number++;
}
#endif /* D_MULTISCAN_FILES_SUPPORTED */
}
/*
* Per-pass setup.
* This is called at the beginning of each output pass. We determine which
* modules will be active during this pass and give them appropriate
* start_pass calls. We also set is_dummy_pass to indicate whether this
* is a "real" output pass or a dummy pass for color quantization.
* (In the latter case, jdapistd.c will crank the pass to completion.)
*/
METHODDEF(void)
prepare_for_output_pass (j_decompress_ptr cinfo)
{
my_master_ptr master = (my_master_ptr) cinfo->master;
if (master->pub.is_dummy_pass) {
#ifdef QUANT_2PASS_SUPPORTED
/* Final pass of 2-pass quantization */
master->pub.is_dummy_pass = FALSE;
(*cinfo->cquantize->start_pass) (cinfo, FALSE);
(*cinfo->post->start_pass) (cinfo, JBUF_CRANK_DEST);
(*cinfo->main->start_pass) (cinfo, JBUF_CRANK_DEST);
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* QUANT_2PASS_SUPPORTED */
} else {
if (cinfo->quantize_colors && cinfo->colormap == NULL) {
/* Select new quantization method */
if (cinfo->two_pass_quantize && cinfo->enable_2pass_quant) {
cinfo->cquantize = master->quantizer_2pass;
master->pub.is_dummy_pass = TRUE;
} else if (cinfo->enable_1pass_quant) {
cinfo->cquantize = master->quantizer_1pass;
} else {
ERREXIT(cinfo, JERR_MODE_CHANGE);
}
}
(*cinfo->idct->start_pass) (cinfo);
(*cinfo->coef->start_output_pass) (cinfo);
if (! cinfo->raw_data_out) {
if (! master->using_merged_upsample)
(*cinfo->cconvert->start_pass) (cinfo);
(*cinfo->upsample->start_pass) (cinfo);
if (cinfo->quantize_colors)
(*cinfo->cquantize->start_pass) (cinfo, master->pub.is_dummy_pass);
(*cinfo->post->start_pass) (cinfo,
(master->pub.is_dummy_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
(*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
}
}
/* Set up progress monitor's pass info if present */
if (cinfo->progress != NULL) {
cinfo->progress->completed_passes = master->pass_number;
cinfo->progress->total_passes = master->pass_number +
(master->pub.is_dummy_pass ? 2 : 1);
/* In buffered-image mode, we assume one more output pass if EOI not
* yet reached, but no more passes if EOI has been reached.
*/
if (cinfo->buffered_image && ! cinfo->inputctl->eoi_reached) {
cinfo->progress->total_passes += (cinfo->enable_2pass_quant ? 2 : 1);
}
}
}
/*
* Finish up at end of an output pass.
*/
METHODDEF(void)
finish_output_pass (j_decompress_ptr cinfo)
{
my_master_ptr master = (my_master_ptr) cinfo->master;
if (cinfo->quantize_colors)
(*cinfo->cquantize->finish_pass) (cinfo);
master->pass_number++;
}
#ifdef D_MULTISCAN_FILES_SUPPORTED
/*
* Switch to a new external colormap between output passes.
*/
GLOBAL(void)
jpeg_new_colormap (j_decompress_ptr cinfo)
{
my_master_ptr master = (my_master_ptr) cinfo->master;
/* Prevent application from calling me at wrong times */
if (cinfo->global_state != DSTATE_BUFIMAGE)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
if (cinfo->quantize_colors && cinfo->enable_external_quant &&
cinfo->colormap != NULL) {
/* Select 2-pass quantizer for external colormap use */
cinfo->cquantize = master->quantizer_2pass;
/* Notify quantizer of colormap change */
(*cinfo->cquantize->new_color_map) (cinfo);
master->pub.is_dummy_pass = FALSE; /* just in case */
} else
ERREXIT(cinfo, JERR_MODE_CHANGE);
}
#endif /* D_MULTISCAN_FILES_SUPPORTED */
/*
* Initialize master decompression control and select active modules.
* This is performed at the start of jpeg_start_decompress.
*/
GLOBAL(void)
jinit_master_decompress (j_decompress_ptr cinfo)
{
my_master_ptr master;
master = (my_master_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_decomp_master));
cinfo->master = (struct jpeg_decomp_master *) master;
master->pub.prepare_for_output_pass = prepare_for_output_pass;
master->pub.finish_output_pass = finish_output_pass;
master->pub.is_dummy_pass = FALSE;
master_selection(cinfo);
}
--- NEW FILE: jerror.c ---
/*
* jerror.c
*
* Copyright (C) 1991-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains simple error-reporting and trace-message routines.
* These are suitable for Unix-like systems and others where writing to
* stderr is the right thing to do. Many applications will want to replace
* some or all of these routines.
*
* If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,
* you get a Windows-specific hack to display error messages in a dialog box.
* It ain't much, but it beats dropping error messages into the bit bucket,
* which is what happens to output to stderr under most Windows C compilers.
*
* These routines are used by both the compression and decompression code.
*/
/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
#include "jinclude.h"
#include "jpeglib.h"
#include "jversion.h"
#include "jerror.h"
#ifdef USE_WINDOWS_MESSAGEBOX
#include <windows.h>
#endif
#ifndef EXIT_FAILURE /* define exit() codes if not provided */
#define EXIT_FAILURE 1
#endif
/*
* Create the message string table.
* We do this from the master message list in jerror.h by re-reading
* jerror.h with a suitable definition for macro JMESSAGE.
* The message table is made an external symbol just in case any applications
* want to refer to it directly.
*/
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_std_message_table jMsgTable
#endif
#define JMESSAGE(code,string) string ,
const char * const jpeg_std_message_table[] = {
#include "jerror.h"
NULL
};
/*
* Error exit handler: must not return to caller.
*
* Applications may override this if they want to get control back after
* an error. Typically one would longjmp somewhere instead of exiting.
* The setjmp buffer can be made a private field within an expanded error
* handler object. Note that the info needed to generate an error message
* is stored in the error object, so you can generate the message now or
* later, at your convenience.
* You should make sure that the JPEG object is cleaned up (with jpeg_abort
* or jpeg_destroy) at some point.
*/
METHODDEF(void)
error_exit (j_common_ptr cinfo)
{
/* Always display the message */
(*cinfo->err->output_message) (cinfo);
/* Let the memory manager delete any temp files before we die */
jpeg_destroy(cinfo);
exit(EXIT_FAILURE);
}
/*
* Actual output of an error or trace message.
* Applications may override this method to send JPEG messages somewhere
* other than stderr.
*
* On Windows, printing to stderr is generally completely useless,
* so we provide optional code to produce an error-dialog popup.
* Most Windows applications will still prefer to override this routine,
* but if they don't, it'll do something at least marginally useful.
*
* NOTE: to use the library in an environment that doesn't support the
* C stdio library, you may have to delete the call to fprintf() entirely,
* not just not use this routine.
*/
METHODDEF(void)
output_message (j_common_ptr cinfo)
{
char buffer[JMSG_LENGTH_MAX];
/* Create the message */
(*cinfo->err->format_message) (cinfo, buffer);
#ifdef USE_WINDOWS_MESSAGEBOX
/* Display it in a message dialog box */
MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",
MB_OK | MB_ICONERROR);
#else
/* Send it to stderr, adding a newline */
fprintf(stderr, "%s\n", buffer);
#endif
}
/*
* Decide whether to emit a trace or warning message.
* msg_level is one of:
* -1: recoverable corrupt-data warning, may want to abort.
* 0: important advisory messages (always display to user).
* 1: first level of tracing detail.
* 2,3,...: successively more detailed tracing messages.
* An application might override this method if it wanted to abort on warnings
* or change the policy about which messages to display.
*/
METHODDEF(void)
emit_message (j_common_ptr cinfo, int msg_level)
{
struct jpeg_error_mgr * err = cinfo->err;
if (msg_level < 0) {
/* It's a warning message. Since corrupt files may generate many warnings,
* the policy implemented here is to show only the first warning,
* unless trace_level >= 3.
*/
if (err->num_warnings == 0 || err->trace_level >= 3)
(*err->output_message) (cinfo);
/* Always count warnings in num_warnings. */
err->num_warnings++;
} else {
/* It's a trace message. Show it if trace_level >= msg_level. */
if (err->trace_level >= msg_level)
(*err->output_message) (cinfo);
}
}
/*
* Format a message string for the most recent JPEG error or message.
* The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
* characters. Note that no '\n' character is added to the string.
* Few applications should need to override this method.
*/
METHODDEF(void)
format_message (j_common_ptr cinfo, char * buffer)
{
struct jpeg_error_mgr * err = cinfo->err;
int msg_code = err->msg_code;
const char * msgtext = NULL;
const char * msgptr;
char ch;
boolean isstring;
/* Look up message string in proper table */
if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
msgtext = err->jpeg_message_table[msg_code];
} else if (err->addon_message_table != NULL &&
msg_code >= err->first_addon_message &&
msg_code <= err->last_addon_message) {
msgtext = err->addon_message_table[msg_code - err->first_addon_message];
}
/* Defend against bogus message number */
if (msgtext == NULL) {
err->msg_parm.i[0] = msg_code;
msgtext = err->jpeg_message_table[0];
}
/* Check for string parameter, as indicated by %s in the message text */
isstring = FALSE;
msgptr = msgtext;
while ((ch = *msgptr++) != '\0') {
if (ch == '%') {
if (*msgptr == 's') isstring = TRUE;
break;
}
}
/* Format the message into the passed buffer */
if (isstring)
sprintf(buffer, msgtext, err->msg_parm.s);
else
sprintf(buffer, msgtext,
err->msg_parm.i[0], err->msg_parm.i[1],
err->msg_parm.i[2], err->msg_parm.i[3],
err->msg_parm.i[4], err->msg_parm.i[5],
err->msg_parm.i[6], err->msg_parm.i[7]);
}
/*
* Reset error state variables at start of a new image.
* This is called during compression startup to reset trace/error
* processing to default state, without losing any application-specific
* method pointers. An application might possibly want to override
* this method if it has additional error processing state.
*/
METHODDEF(void)
reset_error_mgr (j_common_ptr cinfo)
{
cinfo->err->num_warnings = 0;
/* trace_level is not reset since it is an application-supplied parameter */
cinfo->err->msg_code = 0; /* may be useful as a flag for "no error" */
}
/*
* Fill in the standard error-handling methods in a jpeg_error_mgr object.
* Typical call is:
* struct jpeg_compress_struct cinfo;
* struct jpeg_error_mgr err;
*
* cinfo.err = jpeg_std_error(&err);
* after which the application may override some of the methods.
*/
GLOBAL(struct jpeg_error_mgr *)
jpeg_std_error (struct jpeg_error_mgr * err)
{
err->error_exit = error_exit;
err->emit_message = emit_message;
err->output_message = output_message;
err->format_message = format_message;
err->reset_error_mgr = reset_error_mgr;
err->trace_level = 0; /* default = no tracing */
err->num_warnings = 0; /* no warnings emitted yet */
err->msg_code = 0; /* may be useful as a flag for "no error" */
/* Initialize message table pointers */
err->jpeg_message_table = jpeg_std_message_table;
err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
err->addon_message_table = NULL;
err->first_addon_message = 0; /* for safety */
err->last_addon_message = 0;
return err;
}
--- NEW FILE: jmemsys.h ---
/*
* jmemsys.h
*
* Copyright (C) 1992-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This include file defines the interface between the system-independent
* and system-dependent portions of the JPEG memory manager. No other
* modules need include it. (The system-independent portion is jmemmgr.c;
* there are several different versions of the system-dependent portion.)
*
* This file works as-is for the system-dependent memory managers supplied
* in the IJG distribution. You may need to modify it if you write a
* custom memory manager. If system-dependent changes are needed in
* this file, the best method is to #ifdef them based on a configuration
* symbol supplied in jconfig.h, as we have done with USE_MSDOS_MEMMGR
* and USE_MAC_MEMMGR.
*/
/* Short forms of external names for systems with brain-damaged linkers. */
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_get_small jGetSmall
#define jpeg_free_small jFreeSmall
#define jpeg_get_large jGetLarge
#define jpeg_free_large jFreeLarge
#define jpeg_mem_available jMemAvail
#define jpeg_open_backing_store jOpenBackStore
#define jpeg_mem_init jMemInit
#define jpeg_mem_term jMemTerm
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/*
* These two functions are used to allocate and release small chunks of
* memory. (Typically the total amount requested through jpeg_get_small is
* no more than 20K or so; this will be requested in chunks of a few K each.)
* Behavior should be the same as for the standard library functions malloc
* and free; in particular, jpeg_get_small must return NULL on failure.
* On most systems, these ARE malloc and free. jpeg_free_small is passed the
* size of the object being freed, just in case it's needed.
* On an 80x86 machine using small-data memory model, these manage near heap.
*/
EXTERN(void *) jpeg_get_small JPP((j_common_ptr cinfo, size_t sizeofobject));
EXTERN(void) jpeg_free_small JPP((j_common_ptr cinfo, void * object,
size_t sizeofobject));
/*
* These two functions are used to allocate and release large chunks of
* memory (up to the total free space designated by jpeg_mem_available).
* The interface is the same as above, except that on an 80x86 machine,
* far pointers are used. On most other machines these are identical to
* the jpeg_get/free_small routines; but we keep them separate anyway,
* in case a different allocation strategy is desirable for large chunks.
*/
EXTERN(void FAR *) jpeg_get_large JPP((j_common_ptr cinfo,
size_t sizeofobject));
EXTERN(void) jpeg_free_large JPP((j_common_ptr cinfo, void FAR * object,
size_t sizeofobject));
/*
* The macro MAX_ALLOC_CHUNK designates the maximum number of bytes that may
* be requested in a single call to jpeg_get_large (and jpeg_get_small for that
* matter, but that case should never come into play). This macro is needed
* to model the 64Kb-segment-size limit of far addressing on 80x86 machines.
* On those machines, we expect that jconfig.h will provide a proper value.
* On machines with 32-bit flat address spaces, any large constant may be used.
*
* NB: jmemmgr.c expects that MAX_ALLOC_CHUNK will be representable as type
* size_t and will be a multiple of sizeof(align_type).
*/
#ifndef MAX_ALLOC_CHUNK /* may be overridden in jconfig.h */
#define MAX_ALLOC_CHUNK 1000000000L
#endif
/*
* This routine computes the total space still available for allocation by
* jpeg_get_large. If more space than this is needed, backing store will be
* used. NOTE: any memory already allocated must not be counted.
*
* There is a minimum space requirement, corresponding to the minimum
* feasible buffer sizes; jmemmgr.c will request that much space even if
* jpeg_mem_available returns zero. The maximum space needed, enough to hold
* all working storage in memory, is also passed in case it is useful.
* Finally, the total space already allocated is passed. If no better
* method is available, cinfo->mem->max_memory_to_use - already_allocated
* is often a suitable calculation.
*
* It is OK for jpeg_mem_available to underestimate the space available
* (that'll just lead to more backing-store access than is really necessary).
* However, an overestimate will lead to failure. Hence it's wise to subtract
* a slop factor from the true available space. 5% should be enough.
*
* On machines with lots of virtual memory, any large constant may be returned.
* Conversely, zero may be returned to always use the minimum amount of memory.
*/
EXTERN(long) jpeg_mem_available JPP((j_common_ptr cinfo,
long min_bytes_needed,
long max_bytes_needed,
long already_allocated));
/*
* This structure holds whatever state is needed to access a single
* backing-store object. The read/write/close method pointers are called
* by jmemmgr.c to manipulate the backing-store object; all other fields
* are private to the system-dependent backing store routines.
*/
#define TEMP_NAME_LENGTH 64 /* max length of a temporary file's name */
#ifdef USE_MSDOS_MEMMGR /* DOS-specific junk */
typedef unsigned short XMSH; /* type of extended-memory handles */
typedef unsigned short EMSH; /* type of expanded-memory handles */
typedef union {
short file_handle; /* DOS file handle if it's a temp file */
XMSH xms_handle; /* handle if it's a chunk of XMS */
EMSH ems_handle; /* handle if it's a chunk of EMS */
} handle_union;
#endif /* USE_MSDOS_MEMMGR */
#ifdef USE_MAC_MEMMGR /* Mac-specific junk */
#include <Files.h>
#endif /* USE_MAC_MEMMGR */
typedef struct backing_store_struct * backing_store_ptr;
typedef struct backing_store_struct {
/* Methods for reading/writing/closing this backing-store object */
JMETHOD(void, read_backing_store, (j_common_ptr cinfo,
backing_store_ptr info,
void FAR * buffer_address,
long file_offset, long byte_count));
JMETHOD(void, write_backing_store, (j_common_ptr cinfo,
backing_store_ptr info,
void FAR * buffer_address,
long file_offset, long byte_count));
JMETHOD(void, close_backing_store, (j_common_ptr cinfo,
backing_store_ptr info));
/* Private fields for system-dependent backing-store management */
#ifdef USE_MSDOS_MEMMGR
/* For the MS-DOS manager (jmemdos.c), we need: */
handle_union handle; /* reference to backing-store storage object */
char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
#else
#ifdef USE_MAC_MEMMGR
/* For the Mac manager (jmemmac.c), we need: */
short temp_file; /* file reference number to temp file */
FSSpec tempSpec; /* the FSSpec for the temp file */
char temp_name[TEMP_NAME_LENGTH]; /* name if it's a file */
#else
/* For a typical implementation with temp files, we need: */
FILE * temp_file; /* stdio reference to temp file */
char temp_name[TEMP_NAME_LENGTH]; /* name of temp file */
#endif
#endif
} backing_store_info;
/*
* Initial opening of a backing-store object. This must fill in the
* read/write/close pointers in the object. The read/write routines
* may take an error exit if the specified maximum file size is exceeded.
* (If jpeg_mem_available always returns a large value, this routine can
* just take an error exit.)
*/
EXTERN(void) jpeg_open_backing_store JPP((j_common_ptr cinfo,
backing_store_ptr info,
long total_bytes_needed));
/*
* These routines take care of any system-dependent initialization and
* cleanup required. jpeg_mem_init will be called before anything is
* allocated (and, therefore, nothing in cinfo is of use except the error
* manager pointer). It should return a suitable default value for
* max_memory_to_use; this may subsequently be overridden by the surrounding
* application. (Note that max_memory_to_use is only important if
* jpeg_mem_available chooses to consult it ... no one else will.)
* jpeg_mem_term may assume that all requested memory has been freed and that
* all opened backing-store objects have been closed.
*/
EXTERN(long) jpeg_mem_init JPP((j_common_ptr cinfo));
EXTERN(void) jpeg_mem_term JPP((j_common_ptr cinfo));
--- NEW FILE: jddctmgr.c ---
/*
* jddctmgr.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains the inverse-DCT management logic.
* This code selects a particular IDCT implementation to be used,
* and it performs related housekeeping chores. No code in this file
* is executed per IDCT step, only during output pass setup.
*
* Note that the IDCT routines are responsible for performing coefficient
* dequantization as well as the IDCT proper. This module sets up the
* dequantization multiplier table needed by the IDCT routine.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
/*
* The decompressor input side (jdinput.c) saves away the appropriate
* quantization table for each component at the start of the first scan
* involving that component. (This is necessary in order to correctly
* decode files that reuse Q-table slots.)
* When we are ready to make an output pass, the saved Q-table is converted
* to a multiplier table that will actually be used by the IDCT routine.
* The multiplier table contents are IDCT-method-dependent. To support
* application changes in IDCT method between scans, we can remake the
* multiplier tables if necessary.
* In buffered-image mode, the first output pass may occur before any data
* has been seen for some components, and thus before their Q-tables have
* been saved away. To handle this case, multiplier tables are preset
* to zeroes; the result of the IDCT will be a neutral gray level.
*/
/* Private subobject for this module */
typedef struct {
struct jpeg_inverse_dct pub; /* public fields */
/* This array contains the IDCT method code that each multiplier table
* is currently set up for, or -1 if it's not yet set up.
* The actual multiplier tables are pointed to by dct_table in the
* per-component comp_info structures.
*/
int cur_method[MAX_COMPONENTS];
} my_idct_controller;
typedef my_idct_controller * my_idct_ptr;
/* Allocated multiplier tables: big enough for any supported variant */
typedef union {
ISLOW_MULT_TYPE islow_array[DCTSIZE2];
#ifdef DCT_IFAST_SUPPORTED
IFAST_MULT_TYPE ifast_array[DCTSIZE2];
#endif
#ifdef DCT_FLOAT_SUPPORTED
FLOAT_MULT_TYPE float_array[DCTSIZE2];
#endif
} multiplier_table;
/* The current scaled-IDCT routines require ISLOW-style multiplier tables,
* so be sure to compile that code if either ISLOW or SCALING is requested.
*/
#ifdef DCT_ISLOW_SUPPORTED
#define PROVIDE_ISLOW_TABLES
#else
#ifdef IDCT_SCALING_SUPPORTED
#define PROVIDE_ISLOW_TABLES
#endif
#endif
/*
* Prepare for an output pass.
* Here we select the proper IDCT routine for each component and build
* a matching multiplier table.
*/
METHODDEF(void)
start_pass (j_decompress_ptr cinfo)
{
my_idct_ptr idct = (my_idct_ptr) cinfo->idct;
int ci, i;
jpeg_component_info *compptr;
int method = 0;
inverse_DCT_method_ptr method_ptr = NULL;
JQUANT_TBL * qtbl;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Select the proper IDCT routine for this component's scaling */
switch (compptr->DCT_scaled_size) {
#ifdef IDCT_SCALING_SUPPORTED
case 1:
method_ptr = jpeg_idct_1x1;
method = JDCT_ISLOW; /* jidctred uses islow-style table */
break;
case 2:
method_ptr = jpeg_idct_2x2;
method = JDCT_ISLOW; /* jidctred uses islow-style table */
break;
case 4:
method_ptr = jpeg_idct_4x4;
method = JDCT_ISLOW; /* jidctred uses islow-style table */
break;
#endif
case DCTSIZE:
switch (cinfo->dct_method) {
#ifdef DCT_ISLOW_SUPPORTED
case JDCT_ISLOW:
method_ptr = jpeg_idct_islow;
method = JDCT_ISLOW;
break;
#endif
#ifdef DCT_IFAST_SUPPORTED
case JDCT_IFAST:
method_ptr = jpeg_idct_ifast;
method = JDCT_IFAST;
break;
#endif
#ifdef DCT_FLOAT_SUPPORTED
case JDCT_FLOAT:
method_ptr = jpeg_idct_float;
method = JDCT_FLOAT;
break;
#endif
default:
ERREXIT(cinfo, JERR_NOT_COMPILED);
break;
}
break;
default:
ERREXIT1(cinfo, JERR_BAD_DCTSIZE, compptr->DCT_scaled_size);
break;
}
idct->pub.inverse_DCT[ci] = method_ptr;
/* Create multiplier table from quant table.
* However, we can skip this if the component is uninteresting
* or if we already built the table. Also, if no quant table
* has yet been saved for the component, we leave the
* multiplier table all-zero; we'll be reading zeroes from the
* coefficient controller's buffer anyway.
*/
if (! compptr->component_needed || idct->cur_method[ci] == method)
continue;
qtbl = compptr->quant_table;
if (qtbl == NULL) /* happens if no data yet for component */
continue;
idct->cur_method[ci] = method;
switch (method) {
#ifdef PROVIDE_ISLOW_TABLES
case JDCT_ISLOW:
{
/* For LL&M IDCT method, multipliers are equal to raw quantization
* coefficients, but are stored as ints to ensure access efficiency.
*/
ISLOW_MULT_TYPE * ismtbl = (ISLOW_MULT_TYPE *) compptr->dct_table;
for (i = 0; i < DCTSIZE2; i++) {
ismtbl[i] = (ISLOW_MULT_TYPE) qtbl->quantval[i];
}
}
break;
#endif
#ifdef DCT_IFAST_SUPPORTED
case JDCT_IFAST:
{
/* For AA&N IDCT method, multipliers are equal to quantization
* coefficients scaled by scalefactor[row]*scalefactor[col], where
* scalefactor[0] = 1
* scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
* For integer operation, the multiplier table is to be scaled by
* IFAST_SCALE_BITS.
*/
IFAST_MULT_TYPE * ifmtbl = (IFAST_MULT_TYPE *) compptr->dct_table;
#define CONST_BITS 14
static const INT16 aanscales[DCTSIZE2] = {
/* precomputed values scaled up by 14 bits */
16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
22725, 31521, 29692, 26722, 22725, 17855, 12299, 6270,
21407, 29692, 27969, 25172, 21407, 16819, 11585, 5906,
19266, 26722, 25172, 22654, 19266, 15137, 10426, 5315,
16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
12873, 17855, 16819, 15137, 12873, 10114, 6967, 3552,
8867, 12299, 11585, 10426, 8867, 6967, 4799, 2446,
4520, 6270, 5906, 5315, 4520, 3552, 2446, 1247
};
SHIFT_TEMPS
for (i = 0; i < DCTSIZE2; i++) {
ifmtbl[i] = (IFAST_MULT_TYPE)
DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
(INT32) aanscales[i]),
CONST_BITS-IFAST_SCALE_BITS);
}
}
break;
#endif
#ifdef DCT_FLOAT_SUPPORTED
case JDCT_FLOAT:
{
/* For float AA&N IDCT method, multipliers are equal to quantization
* coefficients scaled by scalefactor[row]*scalefactor[col], where
* scalefactor[0] = 1
* scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
*/
FLOAT_MULT_TYPE * fmtbl = (FLOAT_MULT_TYPE *) compptr->dct_table;
int row, col;
static const double aanscalefactor[DCTSIZE] = {
1.0, 1.387039845, 1.306562965, 1.175875602,
1.0, 0.785694958, 0.541196100, 0.275899379
};
i = 0;
for (row = 0; row < DCTSIZE; row++) {
for (col = 0; col < DCTSIZE; col++) {
fmtbl[i] = (FLOAT_MULT_TYPE)
((double) qtbl->quantval[i] *
aanscalefactor[row] * aanscalefactor[col]);
i++;
}
}
}
break;
#endif
default:
ERREXIT(cinfo, JERR_NOT_COMPILED);
break;
}
}
}
/*
* Initialize IDCT manager.
*/
GLOBAL(void)
jinit_inverse_dct (j_decompress_ptr cinfo)
{
my_idct_ptr idct;
int ci;
jpeg_component_info *compptr;
idct = (my_idct_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_idct_controller));
cinfo->idct = (struct jpeg_inverse_dct *) idct;
idct->pub.start_pass = start_pass;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Allocate and pre-zero a multiplier table for each component */
compptr->dct_table =
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(multiplier_table));
MEMZERO(compptr->dct_table, SIZEOF(multiplier_table));
/* Mark multiplier table not yet set up for any method */
idct->cur_method[ci] = -1;
}
}
--- NEW FILE: jdinput.c ---
/*
* jdinput.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains input control logic for the JPEG decompressor.
* These routines are concerned with controlling the decompressor's input
* processing (marker reading and coefficient decoding). The actual input
* reading is done in jdmarker.c, jdhuff.c, and jdphuff.c.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Private state */
typedef struct {
struct jpeg_input_controller pub; /* public fields */
boolean inheaders; /* TRUE until first SOS is reached */
} my_input_controller;
typedef my_input_controller * my_inputctl_ptr;
/* Forward declarations */
METHODDEF(int) consume_markers JPP((j_decompress_ptr cinfo));
/*
* Routines to calculate various quantities related to the size of the image.
*/
LOCAL(void)
initial_setup (j_decompress_ptr cinfo)
/* Called once, when first SOS marker is reached */
{
int ci;
jpeg_component_info *compptr;
/* Make sure image isn't bigger than I can handle */
if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
(long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
/* For now, precision must match compiled-in value... */
if (cinfo->data_precision != BITS_IN_JSAMPLE)
ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
/* Check that number of components won't exceed internal array sizes */
if (cinfo->num_components > MAX_COMPONENTS)
ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
MAX_COMPONENTS);
/* Compute maximum sampling factors; check factor validity */
cinfo->max_h_samp_factor = 1;
cinfo->max_v_samp_factor = 1;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
ERREXIT(cinfo, JERR_BAD_SAMPLING);
cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
compptr->h_samp_factor);
cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
compptr->v_samp_factor);
}
/* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE.
* In the full decompressor, this will be overridden by jdmaster.c;
* but in the transcoder, jdmaster.c is not used, so we must do it here.
*/
cinfo->min_DCT_scaled_size = DCTSIZE;
/* Compute dimensions of components */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
compptr->DCT_scaled_size = DCTSIZE;
/* Size in DCT blocks */
compptr->width_in_blocks = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
(long) (cinfo->max_h_samp_factor * DCTSIZE));
compptr->height_in_blocks = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
(long) (cinfo->max_v_samp_factor * DCTSIZE));
/* downsampled_width and downsampled_height will also be overridden by
* jdmaster.c if we are doing full decompression. The transcoder library
* doesn't use these values, but the calling application might.
*/
/* Size in samples */
compptr->downsampled_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
(long) cinfo->max_h_samp_factor);
compptr->downsampled_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
(long) cinfo->max_v_samp_factor);
/* Mark component needed, until color conversion says otherwise */
compptr->component_needed = TRUE;
/* Mark no quantization table yet saved for component */
compptr->quant_table = NULL;
}
/* Compute number of fully interleaved MCU rows. */
cinfo->total_iMCU_rows = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height,
(long) (cinfo->max_v_samp_factor*DCTSIZE));
/* Decide whether file contains multiple scans */
if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode)
cinfo->inputctl->has_multiple_scans = TRUE;
else
cinfo->inputctl->has_multiple_scans = FALSE;
}
LOCAL(void)
per_scan_setup (j_decompress_ptr cinfo)
/* Do computations that are needed before processing a JPEG scan */
/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */
{
int ci, mcublks, tmp;
jpeg_component_info *compptr;
if (cinfo->comps_in_scan == 1) {
/* Noninterleaved (single-component) scan */
compptr = cinfo->cur_comp_info[0];
/* Overall image size in MCUs */
cinfo->MCUs_per_row = compptr->width_in_blocks;
cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
/* For noninterleaved scan, always one block per MCU */
compptr->MCU_width = 1;
compptr->MCU_height = 1;
compptr->MCU_blocks = 1;
compptr->MCU_sample_width = compptr->DCT_scaled_size;
compptr->last_col_width = 1;
/* For noninterleaved scans, it is convenient to define last_row_height
* as the number of block rows present in the last iMCU row.
*/
tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
if (tmp == 0) tmp = compptr->v_samp_factor;
compptr->last_row_height = tmp;
/* Prepare array describing MCU composition */
cinfo->blocks_in_MCU = 1;
cinfo->MCU_membership[0] = 0;
} else {
/* Interleaved (multi-component) scan */
if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
MAX_COMPS_IN_SCAN);
/* Overall image size in MCUs */
cinfo->MCUs_per_row = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width,
(long) (cinfo->max_h_samp_factor*DCTSIZE));
cinfo->MCU_rows_in_scan = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height,
(long) (cinfo->max_v_samp_factor*DCTSIZE));
cinfo->blocks_in_MCU = 0;
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
/* Sampling factors give # of blocks of component in each MCU */
compptr->MCU_width = compptr->h_samp_factor;
compptr->MCU_height = compptr->v_samp_factor;
compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size;
/* Figure number of non-dummy blocks in last MCU column & row */
tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
if (tmp == 0) tmp = compptr->MCU_width;
compptr->last_col_width = tmp;
tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
if (tmp == 0) tmp = compptr->MCU_height;
compptr->last_row_height = tmp;
/* Prepare array describing MCU composition */
mcublks = compptr->MCU_blocks;
if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU)
ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
while (mcublks-- > 0) {
cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
}
}
}
}
/*
* Save away a copy of the Q-table referenced by each component present
* in the current scan, unless already saved during a prior scan.
*
* In a multiple-scan JPEG file, the encoder could assign different components
* the same Q-table slot number, but change table definitions between scans
* so that each component uses a different Q-table. (The IJG encoder is not
* currently capable of doing this, but other encoders might.) Since we want
* to be able to dequantize all the components at the end of the file, this
* means that we have to save away the table actually used for each component.
* We do this by copying the table at the start of the first scan containing
* the component.
* The JPEG spec prohibits the encoder from changing the contents of a Q-table
* slot between scans of a component using that slot. If the encoder does so
* anyway, this decoder will simply use the Q-table values that were current
* at the start of the first scan for the component.
*
* The decompressor output side looks only at the saved quant tables,
* not at the current Q-table slots.
*/
LOCAL(void)
latch_quant_tables (j_decompress_ptr cinfo)
{
int ci, qtblno;
jpeg_component_info *compptr;
JQUANT_TBL * qtbl;
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
/* No work if we already saved Q-table for this component */
if (compptr->quant_table != NULL)
continue;
/* Make sure specified quantization table is present */
qtblno = compptr->quant_tbl_no;
if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS ||
cinfo->quant_tbl_ptrs[qtblno] == NULL)
ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno);
/* OK, save away the quantization table */
qtbl = (JQUANT_TBL *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(JQUANT_TBL));
MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL));
compptr->quant_table = qtbl;
}
}
/*
* Initialize the input modules to read a scan of compressed data.
* The first call to this is done by jdmaster.c after initializing
* the entire decompressor (during jpeg_start_decompress).
* Subsequent calls come from consume_markers, below.
*/
METHODDEF(void)
start_input_pass (j_decompress_ptr cinfo)
{
per_scan_setup(cinfo);
latch_quant_tables(cinfo);
(*cinfo->entropy->start_pass) (cinfo);
(*cinfo->coef->start_input_pass) (cinfo);
cinfo->inputctl->consume_input = cinfo->coef->consume_data;
}
/*
* Finish up after inputting a compressed-data scan.
* This is called by the coefficient controller after it's read all
* the expected data of the scan.
*/
METHODDEF(void)
finish_input_pass (j_decompress_ptr cinfo)
{
cinfo->inputctl->consume_input = consume_markers;
}
/*
* Read JPEG markers before, between, or after compressed-data scans.
* Change state as necessary when a new scan is reached.
* Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
*
* The consume_input method pointer points either here or to the
* coefficient controller's consume_data routine, depending on whether
* we are reading a compressed data segment or inter-segment markers.
*/
METHODDEF(int)
consume_markers (j_decompress_ptr cinfo)
{
my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
int val;
if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */
return JPEG_REACHED_EOI;
val = (*cinfo->marker->read_markers) (cinfo);
switch (val) {
case JPEG_REACHED_SOS: /* Found SOS */
if (inputctl->inheaders) { /* 1st SOS */
initial_setup(cinfo);
inputctl->inheaders = FALSE;
/* Note: start_input_pass must be called by jdmaster.c
* before any more input can be consumed. jdapimin.c is
* responsible for enforcing this sequencing.
*/
} else { /* 2nd or later SOS marker */
if (! inputctl->pub.has_multiple_scans)
ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */
start_input_pass(cinfo);
}
break;
case JPEG_REACHED_EOI: /* Found EOI */
inputctl->pub.eoi_reached = TRUE;
if (inputctl->inheaders) { /* Tables-only datastream, apparently */
if (cinfo->marker->saw_SOF)
ERREXIT(cinfo, JERR_SOF_NO_SOS);
} else {
/* Prevent infinite loop in coef ctlr's decompress_data routine
* if user set output_scan_number larger than number of scans.
*/
if (cinfo->output_scan_number > cinfo->input_scan_number)
cinfo->output_scan_number = cinfo->input_scan_number;
}
break;
case JPEG_SUSPENDED:
break;
}
return val;
}
/*
* Reset state to begin a fresh datastream.
*/
METHODDEF(void)
reset_input_controller (j_decompress_ptr cinfo)
{
my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
inputctl->pub.consume_input = consume_markers;
inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
inputctl->pub.eoi_reached = FALSE;
inputctl->inheaders = TRUE;
/* Reset other modules */
(*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
(*cinfo->marker->reset_marker_reader) (cinfo);
/* Reset progression state -- would be cleaner if entropy decoder did this */
cinfo->coef_bits = NULL;
}
/*
* Initialize the input controller module.
* This is called only once, when the decompression object is created.
*/
GLOBAL(void)
jinit_input_controller (j_decompress_ptr cinfo)
{
my_inputctl_ptr inputctl;
/* Create subobject in permanent pool */
inputctl = (my_inputctl_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
SIZEOF(my_input_controller));
cinfo->inputctl = (struct jpeg_input_controller *) inputctl;
/* Initialize method pointers */
inputctl->pub.consume_input = consume_markers;
inputctl->pub.reset_input_controller = reset_input_controller;
inputctl->pub.start_input_pass = start_input_pass;
inputctl->pub.finish_input_pass = finish_input_pass;
/* Initialize state: can't use reset_input_controller since we don't
* want to try to reset other modules yet.
*/
inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
inputctl->pub.eoi_reached = FALSE;
inputctl->inheaders = TRUE;
}
--- NEW FILE: README ---
The Independent JPEG Group's JPEG software
==========================================
README for release 6b of 27-Mar-1998
====================================
This distribution contains the sixth public release of the Independent JPEG
Group's free JPEG software. You are welcome to redistribute this software and
to use it for any purpose, subject to the conditions under LEGAL ISSUES, below.
Serious users of this software (particularly those incorporating it into
larger programs) should contact IJG at jpeg-info at uunet.uu.net to be added to
our electronic mailing list. Mailing list members are notified of updates
and have a chance to participate in technical discussions, etc.
This software is the work of Tom Lane, Philip Gladstone, Jim Boucher,
Lee Crocker, Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi,
Guido Vollbeding, Ge' Weijers, and other members of the Independent JPEG
Group.
IJG is not affiliated with the official ISO JPEG standards committee.
DOCUMENTATION ROADMAP
=====================
This file contains the following sections:
OVERVIEW General description of JPEG and the IJG software.
LEGAL ISSUES Copyright, lack of warranty, terms of distribution.
REFERENCES Where to learn more about JPEG.
ARCHIVE LOCATIONS Where to find newer versions of this software.
RELATED SOFTWARE Other stuff you should get.
FILE FORMAT WARS Software *not* to get.
TO DO Plans for future IJG releases.
Other documentation files in the distribution are:
User documentation:
install.doc How to configure and install the IJG software.
usage.doc Usage instructions for cjpeg, djpeg, jpegtran,
rdjpgcom, and wrjpgcom.
*.1 Unix-style man pages for programs (same info as usage.doc).
wizard.doc Advanced usage instructions for JPEG wizards only.
change.log Version-to-version change highlights.
Programmer and internal documentation:
libjpeg.doc How to use the JPEG library in your own programs.
example.c Sample code for calling the JPEG library.
structure.doc Overview of the JPEG library's internal structure.
filelist.doc Road map of IJG files.
coderules.doc Coding style rules --- please read if you contribute code.
Please read at least the files install.doc and usage.doc. Useful information
can also be found in the JPEG FAQ (Frequently Asked Questions) article. See
ARCHIVE LOCATIONS below to find out where to obtain the FAQ article.
If you want to understand how the JPEG code works, we suggest reading one or
more of the REFERENCES, then looking at the documentation files (in roughly
the order listed) before diving into the code.
OVERVIEW
========
This package contains C software to implement JPEG image compression and
decompression. JPEG (pronounced "jay-peg") is a standardized compression
method for full-color and gray-scale images. JPEG is intended for compressing
"real-world" scenes; line drawings, cartoons and other non-realistic images
are not its strong suit. JPEG is lossy, meaning that the output image is not
exactly identical to the input image. Hence you must not use JPEG if you
have to have identical output bits. However, on typical photographic images,
very good compression levels can be obtained with no visible change, and
remarkably high compression levels are possible if you can tolerate a
low-quality image. For more details, see the references, or just experiment
with various compression settings.
This software implements JPEG baseline, extended-sequential, and progressive
compression processes. Provision is made for supporting all variants of these
processes, although some uncommon parameter settings aren't implemented yet.
For legal reasons, we are not distributing code for the arithmetic-coding
variants of JPEG; see LEGAL ISSUES. We have made no provision for supporting
the hierarchical or lossless processes defined in the standard.
We provide a set of library routines for reading and writing JPEG image files,
plus two sample applications "cjpeg" and "djpeg", which use the library to
perform conversion between JPEG and some other popular image file formats.
The library is intended to be reused in other applications.
In order to support file conversion and viewing software, we have included
considerable functionality beyond the bare JPEG coding/decoding capability;
for example, the color quantization modules are not strictly part of JPEG
decoding, but they are essential for output to colormapped file formats or
colormapped displays. These extra functions can be compiled out of the
library if not required for a particular application. We have also included
"jpegtran", a utility for lossless transcoding between different JPEG
processes, and "rdjpgcom" and "wrjpgcom", two simple applications for
inserting and extracting textual comments in JFIF files.
The emphasis in designing this software has been on achieving portability and
flexibility, while also making it fast enough to be useful. In particular,
the software is not intended to be read as a tutorial on JPEG. (See the
REFERENCES section for introductory material.) Rather, it is intended to
be reliable, portable, industrial-strength code. We do not claim to have
achieved that goal in every aspect of the software, but we strive for it.
We welcome the use of this software as a component of commercial products.
No royalty is required, but we do ask for an acknowledgement in product
documentation, as described under LEGAL ISSUES.
LEGAL ISSUES
============
In plain English:
1. We don't promise that this software works. (But if you find any bugs,
please let us know!)
2. You can use this software for whatever you want. You don't have to pay us.
3. You may not pretend that you wrote this software. If you use it in a
program, you must acknowledge somewhere in your documentation that
you've used the IJG code.
In legalese:
The authors make NO WARRANTY or representation, either express or implied,
with respect to this software, its quality, accuracy, merchantability, or
fitness for a particular purpose. This software is provided "AS IS", and you,
its user, assume the entire risk as to its quality and accuracy.
This software is copyright (C) 1991-1998, Thomas G. Lane.
All Rights Reserved except as specified below.
Permission is hereby granted to use, copy, modify, and distribute this
software (or portions thereof) for any purpose, without fee, subject to these
conditions:
(1) If any part of the source code for this software is distributed, then this
README file must be included, with this copyright and no-warranty notice
unaltered; and any additions, deletions, or changes to the original files
must be clearly indicated in accompanying documentation.
(2) If only executable code is distributed, then the accompanying
documentation must state that "this software is based in part on the work of
the Independent JPEG Group".
(3) Permission for use of this software is granted only if the user accepts
full responsibility for any undesirable consequences; the authors accept
NO LIABILITY for damages of any kind.
These conditions apply to any software derived from or based on the IJG code,
not just to the unmodified library. If you use our work, you ought to
acknowledge us.
Permission is NOT granted for the use of any IJG author's name or company name
in advertising or publicity relating to this software or products derived from
it. This software may be referred to only as "the Independent JPEG Group's
software".
We specifically permit and encourage the use of this software as the basis of
commercial products, provided that all warranty or liability claims are
assumed by the product vendor.
ansi2knr.c is included in this distribution by permission of L. Peter Deutsch,
sole proprietor of its copyright holder, Aladdin Enterprises of Menlo Park, CA.
ansi2knr.c is NOT covered by the above copyright and conditions, but instead
by the usual distribution terms of the Free Software Foundation; principally,
that you must include source code if you redistribute it. (See the file
ansi2knr.c for full details.) However, since ansi2knr.c is not needed as part
of any program generated from the IJG code, this does not limit you more than
the foregoing paragraphs do.
The Unix configuration script "configure" was produced with GNU Autoconf.
It is copyright by the Free Software Foundation but is freely distributable.
The same holds for its supporting scripts (config.guess, config.sub,
ltconfig, ltmain.sh). Another support script, install-sh, is copyright
by M.I.T. but is also freely distributable.
It appears that the arithmetic coding option of the JPEG spec is covered by
patents owned by IBM, AT&T, and Mitsubishi. Hence arithmetic coding cannot
legally be used without obtaining one or more licenses. For this reason,
support for arithmetic coding has been removed from the free JPEG software.
(Since arithmetic coding provides only a marginal gain over the unpatented
Huffman mode, it is unlikely that very many implementations will support it.)
So far as we are aware, there are no patent restrictions on the remaining
code.
The IJG distribution formerly included code to read and write GIF files.
To avoid entanglement with the Unisys LZW patent, GIF reading support has
been removed altogether, and the GIF writer has been simplified to produce
"uncompressed GIFs". This technique does not use the LZW algorithm; the
resulting GIF files are larger than usual, but are readable by all standard
GIF decoders.
We are required to state that
"The Graphics Interchange Format(c) is the Copyright property of
CompuServe Incorporated. GIF(sm) is a Service Mark property of
CompuServe Incorporated."
REFERENCES
==========
We highly recommend reading one or more of these references before trying to
understand the innards of the JPEG software.
The best short technical introduction to the JPEG compression algorithm is
Wallace, Gregory K. "The JPEG Still Picture Compression Standard",
Communications of the ACM, April 1991 (vol. 34 no. 4), pp. 30-44.
(Adjacent articles in that issue discuss MPEG motion picture compression,
applications of JPEG, and related topics.) If you don't have the CACM issue
handy, a PostScript file containing a revised version of Wallace's article is
available at ftp://ftp.uu.net/graphics/jpeg/wallace.ps.gz. The file (actually
a preprint for an article that appeared in IEEE Trans. Consumer Electronics)
omits the sample images that appeared in CACM, but it includes corrections
and some added material. Note: the Wallace article is copyright ACM and IEEE,
and it may not be used for commercial purposes.
A somewhat less technical, more leisurely introduction to JPEG can be found in
"The Data Compression Book" by Mark Nelson and Jean-loup Gailly, published by
M&T Books (New York), 2nd ed. 1996, ISBN 1-55851-434-1. This book provides
good explanations and example C code for a multitude of compression methods
including JPEG. It is an excellent source if you are comfortable reading C
code but don't know much about data compression in general. The book's JPEG
sample code is far from industrial-strength, but when you are ready to look
at a full implementation, you've got one here...
The best full description of JPEG is the textbook "JPEG Still Image Data
Compression Standard" by William B. Pennebaker and Joan L. Mitchell, published
by Van Nostrand Reinhold, 1993, ISBN 0-442-01272-1. Price US$59.95, 638 pp.
The book includes the complete text of the ISO JPEG standards (DIS 10918-1
and draft DIS 10918-2). This is by far the most complete exposition of JPEG
in existence, and we highly recommend it.
The JPEG standard itself is not available electronically; you must order a
paper copy through ISO or ITU. (Unless you feel a need to own a certified
official copy, we recommend buying the Pennebaker and Mitchell book instead;
it's much cheaper and includes a great deal of useful explanatory material.)
In the USA, copies of the standard may be ordered from ANSI Sales at (212)
642-4900, or from Global Engineering Documents at (800) 854-7179. (ANSI
doesn't take credit card orders, but Global does.) It's not cheap: as of
1992, ANSI was charging $95 for Part 1 and $47 for Part 2, plus 7%
shipping/handling. The standard is divided into two parts, Part 1 being the
actual specification, while Part 2 covers compliance testing methods. Part 1
is titled "Digital Compression and Coding of Continuous-tone Still Images,
Part 1: Requirements and guidelines" and has document numbers ISO/IEC IS
10918-1, ITU-T T.81. Part 2 is titled "Digital Compression and Coding of
Continuous-tone Still Images, Part 2: Compliance testing" and has document
numbers ISO/IEC IS 10918-2, ITU-T T.83.
Some extensions to the original JPEG standard are defined in JPEG Part 3,
a newer ISO standard numbered ISO/IEC IS 10918-3 and ITU-T T.84. IJG
currently does not support any Part 3 extensions.
The JPEG standard does not specify all details of an interchangeable file
format. For the omitted details we follow the "JFIF" conventions, revision
1.02. A copy of the JFIF spec is available from:
Literature Department
C-Cube Microsystems, Inc.
1778 McCarthy Blvd.
Milpitas, CA 95035
phone (408) 944-6300, fax (408) 944-6314
A PostScript version of this document is available by FTP at
ftp://ftp.uu.net/graphics/jpeg/jfif.ps.gz. There is also a plain text
version at ftp://ftp.uu.net/graphics/jpeg/jfif.txt.gz, but it is missing
the figures.
The TIFF 6.0 file format specification can be obtained by FTP from
ftp://ftp.sgi.com/graphics/tiff/TIFF6.ps.gz. The JPEG incorporation scheme
found in the TIFF 6.0 spec of 3-June-92 has a number of serious problems.
IJG does not recommend use of the TIFF 6.0 design (TIFF Compression tag 6).
Instead, we recommend the JPEG design proposed by TIFF Technical Note #2
(Compression tag 7). Copies of this Note can be obtained from ftp.sgi.com or
from ftp://ftp.uu.net/graphics/jpeg/. It is expected that the next revision
of the TIFF spec will replace the 6.0 JPEG design with the Note's design.
Although IJG's own code does not support TIFF/JPEG, the free libtiff library
uses our library to implement TIFF/JPEG per the Note. libtiff is available
from ftp://ftp.sgi.com/graphics/tiff/.
ARCHIVE LOCATIONS
=================
The "official" archive site for this software is ftp.uu.net (Internet
address 192.48.96.9). The most recent released version can always be found
there in directory graphics/jpeg. This particular version will be archived
as ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz. If you don't have
direct Internet access, UUNET's archives are also available via UUCP; contact
help at uunet.uu.net for information on retrieving files that way.
Numerous Internet sites maintain copies of the UUNET files. However, only
ftp.uu.net is guaranteed to have the latest official version.
You can also obtain this software in DOS-compatible "zip" archive format from
the SimTel archives (ftp://ftp.simtel.net/pub/simtelnet/msdos/graphics/), or
on CompuServe in the Graphics Support forum (GO CIS:GRAPHSUP), library 12
"JPEG Tools". Again, these versions may sometimes lag behind the ftp.uu.net
release.
The JPEG FAQ (Frequently Asked Questions) article is a useful source of
general information about JPEG. It is updated constantly and therefore is
not included in this distribution. The FAQ is posted every two weeks to
Usenet newsgroups comp.graphics.misc, news.answers, and other groups.
It is available on the World Wide Web at http://www.faqs.org/faqs/jpeg-faq/
and other news.answers archive sites, including the official news.answers
archive at rtfm.mit.edu: ftp://rtfm.mit.edu/pub/usenet/news.answers/jpeg-faq/.
If you don't have Web or FTP access, send e-mail to mail-server at rtfm.mit.edu
with body
send usenet/news.answers/jpeg-faq/part1
send usenet/news.answers/jpeg-faq/part2
RELATED SOFTWARE
================
Numerous viewing and image manipulation programs now support JPEG. (Quite a
few of them use this library to do so.) The JPEG FAQ described above lists
some of the more popular free and shareware viewers, and tells where to
obtain them on Internet.
If you are on a Unix machine, we highly recommend Jef Poskanzer's free
PBMPLUS software, which provides many useful operations on PPM-format image
files. In particular, it can convert PPM images to and from a wide range of
other formats, thus making cjpeg/djpeg considerably more useful. The latest
version is distributed by the NetPBM group, and is available from numerous
sites, notably ftp://wuarchive.wustl.edu/graphics/graphics/packages/NetPBM/.
Unfortunately PBMPLUS/NETPBM is not nearly as portable as the IJG software is;
you are likely to have difficulty making it work on any non-Unix machine.
A different free JPEG implementation, written by the PVRG group at Stanford,
is available from ftp://havefun.stanford.edu/pub/jpeg/. This program
is designed for research and experimentation rather than production use;
it is slower, harder to use, and less portable than the IJG code, but it
is easier to read and modify. Also, the PVRG code supports lossless JPEG,
which we do not. (On the other hand, it doesn't do progressive JPEG.)
FILE FORMAT WARS
================
Some JPEG programs produce files that are not compatible with our library.
The root of the problem is that the ISO JPEG committee failed to specify a
concrete file format. Some vendors "filled in the blanks" on their own,
creating proprietary formats that no one else could read. (For example, none
of the early commercial JPEG implementations for the Macintosh were able to
exchange compressed files.)
The file format we have adopted is called JFIF (see REFERENCES). This format
has been agreed to by a number of major commercial JPEG vendors, and it has
become the de facto standard. JFIF is a minimal or "low end" representation.
We recommend the use of TIFF/JPEG (TIFF revision 6.0 as modified by TIFF
Technical Note #2) for "high end" applications that need to record a lot of
additional data about an image. TIFF/JPEG is fairly new and not yet widely
supported, unfortunately.
The upcoming JPEG Part 3 standard defines a file format called SPIFF.
SPIFF is interoperable with JFIF, in the sense that most JFIF decoders should
be able to read the most common variant of SPIFF. SPIFF has some technical
advantages over JFIF, but its major claim to fame is simply that it is an
official standard rather than an informal one. At this point it is unclear
whether SPIFF will supersede JFIF or whether JFIF will remain the de-facto
standard. IJG intends to support SPIFF once the standard is frozen, but we
have not decided whether it should become our default output format or not.
(In any case, our decoder will remain capable of reading JFIF indefinitely.)
Various proprietary file formats incorporating JPEG compression also exist.
We have little or no sympathy for the existence of these formats. Indeed,
one of the original reasons for developing this free software was to help
force convergence on common, open format standards for JPEG files. Don't
use a proprietary file format!
TO DO
=====
The major thrust for v7 will probably be improvement of visual quality.
The current method for scaling the quantization tables is known not to be
very good at low Q values. We also intend to investigate block boundary
smoothing, "poor man's variable quantization", and other means of improving
quality-vs-file-size performance without sacrificing compatibility.
In future versions, we are considering supporting some of the upcoming JPEG
Part 3 extensions --- principally, variable quantization and the SPIFF file
format.
As always, speeding things up is of great interest.
Please send bug reports, offers of help, etc. to jpeg-info at uunet.uu.net.
--- NEW FILE: Makefile ---
# Generated automatically from makefile.cfg by configure.
# Makefile for Independent JPEG Group's software
# makefile.cfg is edited by configure to produce a custom Makefile.
# Read installation instructions before saying "make" !!
# For compiling with source and object files in different directories.
srcdir = .
# Where to install the programs and man pages.
prefix = /usr/local
exec_prefix = ${prefix}
bindir = $(exec_prefix)/bin
libdir = $(exec_prefix)/lib
includedir = $(prefix)/include
binprefix =
manprefix =
manext = 1
mandir = $(prefix)/man/man$(manext)
# You may need to adjust these cc options:
CFLAGS= -O2 -I$(srcdir) $(ALLCFLAGS)
# Generally, we recommend defining any configuration symbols in jconfig.h,
# NOT via -D switches here.
# However, any special defines for ansi2knr.c may be included here:
ANSI2KNRFLAGS=
# Link-time cc options:
LDFLAGS=
# To link any special libraries, add the necessary -l commands here.
LDLIBS=
# If using GNU libtool, LIBTOOL references it; if not, LIBTOOL is empty.
LIBTOOL =
# $(O) expands to "lo" if using libtool, plain "o" if not.
# Similarly, $(A) expands to "la" or "a".
O = o
A = a
# Library version ID; libtool uses this for the shared library version number.
# Note: we suggest this match the macro of the same name in jpeglib.h.
JPEG_LIB_VERSION = 62
# Put here the object file name for the correct system-dependent memory
# manager file. For Unix this is usually jmemnobs.o, but you may want
# to use jmemansi.o or jmemname.o if you have limited swap space.
SYSDEPMEM= jmemnobs.$(O)
# miscellaneous OS-dependent stuff
SHELL= /bin/sh
# linker
LN= $(CC)
# file deletion command
RM= rm -f
# directory creation command
MKDIR= mkdir
# library (.a) file creation command
AR= ar rc
# second step in .a creation (use "touch" if not needed)
AR2= ranlib
# installation program
INSTALL= /usr/bin/install -c
INSTALL_PROGRAM= ${INSTALL}
INSTALL_LIB= ${INSTALL} -m 644
INSTALL_DATA= ${INSTALL} -m 644
# End of configurable options.
# library object files common to compression and decompression
COMOBJECTS= jcomapi.$(O) jutils.$(O) jerror.$(O) jmemmgr.$(O) $(SYSDEPMEM)
# decompression library object files
DLIBOBJECTS= jdapimin.$(O) jdapistd.$(O) jdtrans.$(O) jdatasrc.$(O) \
jdmaster.$(O) jdinput.$(O) jdmarker.$(O) jdhuff.$(O) jdphuff.$(O) \
jdmainct.$(O) jdcoefct.$(O) jdpostct.$(O) jddctmgr.$(O) \
jidctfst.$(O) jidctflt.$(O) jidctint.$(O) jidctred.$(O) \
jdsample.$(O) jdcolor.$(O) jquant1.$(O) jquant2.$(O) jdmerge.$(O)
# These objectfiles are included in libjpeg.a
LIBOBJECTS= $(DLIBOBJECTS) $(COMOBJECTS)
all: libjpeg.$(A)
# the library:
# without libtool:
libjpeg.a: $(LIBOBJECTS)
$(RM) libjpeg.a
$(AR) libjpeg.a $(LIBOBJECTS)
$(AR2) libjpeg.a
clean:
$(RM) *.o *.lo libjpeg.a libjpeg.la
# Mistake catcher:
# GNU Make likes to know which target names are not really files to be made:
.PHONY: all install install-lib install-headers clean distclean test check
jcomapi.$(O): jcomapi.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdapimin.$(O): jdapimin.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdapistd.$(O): jdapistd.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdatadst.$(O): jdatadst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h
jdatasrc.$(O): jdatasrc.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h
jdcoefct.$(O): jdcoefct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdcolor.$(O): jdcolor.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jddctmgr.$(O): jddctmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.h
jdhuff.$(O): jdhuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdhuff.h
jdinput.$(O): jdinput.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdmainct.$(O): jdmainct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdmarker.$(O): jdmarker.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdmaster.$(O): jdmaster.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdmerge.$(O): jdmerge.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdphuff.$(O): jdphuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdhuff.h
jdpostct.$(O): jdpostct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdsample.$(O): jdsample.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jdtrans.$(O): jdtrans.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jerror.$(O): jerror.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jversion.h jerror.h
jidctflt.$(O): jidctflt.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.h
jidctfst.$(O): jidctfst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.h
jidctint.$(O): jidctint.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.h
jidctred.$(O): jidctred.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.h
jquant1.$(O): jquant1.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jquant2.$(O): jquant2.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jutils.$(O): jutils.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h
jmemmgr.$(O): jmemmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.h
jmemnobs.$(O): jmemnobs.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.h
--- NEW FILE: jmemmgr.c ---
/*
* jmemmgr.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains the JPEG system-independent memory management
* routines. This code is usable across a wide variety of machines; most
* of the system dependencies have been isolated in a separate file.
* The major functions provided here are:
* * pool-based allocation and freeing of memory;
* * policy decisions about how to divide available memory among the
* virtual arrays;
* * control logic for swapping virtual arrays between main memory and
* backing storage.
* The separate system-dependent file provides the actual backing-storage
* access code, and it contains the policy decision about how much total
* main memory to use.
[...1079 lines suppressed...]
* surrounding application may again override this value.
* If your system doesn't support getenv(), define NO_GETENV to disable
* this feature.
*/
#ifndef NO_GETENV
{ char * memenv;
if ((memenv = getenv("JPEGMEM")) != NULL) {
char ch = 'x';
if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) {
if (ch == 'm' || ch == 'M')
max_to_use *= 1000L;
mem->pub.max_memory_to_use = max_to_use * 1000L;
}
}
}
#endif
}
--- NEW FILE: jpegint.h ---
/*
* jpegint.h
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file provides common declarations for the various JPEG modules.
* These declarations are considered internal to the JPEG library; most
* applications using the library shouldn't need to include this file.
*/
/* Declarations for both compression & decompression */
typedef enum { /* Operating modes for buffer controllers */
JBUF_PASS_THRU, /* Plain stripwise operation */
/* Remaining modes require a full-image buffer to have been created */
JBUF_SAVE_SOURCE, /* Run source subobject only, save output */
JBUF_CRANK_DEST, /* Run dest subobject only, using saved data */
JBUF_SAVE_AND_PASS /* Run both subobjects, save output */
} J_BUF_MODE;
/* Values of global_state field (jdapi.c has some dependencies on ordering!) */
#define CSTATE_START 100 /* after create_compress */
#define CSTATE_SCANNING 101 /* start_compress done, write_scanlines OK */
#define CSTATE_RAW_OK 102 /* start_compress done, write_raw_data OK */
#define CSTATE_WRCOEFS 103 /* jpeg_write_coefficients done */
#define DSTATE_START 200 /* after create_decompress */
#define DSTATE_INHEADER 201 /* reading header markers, no SOS yet */
#define DSTATE_READY 202 /* found SOS, ready for start_decompress */
#define DSTATE_PRELOAD 203 /* reading multiscan file in start_decompress*/
#define DSTATE_PRESCAN 204 /* performing dummy pass for 2-pass quant */
#define DSTATE_SCANNING 205 /* start_decompress done, read_scanlines OK */
#define DSTATE_RAW_OK 206 /* start_decompress done, read_raw_data OK */
#define DSTATE_BUFIMAGE 207 /* expecting jpeg_start_output */
#define DSTATE_BUFPOST 208 /* looking for SOS/EOI in jpeg_finish_output */
#define DSTATE_RDCOEFS 209 /* reading file in jpeg_read_coefficients */
#define DSTATE_STOPPING 210 /* looking for EOI in jpeg_finish_decompress */
/* Declarations for compression modules */
/* Master control module */
struct jpeg_comp_master {
JMETHOD(void, prepare_for_pass, (j_compress_ptr cinfo));
JMETHOD(void, pass_startup, (j_compress_ptr cinfo));
JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
/* State variables made visible to other modules */
boolean call_pass_startup; /* True if pass_startup must be called */
boolean is_last_pass; /* True during last pass */
};
/* Main buffer control (downsampled-data buffer) */
struct jpeg_c_main_controller {
JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
JMETHOD(void, process_data, (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail));
};
/* Compression preprocessing (downsampling input buffer control) */
struct jpeg_c_prep_controller {
JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
JMETHOD(void, pre_process_data, (j_compress_ptr cinfo,
JSAMPARRAY input_buf,
JDIMENSION *in_row_ctr,
JDIMENSION in_rows_avail,
JSAMPIMAGE output_buf,
JDIMENSION *out_row_group_ctr,
JDIMENSION out_row_groups_avail));
};
/* Coefficient buffer control */
struct jpeg_c_coef_controller {
JMETHOD(void, start_pass, (j_compress_ptr cinfo, J_BUF_MODE pass_mode));
JMETHOD(boolean, compress_data, (j_compress_ptr cinfo,
JSAMPIMAGE input_buf));
};
/* Colorspace conversion */
struct jpeg_color_converter {
JMETHOD(void, start_pass, (j_compress_ptr cinfo));
JMETHOD(void, color_convert, (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows));
};
/* Downsampling */
struct jpeg_downsampler {
JMETHOD(void, start_pass, (j_compress_ptr cinfo));
JMETHOD(void, downsample, (j_compress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION in_row_index,
JSAMPIMAGE output_buf,
JDIMENSION out_row_group_index));
boolean need_context_rows; /* TRUE if need rows above & below */
};
/* Forward DCT (also controls coefficient quantization) */
struct jpeg_forward_dct {
JMETHOD(void, start_pass, (j_compress_ptr cinfo));
/* perhaps this should be an array??? */
JMETHOD(void, forward_DCT, (j_compress_ptr cinfo,
jpeg_component_info * compptr,
JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
JDIMENSION start_row, JDIMENSION start_col,
JDIMENSION num_blocks));
};
/* Entropy encoding */
struct jpeg_entropy_encoder {
JMETHOD(void, start_pass, (j_compress_ptr cinfo, boolean gather_statistics));
JMETHOD(boolean, encode_mcu, (j_compress_ptr cinfo, JBLOCKROW *MCU_data));
JMETHOD(void, finish_pass, (j_compress_ptr cinfo));
};
/* Marker writing */
struct jpeg_marker_writer {
JMETHOD(void, write_file_header, (j_compress_ptr cinfo));
JMETHOD(void, write_frame_header, (j_compress_ptr cinfo));
JMETHOD(void, write_scan_header, (j_compress_ptr cinfo));
JMETHOD(void, write_file_trailer, (j_compress_ptr cinfo));
JMETHOD(void, write_tables_only, (j_compress_ptr cinfo));
/* These routines are exported to allow insertion of extra markers */
/* Probably only COM and APPn markers should be written this way */
JMETHOD(void, write_marker_header, (j_compress_ptr cinfo, int marker,
unsigned int datalen));
JMETHOD(void, write_marker_byte, (j_compress_ptr cinfo, int val));
};
/* Declarations for decompression modules */
/* Master control module */
struct jpeg_decomp_master {
JMETHOD(void, prepare_for_output_pass, (j_decompress_ptr cinfo));
JMETHOD(void, finish_output_pass, (j_decompress_ptr cinfo));
/* State variables made visible to other modules */
boolean is_dummy_pass; /* True during 1st pass for 2-pass quant */
};
/* Input control module */
struct jpeg_input_controller {
JMETHOD(int, consume_input, (j_decompress_ptr cinfo));
JMETHOD(void, reset_input_controller, (j_decompress_ptr cinfo));
JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
JMETHOD(void, finish_input_pass, (j_decompress_ptr cinfo));
/* State variables made visible to other modules */
boolean has_multiple_scans; /* True if file has multiple scans */
boolean eoi_reached; /* True when EOI has been consumed */
};
/* Main buffer control (downsampled-data buffer) */
struct jpeg_d_main_controller {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
JMETHOD(void, process_data, (j_decompress_ptr cinfo,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail));
};
/* Coefficient buffer control */
struct jpeg_d_coef_controller {
JMETHOD(void, start_input_pass, (j_decompress_ptr cinfo));
JMETHOD(int, consume_data, (j_decompress_ptr cinfo));
JMETHOD(void, start_output_pass, (j_decompress_ptr cinfo));
JMETHOD(int, decompress_data, (j_decompress_ptr cinfo,
JSAMPIMAGE output_buf));
/* Pointer to array of coefficient virtual arrays, or NULL if none */
jvirt_barray_ptr *coef_arrays;
};
/* Decompression postprocessing (color quantization buffer control) */
struct jpeg_d_post_controller {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo, J_BUF_MODE pass_mode));
JMETHOD(void, post_process_data, (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf,
JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail));
};
/* Marker reading & parsing */
struct jpeg_marker_reader {
JMETHOD(void, reset_marker_reader, (j_decompress_ptr cinfo));
/* Read markers until SOS or EOI.
* Returns same codes as are defined for jpeg_consume_input:
* JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
*/
JMETHOD(int, read_markers, (j_decompress_ptr cinfo));
/* Read a restart marker --- exported for use by entropy decoder only */
jpeg_marker_parser_method read_restart_marker;
/* State of marker reader --- nominally internal, but applications
* supplying COM or APPn handlers might like to know the state.
*/
boolean saw_SOI; /* found SOI? */
boolean saw_SOF; /* found SOF? */
int next_restart_num; /* next restart number expected (0-7) */
unsigned int discarded_bytes; /* # of bytes skipped looking for a marker */
};
/* Entropy decoding */
struct jpeg_entropy_decoder {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
JMETHOD(boolean, decode_mcu, (j_decompress_ptr cinfo,
JBLOCKROW *MCU_data));
/* This is here to share code between baseline and progressive decoders; */
/* other modules probably should not use it */
boolean insufficient_data; /* set TRUE after emitting warning */
};
/* Inverse DCT (also performs dequantization) */
typedef JMETHOD(void, inverse_DCT_method_ptr,
(j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col));
struct jpeg_inverse_dct {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
/* It is useful to allow each component to have a separate IDCT method. */
inverse_DCT_method_ptr inverse_DCT[MAX_COMPONENTS];
};
/* Upsampling (note that upsampler must also call color converter) */
struct jpeg_upsampler {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
JMETHOD(void, upsample, (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf,
JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf,
JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail));
boolean need_context_rows; /* TRUE if need rows above & below */
};
/* Colorspace conversion */
struct jpeg_color_deconverter {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
JMETHOD(void, color_convert, (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows));
};
/* Color quantization or color precision reduction */
struct jpeg_color_quantizer {
JMETHOD(void, start_pass, (j_decompress_ptr cinfo, boolean is_pre_scan));
JMETHOD(void, color_quantize, (j_decompress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPARRAY output_buf,
int num_rows));
JMETHOD(void, finish_pass, (j_decompress_ptr cinfo));
JMETHOD(void, new_color_map, (j_decompress_ptr cinfo));
};
/* Miscellaneous useful macros */
#undef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#undef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
/* We assume that right shift corresponds to signed division by 2 with
* rounding towards minus infinity. This is correct for typical "arithmetic
* shift" instructions that shift in copies of the sign bit. But some
* C compilers implement >> with an unsigned shift. For these machines you
* must define RIGHT_SHIFT_IS_UNSIGNED.
* RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity.
* It is only applied with constant shift counts. SHIFT_TEMPS must be
* included in the variables of any routine using RIGHT_SHIFT.
*/
#ifdef RIGHT_SHIFT_IS_UNSIGNED
#define SHIFT_TEMPS INT32 shift_temp;
#define RIGHT_SHIFT(x,shft) \
((shift_temp = (x)) < 0 ? \
(shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \
(shift_temp >> (shft)))
#else
#define SHIFT_TEMPS
#define RIGHT_SHIFT(x,shft) ((x) >> (shft))
#endif
/* Short forms of external names for systems with brain-damaged linkers. */
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jinit_compress_master jICompress
#define jinit_c_master_control jICMaster
#define jinit_c_main_controller jICMainC
#define jinit_c_prep_controller jICPrepC
#define jinit_c_coef_controller jICCoefC
#define jinit_color_converter jICColor
#define jinit_downsampler jIDownsampler
#define jinit_forward_dct jIFDCT
#define jinit_huff_encoder jIHEncoder
#define jinit_phuff_encoder jIPHEncoder
#define jinit_marker_writer jIMWriter
#define jinit_master_decompress jIDMaster
#define jinit_d_main_controller jIDMainC
#define jinit_d_coef_controller jIDCoefC
#define jinit_d_post_controller jIDPostC
#define jinit_input_controller jIInCtlr
#define jinit_marker_reader jIMReader
#define jinit_huff_decoder jIHDecoder
#define jinit_phuff_decoder jIPHDecoder
#define jinit_inverse_dct jIIDCT
#define jinit_upsampler jIUpsampler
#define jinit_color_deconverter jIDColor
#define jinit_1pass_quantizer jI1Quant
#define jinit_2pass_quantizer jI2Quant
#define jinit_merged_upsampler jIMUpsampler
#define jinit_memory_mgr jIMemMgr
#define jdiv_round_up jDivRound
#define jround_up jRound
#define jcopy_sample_rows jCopySamples
#define jcopy_block_row jCopyBlocks
#define jzero_far jZeroFar
#define jpeg_zigzag_order jZIGTable
#define jpeg_natural_order jZAGTable
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/* Compression module initialization routines */
EXTERN(void) jinit_compress_master JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_c_master_control JPP((j_compress_ptr cinfo,
boolean transcode_only));
EXTERN(void) jinit_c_main_controller JPP((j_compress_ptr cinfo,
boolean need_full_buffer));
EXTERN(void) jinit_c_prep_controller JPP((j_compress_ptr cinfo,
boolean need_full_buffer));
EXTERN(void) jinit_c_coef_controller JPP((j_compress_ptr cinfo,
boolean need_full_buffer));
EXTERN(void) jinit_color_converter JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_downsampler JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_forward_dct JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_huff_encoder JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_phuff_encoder JPP((j_compress_ptr cinfo));
EXTERN(void) jinit_marker_writer JPP((j_compress_ptr cinfo));
/* Decompression module initialization routines */
EXTERN(void) jinit_master_decompress JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_d_main_controller JPP((j_decompress_ptr cinfo,
boolean need_full_buffer));
EXTERN(void) jinit_d_coef_controller JPP((j_decompress_ptr cinfo,
boolean need_full_buffer));
EXTERN(void) jinit_d_post_controller JPP((j_decompress_ptr cinfo,
boolean need_full_buffer));
EXTERN(void) jinit_input_controller JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_marker_reader JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_huff_decoder JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_phuff_decoder JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_inverse_dct JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_upsampler JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_color_deconverter JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_1pass_quantizer JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_2pass_quantizer JPP((j_decompress_ptr cinfo));
EXTERN(void) jinit_merged_upsampler JPP((j_decompress_ptr cinfo));
/* Memory manager initialization */
EXTERN(void) jinit_memory_mgr JPP((j_common_ptr cinfo));
/* Utility routines in jutils.c */
EXTERN(long) jdiv_round_up JPP((long a, long b));
EXTERN(long) jround_up JPP((long a, long b));
EXTERN(void) jcopy_sample_rows JPP((JSAMPARRAY input_array, int source_row,
JSAMPARRAY output_array, int dest_row,
int num_rows, JDIMENSION num_cols));
EXTERN(void) jcopy_block_row JPP((JBLOCKROW input_row, JBLOCKROW output_row,
JDIMENSION num_blocks));
EXTERN(void) jzero_far JPP((void FAR * target, size_t bytestozero));
/* Constant tables in jutils.c */
#if 0 /* This table is not actually needed in v6a */
extern const int jpeg_zigzag_order[]; /* natural coef order to zigzag order */
#endif
extern const int jpeg_natural_order[]; /* zigzag coef order to natural order */
/* Suppress undefined-structure complaints if necessary. */
#ifdef INCOMPLETE_TYPES_BROKEN
#ifndef AM_MEMORY_MANAGER /* only jmemmgr.c defines these */
struct jvirt_sarray_control { long dummy; };
struct jvirt_barray_control { long dummy; };
#endif
#endif /* INCOMPLETE_TYPES_BROKEN */
--- NEW FILE: ckconfig.c ---
/*
* ckconfig.c
*
* Copyright (C) 1991-1994, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*/
/*
* This program is intended to help you determine how to configure the JPEG
* software for installation on a particular system. The idea is to try to
* compile and execute this program. If your compiler fails to compile the
* program, make changes as indicated in the comments below. Once you can
* compile the program, run it, and it will produce a "jconfig.h" file for
* your system.
*
* As a general rule, each time you try to compile this program,
* pay attention only to the *first* error message you get from the compiler.
* Many C compilers will issue lots of spurious error messages once they
* have gotten confused. Go to the line indicated in the first error message,
* and read the comments preceding that line to see what to change.
*
* Almost all of the edits you may need to make to this program consist of
* changing a line that reads "#define SOME_SYMBOL" to "#undef SOME_SYMBOL",
* or vice versa. This is called defining or undefining that symbol.
*/
/* First we must see if your system has the include files we need.
* We start out with the assumption that your system has all the ANSI-standard
* include files. If you get any error trying to include one of these files,
* undefine the corresponding HAVE_xxx symbol.
*/
#define HAVE_STDDEF_H /* replace 'define' by 'undef' if error here */
#ifdef HAVE_STDDEF_H /* next line will be skipped if you undef... */
#include <stddef.h>
#endif
#define HAVE_STDLIB_H /* same thing for stdlib.h */
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <stdio.h> /* If you ain't got this, you ain't got C. */
/* We have to see if your string functions are defined by
* strings.h (old BSD convention) or string.h (everybody else).
* We try the non-BSD convention first; define NEED_BSD_STRINGS
* if the compiler says it can't find string.h.
*/
#undef NEED_BSD_STRINGS
#ifdef NEED_BSD_STRINGS
#include <strings.h>
#else
#include <string.h>
#endif
/* On some systems (especially older Unix machines), type size_t is
* defined only in the include file <sys/types.h>. If you get a failure
* on the size_t test below, try defining NEED_SYS_TYPES_H.
*/
#undef NEED_SYS_TYPES_H /* start by assuming we don't need it */
#ifdef NEED_SYS_TYPES_H
#include <sys/types.h>
#endif
/* Usually type size_t is defined in one of the include files we've included
* above. If not, you'll get an error on the "typedef size_t my_size_t;" line.
* In that case, first try defining NEED_SYS_TYPES_H just above.
* If that doesn't work, you'll have to search through your system library
* to figure out which include file defines "size_t". Look for a line that
* says "typedef something-or-other size_t;". Then, change the line below
* that says "#include <someincludefile.h>" to instead include the file
* you found size_t in, and define NEED_SPECIAL_INCLUDE. If you can't find
* type size_t anywhere, try replacing "#include <someincludefile.h>" with
* "typedef unsigned int size_t;".
*/
#undef NEED_SPECIAL_INCLUDE /* assume we DON'T need it, for starters */
#ifdef NEED_SPECIAL_INCLUDE
#include <someincludefile.h>
#endif
typedef size_t my_size_t; /* The payoff: do we have size_t now? */
/* The next question is whether your compiler supports ANSI-style function
* prototypes. You need to know this in order to choose between using
* makefile.ansi and using makefile.unix.
* The #define line below is set to assume you have ANSI function prototypes.
* If you get an error in this group of lines, undefine HAVE_PROTOTYPES.
*/
#define HAVE_PROTOTYPES
#ifdef HAVE_PROTOTYPES
int testfunction (int arg1, int * arg2); /* check prototypes */
struct methods_struct { /* check method-pointer declarations */
int (*error_exit) (char *msgtext);
int (*trace_message) (char *msgtext);
int (*another_method) (void);
};
int testfunction (int arg1, int * arg2) /* check definitions */
{
return arg2[arg1];
}
int test2function (void) /* check void arg list */
{
return 0;
}
#endif
/* Now we want to find out if your compiler knows what "unsigned char" means.
* If you get an error on the "unsigned char un_char;" line,
* then undefine HAVE_UNSIGNED_CHAR.
*/
#define HAVE_UNSIGNED_CHAR
#ifdef HAVE_UNSIGNED_CHAR
unsigned char un_char;
#endif
/* Now we want to find out if your compiler knows what "unsigned short" means.
* If you get an error on the "unsigned short un_short;" line,
* then undefine HAVE_UNSIGNED_SHORT.
*/
#define HAVE_UNSIGNED_SHORT
#ifdef HAVE_UNSIGNED_SHORT
unsigned short un_short;
#endif
/* Now we want to find out if your compiler understands type "void".
* If you get an error anywhere in here, undefine HAVE_VOID.
*/
#define HAVE_VOID
#ifdef HAVE_VOID
/* Caution: a C++ compiler will insist on complete prototypes */
typedef void * void_ptr; /* check void * */
#ifdef HAVE_PROTOTYPES /* check ptr to function returning void */
typedef void (*void_func) (int a, int b);
#else
typedef void (*void_func) ();
#endif
#ifdef HAVE_PROTOTYPES /* check void function result */
void test3function (void_ptr arg1, void_func arg2)
#else
void test3function (arg1, arg2)
void_ptr arg1;
void_func arg2;
#endif
{
char * locptr = (char *) arg1; /* check casting to and from void * */
arg1 = (void *) locptr;
(*arg2) (1, 2); /* check call of fcn returning void */
}
#endif
/* Now we want to find out if your compiler knows what "const" means.
* If you get an error here, undefine HAVE_CONST.
*/
#define HAVE_CONST
#ifdef HAVE_CONST
static const int carray[3] = {1, 2, 3};
#ifdef HAVE_PROTOTYPES
int test4function (const int arg1)
#else
int test4function (arg1)
const int arg1;
#endif
{
return carray[arg1];
}
#endif
/* If you get an error or warning about this structure definition,
* define INCOMPLETE_TYPES_BROKEN.
*/
#undef INCOMPLETE_TYPES_BROKEN
#ifndef INCOMPLETE_TYPES_BROKEN
typedef struct undefined_structure * undef_struct_ptr;
#endif
/* If you get an error about duplicate names,
* define NEED_SHORT_EXTERNAL_NAMES.
*/
#undef NEED_SHORT_EXTERNAL_NAMES
#ifndef NEED_SHORT_EXTERNAL_NAMES
int possibly_duplicate_function ()
{
return 0;
}
int possibly_dupli_function ()
{
return 1;
}
#endif
/************************************************************************
* OK, that's it. You should not have to change anything beyond this
* point in order to compile and execute this program. (You might get
* some warnings, but you can ignore them.)
* When you run the program, it will make a couple more tests that it
* can do automatically, and then it will create jconfig.h and print out
* any additional suggestions it has.
************************************************************************
*/
#ifdef HAVE_PROTOTYPES
int is_char_signed (int arg)
#else
int is_char_signed (arg)
int arg;
#endif
{
if (arg == 189) { /* expected result for unsigned char */
return 0; /* type char is unsigned */
}
else if (arg != -67) { /* expected result for signed char */
printf("Hmm, it seems 'char' is not eight bits wide on your machine.\n");
printf("I fear the JPEG software will not work at all.\n\n");
}
return 1; /* assume char is signed otherwise */
}
#ifdef HAVE_PROTOTYPES
int is_shifting_signed (long arg)
#else
int is_shifting_signed (arg)
long arg;
#endif
/* See whether right-shift on a long is signed or not. */
{
long res = arg >> 4;
if (res == -0x7F7E80CL) { /* expected result for signed shift */
return 1; /* right shift is signed */
}
/* see if unsigned-shift hack will fix it. */
/* we can't just test exact value since it depends on width of long... */
res |= (~0L) << (32-4);
if (res == -0x7F7E80CL) { /* expected result now? */
return 0; /* right shift is unsigned */
}
printf("Right shift isn't acting as I expect it to.\n");
printf("I fear the JPEG software will not work at all.\n\n");
return 0; /* try it with unsigned anyway */
}
#ifdef HAVE_PROTOTYPES
int main (int argc, char ** argv)
#else
int main (argc, argv)
int argc;
char ** argv;
#endif
{
char signed_char_check = (char) (-67);
FILE *outfile;
/* Attempt to write jconfig.h */
if ((outfile = fopen("jconfig.h", "w")) == NULL) {
printf("Failed to write jconfig.h\n");
return 1;
}
/* Write out all the info */
fprintf(outfile, "/* jconfig.h --- generated by ckconfig.c */\n");
fprintf(outfile, "/* see jconfig.doc for explanations */\n\n");
#ifdef HAVE_PROTOTYPES
fprintf(outfile, "#define HAVE_PROTOTYPES\n");
#else
fprintf(outfile, "#undef HAVE_PROTOTYPES\n");
#endif
#ifdef HAVE_UNSIGNED_CHAR
fprintf(outfile, "#define HAVE_UNSIGNED_CHAR\n");
#else
fprintf(outfile, "#undef HAVE_UNSIGNED_CHAR\n");
#endif
#ifdef HAVE_UNSIGNED_SHORT
fprintf(outfile, "#define HAVE_UNSIGNED_SHORT\n");
#else
fprintf(outfile, "#undef HAVE_UNSIGNED_SHORT\n");
#endif
#ifdef HAVE_VOID
fprintf(outfile, "/* #define void char */\n");
#else
fprintf(outfile, "#define void char\n");
#endif
#ifdef HAVE_CONST
fprintf(outfile, "/* #define const */\n");
#else
fprintf(outfile, "#define const\n");
#endif
if (is_char_signed((int) signed_char_check))
fprintf(outfile, "#undef CHAR_IS_UNSIGNED\n");
else
fprintf(outfile, "#define CHAR_IS_UNSIGNED\n");
#ifdef HAVE_STDDEF_H
fprintf(outfile, "#define HAVE_STDDEF_H\n");
#else
fprintf(outfile, "#undef HAVE_STDDEF_H\n");
#endif
#ifdef HAVE_STDLIB_H
fprintf(outfile, "#define HAVE_STDLIB_H\n");
#else
fprintf(outfile, "#undef HAVE_STDLIB_H\n");
#endif
#ifdef NEED_BSD_STRINGS
fprintf(outfile, "#define NEED_BSD_STRINGS\n");
#else
fprintf(outfile, "#undef NEED_BSD_STRINGS\n");
#endif
#ifdef NEED_SYS_TYPES_H
fprintf(outfile, "#define NEED_SYS_TYPES_H\n");
#else
fprintf(outfile, "#undef NEED_SYS_TYPES_H\n");
#endif
fprintf(outfile, "#undef NEED_FAR_POINTERS\n");
#ifdef NEED_SHORT_EXTERNAL_NAMES
fprintf(outfile, "#define NEED_SHORT_EXTERNAL_NAMES\n");
#else
fprintf(outfile, "#undef NEED_SHORT_EXTERNAL_NAMES\n");
#endif
#ifdef INCOMPLETE_TYPES_BROKEN
fprintf(outfile, "#define INCOMPLETE_TYPES_BROKEN\n");
#else
fprintf(outfile, "#undef INCOMPLETE_TYPES_BROKEN\n");
#endif
fprintf(outfile, "\n#ifdef JPEG_INTERNALS\n\n");
if (is_shifting_signed(-0x7F7E80B1L))
fprintf(outfile, "#undef RIGHT_SHIFT_IS_UNSIGNED\n");
else
fprintf(outfile, "#define RIGHT_SHIFT_IS_UNSIGNED\n");
fprintf(outfile, "\n#endif /* JPEG_INTERNALS */\n");
fprintf(outfile, "\n#ifdef JPEG_CJPEG_DJPEG\n\n");
fprintf(outfile, "#define BMP_SUPPORTED /* BMP image file format */\n");
fprintf(outfile, "#define GIF_SUPPORTED /* GIF image file format */\n");
fprintf(outfile, "#define PPM_SUPPORTED /* PBMPLUS PPM/PGM image file format */\n");
fprintf(outfile, "#undef RLE_SUPPORTED /* Utah RLE image file format */\n");
fprintf(outfile, "#define TARGA_SUPPORTED /* Targa image file format */\n\n");
fprintf(outfile, "#undef TWO_FILE_COMMANDLINE /* You may need this on non-Unix systems */\n");
fprintf(outfile, "#undef NEED_SIGNAL_CATCHER /* Define this if you use jmemname.c */\n");
fprintf(outfile, "#undef DONT_USE_B_MODE\n");
fprintf(outfile, "/* #define PROGRESS_REPORT */ /* optional */\n");
fprintf(outfile, "\n#endif /* JPEG_CJPEG_DJPEG */\n");
/* Close the jconfig.h file */
fclose(outfile);
/* User report */
printf("Configuration check for Independent JPEG Group's software done.\n");
printf("\nI have written the jconfig.h file for you.\n\n");
#ifdef HAVE_PROTOTYPES
printf("You should use makefile.ansi as the starting point for your Makefile.\n");
#else
printf("You should use makefile.unix as the starting point for your Makefile.\n");
#endif
#ifdef NEED_SPECIAL_INCLUDE
printf("\nYou'll need to change jconfig.h to include the system include file\n");
printf("that you found type size_t in, or add a direct definition of type\n");
printf("size_t if that's what you used. Just add it to the end.\n");
#endif
return 0;
}
--- NEW FILE: jidctred.c ---
/*
* jidctred.c
*
* Copyright (C) 1994-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains inverse-DCT routines that produce reduced-size output:
* either 4x4, 2x2, or 1x1 pixels from an 8x8 DCT block.
*
* The implementation is based on the Loeffler, Ligtenberg and Moschytz (LL&M)
* algorithm used in jidctint.c. We simply replace each 8-to-8 1-D IDCT step
* with an 8-to-4 step that produces the four averages of two adjacent outputs
* (or an 8-to-2 step producing two averages of four outputs, for 2x2 output).
* These steps were derived by computing the corresponding values at the end
* of the normal LL&M code, then simplifying as much as possible.
*
* 1x1 is trivial: just take the DC coefficient divided by 8.
*
* See jidctint.c for additional comments.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
#ifdef IDCT_SCALING_SUPPORTED
/*
* This module is specialized to the case DCTSIZE = 8.
*/
#if DCTSIZE != 8
Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
#endif
/* Scaling is the same as in jidctint.c. */
#if BITS_IN_JSAMPLE == 8
#define CONST_BITS 13
#define PASS1_BITS 2
#else
#define CONST_BITS 13
#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
#endif
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
* causing a lot of useless floating-point operations at run time.
* To get around this we use the following pre-calculated constants.
* If you change CONST_BITS you may want to add appropriate values.
* (With a reasonable C compiler, you can just rely on the FIX() macro...)
*/
#if CONST_BITS == 13
#define FIX_0_211164243 ((INT32) 1730) /* FIX(0.211164243) */
#define FIX_0_509795579 ((INT32) 4176) /* FIX(0.509795579) */
#define FIX_0_601344887 ((INT32) 4926) /* FIX(0.601344887) */
#define FIX_0_720959822 ((INT32) 5906) /* FIX(0.720959822) */
#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
#define FIX_0_850430095 ((INT32) 6967) /* FIX(0.850430095) */
#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
#define FIX_1_061594337 ((INT32) 8697) /* FIX(1.061594337) */
#define FIX_1_272758580 ((INT32) 10426) /* FIX(1.272758580) */
#define FIX_1_451774981 ((INT32) 11893) /* FIX(1.451774981) */
#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
#define FIX_2_172734803 ((INT32) 17799) /* FIX(2.172734803) */
#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
#define FIX_3_624509785 ((INT32) 29692) /* FIX(3.624509785) */
#else
#define FIX_0_211164243 FIX(0.211164243)
#define FIX_0_509795579 FIX(0.509795579)
#define FIX_0_601344887 FIX(0.601344887)
#define FIX_0_720959822 FIX(0.720959822)
#define FIX_0_765366865 FIX(0.765366865)
#define FIX_0_850430095 FIX(0.850430095)
#define FIX_0_899976223 FIX(0.899976223)
#define FIX_1_061594337 FIX(1.061594337)
#define FIX_1_272758580 FIX(1.272758580)
#define FIX_1_451774981 FIX(1.451774981)
#define FIX_1_847759065 FIX(1.847759065)
#define FIX_2_172734803 FIX(2.172734803)
#define FIX_2_562915447 FIX(2.562915447)
#define FIX_3_624509785 FIX(3.624509785)
#endif
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
* For 8-bit samples with the recommended scaling, all the variable
* and constant values involved are no more than 16 bits wide, so a
* 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
* For 12-bit samples, a full 32-bit multiplication will be needed.
*/
#if BITS_IN_JSAMPLE == 8
#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
#else
#define MULTIPLY(var,const) ((var) * (const))
#endif
/* Dequantize a coefficient by multiplying it by the multiplier-table
* entry; produce an int result. In this module, both inputs and result
* are 16 bits or less, so either int or short multiply will work.
*/
#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
/*
* Perform dequantization and inverse DCT on one block of coefficients,
* producing a reduced-size 4x4 output block.
*/
GLOBAL(void)
jpeg_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
INT32 tmp0, tmp2, tmp10, tmp12;
INT32 z1, z2, z3, z4;
JCOEFPTR inptr;
ISLOW_MULT_TYPE * quantptr;
int * wsptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[DCTSIZE*4]; /* buffers data between passes */
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array. */
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) {
/* Don't bother to process column 4, because second pass won't use it */
if (ctr == DCTSIZE-4)
continue;
if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*5] == 0 &&
inptr[DCTSIZE*6] == 0 && inptr[DCTSIZE*7] == 0) {
/* AC terms all zero; we need not examine term 4 for 4x4 output */
int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
wsptr[DCTSIZE*0] = dcval;
wsptr[DCTSIZE*1] = dcval;
wsptr[DCTSIZE*2] = dcval;
wsptr[DCTSIZE*3] = dcval;
continue;
}
/* Even part */
tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
tmp0 <<= (CONST_BITS+1);
z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
tmp2 = MULTIPLY(z2, FIX_1_847759065) + MULTIPLY(z3, - FIX_0_765366865);
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
/* Odd part */
z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
z2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
z4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */
+ MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */
+ MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */
+ MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */
tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */
+ MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */
+ MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */
+ MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */
/* Final output stage */
wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp2, CONST_BITS-PASS1_BITS+1);
wsptr[DCTSIZE*3] = (int) DESCALE(tmp10 - tmp2, CONST_BITS-PASS1_BITS+1);
wsptr[DCTSIZE*1] = (int) DESCALE(tmp12 + tmp0, CONST_BITS-PASS1_BITS+1);
wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 - tmp0, CONST_BITS-PASS1_BITS+1);
}
/* Pass 2: process 4 rows from work array, store into output array. */
wsptr = workspace;
for (ctr = 0; ctr < 4; ctr++) {
outptr = output_buf[ctr] + output_col;
/* It's not clear whether a zero row test is worthwhile here ... */
#ifndef NO_ZERO_ROW_TEST
if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 &&
wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
/* AC terms all zero */
JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
& RANGE_MASK];
outptr[0] = dcval;
outptr[1] = dcval;
outptr[2] = dcval;
outptr[3] = dcval;
wsptr += DCTSIZE; /* advance pointer to next row */
continue;
}
#endif
/* Even part */
tmp0 = ((INT32) wsptr[0]) << (CONST_BITS+1);
tmp2 = MULTIPLY((INT32) wsptr[2], FIX_1_847759065)
+ MULTIPLY((INT32) wsptr[6], - FIX_0_765366865);
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
/* Odd part */
z1 = (INT32) wsptr[7];
z2 = (INT32) wsptr[5];
z3 = (INT32) wsptr[3];
z4 = (INT32) wsptr[1];
tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */
+ MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */
+ MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */
+ MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */
tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */
+ MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */
+ MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */
+ MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */
/* Final output stage */
outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp2,
CONST_BITS+PASS1_BITS+3+1)
& RANGE_MASK];
outptr[3] = range_limit[(int) DESCALE(tmp10 - tmp2,
CONST_BITS+PASS1_BITS+3+1)
& RANGE_MASK];
outptr[1] = range_limit[(int) DESCALE(tmp12 + tmp0,
CONST_BITS+PASS1_BITS+3+1)
& RANGE_MASK];
outptr[2] = range_limit[(int) DESCALE(tmp12 - tmp0,
CONST_BITS+PASS1_BITS+3+1)
& RANGE_MASK];
wsptr += DCTSIZE; /* advance pointer to next row */
}
}
/*
* Perform dequantization and inverse DCT on one block of coefficients,
* producing a reduced-size 2x2 output block.
*/
GLOBAL(void)
jpeg_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
INT32 tmp0, tmp10, z1;
JCOEFPTR inptr;
ISLOW_MULT_TYPE * quantptr;
int * wsptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[DCTSIZE*2]; /* buffers data between passes */
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array. */
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) {
/* Don't bother to process columns 2,4,6 */
if (ctr == DCTSIZE-2 || ctr == DCTSIZE-4 || ctr == DCTSIZE-6)
continue;
if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*3] == 0 &&
inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*7] == 0) {
/* AC terms all zero; we need not examine terms 2,4,6 for 2x2 output */
int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
wsptr[DCTSIZE*0] = dcval;
wsptr[DCTSIZE*1] = dcval;
continue;
}
/* Even part */
z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
tmp10 = z1 << (CONST_BITS+2);
/* Odd part */
z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
tmp0 = MULTIPLY(z1, - FIX_0_720959822); /* sqrt(2) * (c7-c5+c3-c1) */
z1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
tmp0 += MULTIPLY(z1, FIX_0_850430095); /* sqrt(2) * (-c1+c3+c5+c7) */
z1 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
tmp0 += MULTIPLY(z1, - FIX_1_272758580); /* sqrt(2) * (-c1+c3-c5-c7) */
z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
tmp0 += MULTIPLY(z1, FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */
/* Final output stage */
wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp0, CONST_BITS-PASS1_BITS+2);
wsptr[DCTSIZE*1] = (int) DESCALE(tmp10 - tmp0, CONST_BITS-PASS1_BITS+2);
}
/* Pass 2: process 2 rows from work array, store into output array. */
wsptr = workspace;
for (ctr = 0; ctr < 2; ctr++) {
outptr = output_buf[ctr] + output_col;
/* It's not clear whether a zero row test is worthwhile here ... */
#ifndef NO_ZERO_ROW_TEST
if (wsptr[1] == 0 && wsptr[3] == 0 && wsptr[5] == 0 && wsptr[7] == 0) {
/* AC terms all zero */
JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
& RANGE_MASK];
outptr[0] = dcval;
outptr[1] = dcval;
wsptr += DCTSIZE; /* advance pointer to next row */
continue;
}
#endif
/* Even part */
tmp10 = ((INT32) wsptr[0]) << (CONST_BITS+2);
/* Odd part */
tmp0 = MULTIPLY((INT32) wsptr[7], - FIX_0_720959822) /* sqrt(2) * (c7-c5+c3-c1) */
+ MULTIPLY((INT32) wsptr[5], FIX_0_850430095) /* sqrt(2) * (-c1+c3+c5+c7) */
+ MULTIPLY((INT32) wsptr[3], - FIX_1_272758580) /* sqrt(2) * (-c1+c3-c5-c7) */
+ MULTIPLY((INT32) wsptr[1], FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */
/* Final output stage */
outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp0,
CONST_BITS+PASS1_BITS+3+2)
& RANGE_MASK];
outptr[1] = range_limit[(int) DESCALE(tmp10 - tmp0,
CONST_BITS+PASS1_BITS+3+2)
& RANGE_MASK];
wsptr += DCTSIZE; /* advance pointer to next row */
}
}
/*
* Perform dequantization and inverse DCT on one block of coefficients,
* producing a reduced-size 1x1 output block.
*/
GLOBAL(void)
jpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
int dcval;
ISLOW_MULT_TYPE * quantptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
SHIFT_TEMPS
/* We hardly need an inverse DCT routine for this: just take the
* average pixel value, which is one-eighth of the DC coefficient.
*/
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
dcval = DEQUANTIZE(coef_block[0], quantptr[0]);
dcval = (int) DESCALE((INT32) dcval, 3);
output_buf[0][output_col] = range_limit[dcval & RANGE_MASK];
}
#endif /* IDCT_SCALING_SUPPORTED */
--- NEW FILE: jpeglib.h ---
/*
* jpeglib.h
*
* Copyright (C) 1991-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file defines the application interface for the JPEG library.
* Most applications using the library need only include this file,
* and perhaps jerror.h if they want to know the exact error codes.
*/
#ifndef JPEGLIB_H
#define JPEGLIB_H
/*
* First we include the configuration files that record how this
* installation of the JPEG library is set up. jconfig.h can be
* generated automatically for many systems. jmorecfg.h contains
[...1057 lines suppressed...]
struct jpeg_upsampler { long dummy; };
struct jpeg_color_deconverter { long dummy; };
struct jpeg_color_quantizer { long dummy; };
#endif /* JPEG_INTERNALS */
#endif /* INCOMPLETE_TYPES_BROKEN */
/*
* The JPEG library modules define JPEG_INTERNALS before including this file.
* The internal structure declarations are read only when that is true.
* Applications using the library should not include jpegint.h, but may wish
* to include jerror.h.
*/
#ifdef JPEG_INTERNALS
#include "jpegint.h" /* fetch private declarations */
#include "jerror.h" /* fetch error codes too */
#endif
#endif /* JPEGLIB_H */
--- NEW FILE: jdhuff.h ---
/*
* jdhuff.h
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains declarations for Huffman entropy decoding routines
* that are shared between the sequential decoder (jdhuff.c) and the
* progressive decoder (jdphuff.c). No other modules need to see these.
*/
/* Short forms of external names for systems with brain-damaged linkers. */
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_make_d_derived_tbl jMkDDerived
#define jpeg_fill_bit_buffer jFilBitBuf
#define jpeg_huff_decode jHufDecode
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/* Derived data constructed for each Huffman table */
#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */
typedef struct {
/* Basic tables: (element [0] of each array is unused) */
INT32 maxcode[18]; /* largest code of length k (-1 if none) */
/* (maxcode[17] is a sentinel to ensure jpeg_huff_decode terminates) */
INT32 valoffset[17]; /* huffval[] offset for codes of length k */
/* valoffset[k] = huffval[] index of 1st symbol of code length k, less
* the smallest code of length k; so given a code of length k, the
* corresponding symbol is huffval[code + valoffset[k]]
*/
/* Link to public Huffman table (needed only in jpeg_huff_decode) */
JHUFF_TBL *pub;
/* Lookahead tables: indexed by the next HUFF_LOOKAHEAD bits of
* the input data stream. If the next Huffman code is no more
* than HUFF_LOOKAHEAD bits long, we can obtain its length and
* the corresponding symbol directly from these tables.
*/
int look_nbits[1<<HUFF_LOOKAHEAD]; /* # bits, or 0 if too long */
UINT8 look_sym[1<<HUFF_LOOKAHEAD]; /* symbol, or unused */
} d_derived_tbl;
/* Expand a Huffman table definition into the derived format */
EXTERN(void) jpeg_make_d_derived_tbl
JPP((j_decompress_ptr cinfo, boolean isDC, int tblno,
d_derived_tbl ** pdtbl));
/*
* Fetching the next N bits from the input stream is a time-critical operation
* for the Huffman decoders. We implement it with a combination of inline
* macros and out-of-line subroutines. Note that N (the number of bits
* demanded at one time) never exceeds 15 for JPEG use.
*
* We read source bytes into get_buffer and dole out bits as needed.
* If get_buffer already contains enough bits, they are fetched in-line
* by the macros CHECK_BIT_BUFFER and GET_BITS. When there aren't enough
* bits, jpeg_fill_bit_buffer is called; it will attempt to fill get_buffer
* as full as possible (not just to the number of bits needed; this
* prefetching reduces the overhead cost of calling jpeg_fill_bit_buffer).
* Note that jpeg_fill_bit_buffer may return FALSE to indicate suspension.
* On TRUE return, jpeg_fill_bit_buffer guarantees that get_buffer contains
* at least the requested number of bits --- dummy zeroes are inserted if
* necessary.
*/
typedef INT32 bit_buf_type; /* type of bit-extraction buffer */
#define BIT_BUF_SIZE 32 /* size of buffer in bits */
/* If long is > 32 bits on your machine, and shifting/masking longs is
* reasonably fast, making bit_buf_type be long and setting BIT_BUF_SIZE
* appropriately should be a win. Unfortunately we can't define the size
* with something like #define BIT_BUF_SIZE (sizeof(bit_buf_type)*8)
* because not all machines measure sizeof in 8-bit bytes.
*/
typedef struct { /* Bitreading state saved across MCUs */
bit_buf_type get_buffer; /* current bit-extraction buffer */
int bits_left; /* # of unused bits in it */
} bitread_perm_state;
typedef struct { /* Bitreading working state within an MCU */
/* Current data source location */
/* We need a copy, rather than munging the original, in case of suspension */
const JOCTET * next_input_byte; /* => next byte to read from source */
size_t bytes_in_buffer; /* # of bytes remaining in source buffer */
/* Bit input buffer --- note these values are kept in register variables,
* not in this struct, inside the inner loops.
*/
bit_buf_type get_buffer; /* current bit-extraction buffer */
int bits_left; /* # of unused bits in it */
/* Pointer needed by jpeg_fill_bit_buffer. */
j_decompress_ptr cinfo; /* back link to decompress master record */
} bitread_working_state;
/* Macros to declare and load/save bitread local variables. */
#define BITREAD_STATE_VARS \
register bit_buf_type get_buffer; \
register int bits_left; \
bitread_working_state br_state
#define BITREAD_LOAD_STATE(cinfop,permstate) \
br_state.cinfo = cinfop; \
br_state.next_input_byte = cinfop->src->next_input_byte; \
br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \
get_buffer = permstate.get_buffer; \
bits_left = permstate.bits_left;
#define BITREAD_SAVE_STATE(cinfop,permstate) \
cinfop->src->next_input_byte = br_state.next_input_byte; \
cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \
permstate.get_buffer = get_buffer; \
permstate.bits_left = bits_left
/*
* These macros provide the in-line portion of bit fetching.
* Use CHECK_BIT_BUFFER to ensure there are N bits in get_buffer
* before using GET_BITS, PEEK_BITS, or DROP_BITS.
* The variables get_buffer and bits_left are assumed to be locals,
* but the state struct might not be (jpeg_huff_decode needs this).
* CHECK_BIT_BUFFER(state,n,action);
* Ensure there are N bits in get_buffer; if suspend, take action.
* val = GET_BITS(n);
* Fetch next N bits.
* val = PEEK_BITS(n);
* Fetch next N bits without removing them from the buffer.
* DROP_BITS(n);
* Discard next N bits.
* The value N should be a simple variable, not an expression, because it
* is evaluated multiple times.
*/
#define CHECK_BIT_BUFFER(state,nbits,action) \
{ if (bits_left < (nbits)) { \
if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits)) \
{ action; } \
get_buffer = (state).get_buffer; bits_left = (state).bits_left; } }
#define GET_BITS(nbits) \
(((int) (get_buffer >> (bits_left -= (nbits)))) & ((1<<(nbits))-1))
#define PEEK_BITS(nbits) \
(((int) (get_buffer >> (bits_left - (nbits)))) & ((1<<(nbits))-1))
#define DROP_BITS(nbits) \
(bits_left -= (nbits))
/* Load up the bit buffer to a depth of at least nbits */
EXTERN(boolean) jpeg_fill_bit_buffer
JPP((bitread_working_state * state, register bit_buf_type get_buffer,
register int bits_left, int nbits));
/*
* Code for extracting next Huffman-coded symbol from input bit stream.
* Again, this is time-critical and we make the main paths be macros.
*
* We use a lookahead table to process codes of up to HUFF_LOOKAHEAD bits
* without looping. Usually, more than 95% of the Huffman codes will be 8
* or fewer bits long. The few overlength codes are handled with a loop,
* which need not be inline code.
*
* Notes about the HUFF_DECODE macro:
* 1. Near the end of the data segment, we may fail to get enough bits
* for a lookahead. In that case, we do it the hard way.
* 2. If the lookahead table contains no entry, the next code must be
* more than HUFF_LOOKAHEAD bits long.
* 3. jpeg_huff_decode returns -1 if forced to suspend.
*/
#define HUFF_DECODE(result,state,htbl,failaction,slowlabel) \
{ register int nb, look; \
if (bits_left < HUFF_LOOKAHEAD) { \
if (! jpeg_fill_bit_buffer(&state,get_buffer,bits_left, 0)) {failaction;} \
get_buffer = state.get_buffer; bits_left = state.bits_left; \
if (bits_left < HUFF_LOOKAHEAD) { \
nb = 1; goto slowlabel; \
} \
} \
look = PEEK_BITS(HUFF_LOOKAHEAD); \
if ((nb = htbl->look_nbits[look]) != 0) { \
DROP_BITS(nb); \
result = htbl->look_sym[look]; \
} else { \
nb = HUFF_LOOKAHEAD+1; \
slowlabel: \
if ((result=jpeg_huff_decode(&state,get_buffer,bits_left,htbl,nb)) < 0) \
{ failaction; } \
get_buffer = state.get_buffer; bits_left = state.bits_left; \
} \
}
/* Out-of-line case for Huffman code fetching */
EXTERN(int) jpeg_huff_decode
JPP((bitread_working_state * state, register bit_buf_type get_buffer,
register int bits_left, d_derived_tbl * htbl, int min_bits));
--- NEW FILE: jdcoefct.c ---
/*
* jdcoefct.c
*
* Copyright (C) 1994-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains the coefficient buffer controller for decompression.
* This controller is the top level of the JPEG decompressor proper.
* The coefficient buffer lies between entropy decoding and inverse-DCT steps.
*
* In buffered-image mode, this controller is the interface between
* input-oriented processing and output-oriented processing.
* Also, the input side (only) is used when reading a file for transcoding.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Block smoothing is only applicable for progressive JPEG, so: */
#ifndef D_PROGRESSIVE_SUPPORTED
#undef BLOCK_SMOOTHING_SUPPORTED
#endif
/* Private buffer controller object */
typedef struct {
struct jpeg_d_coef_controller pub; /* public fields */
/* These variables keep track of the current location of the input side. */
/* cinfo->input_iMCU_row is also used for this. */
JDIMENSION MCU_ctr; /* counts MCUs processed in current row */
int MCU_vert_offset; /* counts MCU rows within iMCU row */
int MCU_rows_per_iMCU_row; /* number of such rows needed */
/* The output side's location is represented by cinfo->output_iMCU_row. */
/* In single-pass modes, it's sufficient to buffer just one MCU.
* We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
* and let the entropy decoder write into that workspace each time.
* (On 80x86, the workspace is FAR even though it's not really very big;
* this is to keep the module interfaces unchanged when a large coefficient
* buffer is necessary.)
* In multi-pass modes, this array points to the current MCU's blocks
* within the virtual arrays; it is used only by the input side.
*/
JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
#ifdef D_MULTISCAN_FILES_SUPPORTED
/* In multi-pass modes, we need a virtual block array for each component. */
jvirt_barray_ptr whole_image[MAX_COMPONENTS];
#endif
#ifdef BLOCK_SMOOTHING_SUPPORTED
/* When doing block smoothing, we latch coefficient Al values here */
int * coef_bits_latch;
#define SAVED_COEFS 6 /* we save coef_bits[0..5] */
#endif
} my_coef_controller;
typedef my_coef_controller * my_coef_ptr;
/* Forward declarations */
METHODDEF(int) decompress_onepass
JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
#ifdef D_MULTISCAN_FILES_SUPPORTED
METHODDEF(int) decompress_data
JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
#endif
#ifdef BLOCK_SMOOTHING_SUPPORTED
LOCAL(boolean) smoothing_ok JPP((j_decompress_ptr cinfo));
METHODDEF(int) decompress_smooth_data
JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
#endif
LOCAL(void)
start_iMCU_row (j_decompress_ptr cinfo)
/* Reset within-iMCU-row counters for a new row (input side) */
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
/* In an interleaved scan, an MCU row is the same as an iMCU row.
* In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
* But at the bottom of the image, process only what's left.
*/
if (cinfo->comps_in_scan > 1) {
coef->MCU_rows_per_iMCU_row = 1;
} else {
if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1))
coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
else
coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
}
coef->MCU_ctr = 0;
coef->MCU_vert_offset = 0;
}
/*
* Initialize for an input processing pass.
*/
METHODDEF(void)
start_input_pass (j_decompress_ptr cinfo)
{
cinfo->input_iMCU_row = 0;
start_iMCU_row(cinfo);
}
/*
* Initialize for an output processing pass.
*/
METHODDEF(void)
start_output_pass (j_decompress_ptr cinfo)
{
#ifdef BLOCK_SMOOTHING_SUPPORTED
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
/* If multipass, check to see whether to use block smoothing on this pass */
if (coef->pub.coef_arrays != NULL) {
if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
coef->pub.decompress_data = decompress_smooth_data;
else
coef->pub.decompress_data = decompress_data;
}
#endif
cinfo->output_iMCU_row = 0;
}
/*
* Decompress and return some data in the single-pass case.
* Always attempts to emit one fully interleaved MCU row ("iMCU" row).
* Input and output must run in lockstep since we have only a one-MCU buffer.
* Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
*
* NB: output_buf contains a plane for each component in image,
* which we index according to the component's SOF position.
*/
METHODDEF(int)
decompress_onepass (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
JDIMENSION MCU_col_num; /* index of current MCU within row */
JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
int blkn, ci, xindex, yindex, yoffset, useful_width;
JSAMPARRAY output_ptr;
JDIMENSION start_col, output_col;
jpeg_component_info *compptr;
inverse_DCT_method_ptr inverse_DCT;
/* Loop to process as much as one whole iMCU row */
for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
yoffset++) {
for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
MCU_col_num++) {
/* Try to fetch an MCU. Entropy decoder expects buffer to be zeroed. */
jzero_far((void FAR *) coef->MCU_buffer[0],
(size_t) (cinfo->blocks_in_MCU * SIZEOF(JBLOCK)));
if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
/* Suspension forced; update state counters and exit */
coef->MCU_vert_offset = yoffset;
coef->MCU_ctr = MCU_col_num;
return JPEG_SUSPENDED;
}
/* Determine where data should go in output_buf and do the IDCT thing.
* We skip dummy blocks at the right and bottom edges (but blkn gets
* incremented past them!). Note the inner loop relies on having
* allocated the MCU_buffer[] blocks sequentially.
*/
blkn = 0; /* index of current DCT block within MCU */
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
/* Don't bother to IDCT an uninteresting component. */
if (! compptr->component_needed) {
blkn += compptr->MCU_blocks;
continue;
}
inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
useful_width = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
: compptr->last_col_width;
output_ptr = output_buf[compptr->component_index] +
yoffset * compptr->DCT_scaled_size;
start_col = MCU_col_num * compptr->MCU_sample_width;
for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
if (cinfo->input_iMCU_row < last_iMCU_row ||
yoffset+yindex < compptr->last_row_height) {
output_col = start_col;
for (xindex = 0; xindex < useful_width; xindex++) {
(*inverse_DCT) (cinfo, compptr,
(JCOEFPTR) coef->MCU_buffer[blkn+xindex],
output_ptr, output_col);
output_col += compptr->DCT_scaled_size;
}
}
blkn += compptr->MCU_width;
output_ptr += compptr->DCT_scaled_size;
}
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
coef->MCU_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
cinfo->output_iMCU_row++;
if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
start_iMCU_row(cinfo);
return JPEG_ROW_COMPLETED;
}
/* Completed the scan */
(*cinfo->inputctl->finish_input_pass) (cinfo);
return JPEG_SCAN_COMPLETED;
}
/*
* Dummy consume-input routine for single-pass operation.
*/
METHODDEF(int)
dummy_consume_data (j_decompress_ptr cinfo)
{
return JPEG_SUSPENDED; /* Always indicate nothing was done */
}
#ifdef D_MULTISCAN_FILES_SUPPORTED
/*
* Consume input data and store it in the full-image coefficient buffer.
* We read as much as one fully interleaved MCU row ("iMCU" row) per call,
* ie, v_samp_factor block rows for each component in the scan.
* Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
*/
METHODDEF(int)
consume_data (j_decompress_ptr cinfo)
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
JDIMENSION MCU_col_num; /* index of current MCU within row */
int blkn, ci, xindex, yindex, yoffset;
JDIMENSION start_col;
JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
JBLOCKROW buffer_ptr;
jpeg_component_info *compptr;
/* Align the virtual buffers for the components used in this scan. */
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
buffer[ci] = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
cinfo->input_iMCU_row * compptr->v_samp_factor,
(JDIMENSION) compptr->v_samp_factor, TRUE);
/* Note: entropy decoder expects buffer to be zeroed,
* but this is handled automatically by the memory manager
* because we requested a pre-zeroed array.
*/
}
/* Loop to process one whole iMCU row */
for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
yoffset++) {
for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
MCU_col_num++) {
/* Construct list of pointers to DCT blocks belonging to this MCU */
blkn = 0; /* index of current DCT block within MCU */
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
start_col = MCU_col_num * compptr->MCU_width;
for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
coef->MCU_buffer[blkn++] = buffer_ptr++;
}
}
}
/* Try to fetch the MCU. */
if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
/* Suspension forced; update state counters and exit */
coef->MCU_vert_offset = yoffset;
coef->MCU_ctr = MCU_col_num;
return JPEG_SUSPENDED;
}
}
/* Completed an MCU row, but perhaps not an iMCU row */
coef->MCU_ctr = 0;
}
/* Completed the iMCU row, advance counters for next one */
if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
start_iMCU_row(cinfo);
return JPEG_ROW_COMPLETED;
}
/* Completed the scan */
(*cinfo->inputctl->finish_input_pass) (cinfo);
return JPEG_SCAN_COMPLETED;
}
/*
* Decompress and return some data in the multi-pass case.
* Always attempts to emit one fully interleaved MCU row ("iMCU" row).
* Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
*
* NB: output_buf contains a plane for each component in image.
*/
METHODDEF(int)
decompress_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
JDIMENSION block_num;
int ci, block_row, block_rows;
JBLOCKARRAY buffer;
JBLOCKROW buffer_ptr;
JSAMPARRAY output_ptr;
JDIMENSION output_col;
jpeg_component_info *compptr;
inverse_DCT_method_ptr inverse_DCT;
/* Force some input to be done if we are getting ahead of the input. */
while (cinfo->input_scan_number < cinfo->output_scan_number ||
(cinfo->input_scan_number == cinfo->output_scan_number &&
cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
return JPEG_SUSPENDED;
}
/* OK, output from the virtual arrays. */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Don't bother to IDCT an uninteresting component. */
if (! compptr->component_needed)
continue;
/* Align the virtual buffer for this component. */
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image[ci],
cinfo->output_iMCU_row * compptr->v_samp_factor,
(JDIMENSION) compptr->v_samp_factor, FALSE);
/* Count non-dummy DCT block rows in this iMCU row. */
if (cinfo->output_iMCU_row < last_iMCU_row)
block_rows = compptr->v_samp_factor;
else {
/* NB: can't use last_row_height here; it is input-side-dependent! */
block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
if (block_rows == 0) block_rows = compptr->v_samp_factor;
}
inverse_DCT = cinfo->idct->inverse_DCT[ci];
output_ptr = output_buf[ci];
/* Loop over all DCT blocks to be processed. */
for (block_row = 0; block_row < block_rows; block_row++) {
buffer_ptr = buffer[block_row];
output_col = 0;
for (block_num = 0; block_num < compptr->width_in_blocks; block_num++) {
(*inverse_DCT) (cinfo, compptr, (JCOEFPTR) buffer_ptr,
output_ptr, output_col);
buffer_ptr++;
output_col += compptr->DCT_scaled_size;
}
output_ptr += compptr->DCT_scaled_size;
}
}
if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
return JPEG_ROW_COMPLETED;
return JPEG_SCAN_COMPLETED;
}
#endif /* D_MULTISCAN_FILES_SUPPORTED */
#ifdef BLOCK_SMOOTHING_SUPPORTED
/*
* This code applies interblock smoothing as described by section K.8
* of the JPEG standard: the first 5 AC coefficients are estimated from
* the DC values of a DCT block and its 8 neighboring blocks.
* We apply smoothing only for progressive JPEG decoding, and only if
* the coefficients it can estimate are not yet known to full precision.
*/
/* Natural-order array positions of the first 5 zigzag-order coefficients */
#define Q01_POS 1
#define Q10_POS 8
#define Q20_POS 16
#define Q11_POS 9
#define Q02_POS 2
/*
* Determine whether block smoothing is applicable and safe.
* We also latch the current states of the coef_bits[] entries for the
* AC coefficients; otherwise, if the input side of the decompressor
* advances into a new scan, we might think the coefficients are known
* more accurately than they really are.
*/
LOCAL(boolean)
smoothing_ok (j_decompress_ptr cinfo)
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
boolean smoothing_useful = FALSE;
int ci, coefi;
jpeg_component_info *compptr;
JQUANT_TBL * qtable;
int * coef_bits;
int * coef_bits_latch;
if (! cinfo->progressive_mode || cinfo->coef_bits == NULL)
return FALSE;
/* Allocate latch area if not already done */
if (coef->coef_bits_latch == NULL)
coef->coef_bits_latch = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->num_components *
(SAVED_COEFS * SIZEOF(int)));
coef_bits_latch = coef->coef_bits_latch;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* All components' quantization values must already be latched. */
if ((qtable = compptr->quant_table) == NULL)
return FALSE;
/* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */
if (qtable->quantval[0] == 0 ||
qtable->quantval[Q01_POS] == 0 ||
qtable->quantval[Q10_POS] == 0 ||
qtable->quantval[Q20_POS] == 0 ||
qtable->quantval[Q11_POS] == 0 ||
qtable->quantval[Q02_POS] == 0)
return FALSE;
/* DC values must be at least partly known for all components. */
coef_bits = cinfo->coef_bits[ci];
if (coef_bits[0] < 0)
return FALSE;
/* Block smoothing is helpful if some AC coefficients remain inaccurate. */
for (coefi = 1; coefi <= 5; coefi++) {
coef_bits_latch[coefi] = coef_bits[coefi];
if (coef_bits[coefi] != 0)
smoothing_useful = TRUE;
}
coef_bits_latch += SAVED_COEFS;
}
return smoothing_useful;
}
/*
* Variant of decompress_data for use when doing block smoothing.
*/
METHODDEF(int)
decompress_smooth_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
{
my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
JDIMENSION block_num, last_block_column;
int ci, block_row, block_rows, access_rows;
JBLOCKARRAY buffer;
JBLOCKROW buffer_ptr, prev_block_row, next_block_row;
JSAMPARRAY output_ptr;
JDIMENSION output_col;
jpeg_component_info *compptr;
inverse_DCT_method_ptr inverse_DCT;
boolean first_row, last_row;
JBLOCK workspace;
int *coef_bits;
JQUANT_TBL *quanttbl;
INT32 Q00,Q01,Q02,Q10,Q11,Q20, num;
int DC1,DC2,DC3,DC4,DC5,DC6,DC7,DC8,DC9;
int Al, pred;
/* Force some input to be done if we are getting ahead of the input. */
while (cinfo->input_scan_number <= cinfo->output_scan_number &&
! cinfo->inputctl->eoi_reached) {
if (cinfo->input_scan_number == cinfo->output_scan_number) {
/* If input is working on current scan, we ordinarily want it to
* have completed the current row. But if input scan is DC,
* we want it to keep one row ahead so that next block row's DC
* values are up to date.
*/
JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0;
if (cinfo->input_iMCU_row > cinfo->output_iMCU_row+delta)
break;
}
if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
return JPEG_SUSPENDED;
}
/* OK, output from the virtual arrays. */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Don't bother to IDCT an uninteresting component. */
if (! compptr->component_needed)
continue;
/* Count non-dummy DCT block rows in this iMCU row. */
if (cinfo->output_iMCU_row < last_iMCU_row) {
block_rows = compptr->v_samp_factor;
access_rows = block_rows * 2; /* this and next iMCU row */
last_row = FALSE;
} else {
/* NB: can't use last_row_height here; it is input-side-dependent! */
block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
if (block_rows == 0) block_rows = compptr->v_samp_factor;
access_rows = block_rows; /* this iMCU row only */
last_row = TRUE;
}
/* Align the virtual buffer for this component. */
if (cinfo->output_iMCU_row > 0) {
access_rows += compptr->v_samp_factor; /* prior iMCU row too */
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image[ci],
(cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
(JDIMENSION) access_rows, FALSE);
buffer += compptr->v_samp_factor; /* point to current iMCU row */
first_row = FALSE;
} else {
buffer = (*cinfo->mem->access_virt_barray)
((j_common_ptr) cinfo, coef->whole_image[ci],
(JDIMENSION) 0, (JDIMENSION) access_rows, FALSE);
first_row = TRUE;
}
/* Fetch component-dependent info */
coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
quanttbl = compptr->quant_table;
Q00 = quanttbl->quantval[0];
Q01 = quanttbl->quantval[Q01_POS];
Q10 = quanttbl->quantval[Q10_POS];
Q20 = quanttbl->quantval[Q20_POS];
Q11 = quanttbl->quantval[Q11_POS];
Q02 = quanttbl->quantval[Q02_POS];
inverse_DCT = cinfo->idct->inverse_DCT[ci];
output_ptr = output_buf[ci];
/* Loop over all DCT blocks to be processed. */
for (block_row = 0; block_row < block_rows; block_row++) {
buffer_ptr = buffer[block_row];
if (first_row && block_row == 0)
prev_block_row = buffer_ptr;
else
prev_block_row = buffer[block_row-1];
if (last_row && block_row == block_rows-1)
next_block_row = buffer_ptr;
else
next_block_row = buffer[block_row+1];
/* We fetch the surrounding DC values using a sliding-register approach.
* Initialize all nine here so as to do the right thing on narrow pics.
*/
DC1 = DC2 = DC3 = (int) prev_block_row[0][0];
DC4 = DC5 = DC6 = (int) buffer_ptr[0][0];
DC7 = DC8 = DC9 = (int) next_block_row[0][0];
output_col = 0;
last_block_column = compptr->width_in_blocks - 1;
for (block_num = 0; block_num <= last_block_column; block_num++) {
/* Fetch current DCT block into workspace so we can modify it. */
jcopy_block_row(buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1);
/* Update DC values */
if (block_num < last_block_column) {
DC3 = (int) prev_block_row[1][0];
DC6 = (int) buffer_ptr[1][0];
DC9 = (int) next_block_row[1][0];
}
/* Compute coefficient estimates per K.8.
* An estimate is applied only if coefficient is still zero,
* and is not known to be fully accurate.
*/
/* AC01 */
if ((Al=coef_bits[1]) != 0 && workspace[1] == 0) {
num = 36 * Q00 * (DC4 - DC6);
if (num >= 0) {
pred = (int) (((Q01<<7) + num) / (Q01<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
} else {
pred = (int) (((Q01<<7) - num) / (Q01<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
pred = -pred;
}
workspace[1] = (JCOEF) pred;
}
/* AC10 */
if ((Al=coef_bits[2]) != 0 && workspace[8] == 0) {
num = 36 * Q00 * (DC2 - DC8);
if (num >= 0) {
pred = (int) (((Q10<<7) + num) / (Q10<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
} else {
pred = (int) (((Q10<<7) - num) / (Q10<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
pred = -pred;
}
workspace[8] = (JCOEF) pred;
}
/* AC20 */
if ((Al=coef_bits[3]) != 0 && workspace[16] == 0) {
num = 9 * Q00 * (DC2 + DC8 - 2*DC5);
if (num >= 0) {
pred = (int) (((Q20<<7) + num) / (Q20<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
} else {
pred = (int) (((Q20<<7) - num) / (Q20<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
pred = -pred;
}
workspace[16] = (JCOEF) pred;
}
/* AC11 */
if ((Al=coef_bits[4]) != 0 && workspace[9] == 0) {
num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
if (num >= 0) {
pred = (int) (((Q11<<7) + num) / (Q11<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
} else {
pred = (int) (((Q11<<7) - num) / (Q11<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
pred = -pred;
}
workspace[9] = (JCOEF) pred;
}
/* AC02 */
if ((Al=coef_bits[5]) != 0 && workspace[2] == 0) {
num = 9 * Q00 * (DC4 + DC6 - 2*DC5);
if (num >= 0) {
pred = (int) (((Q02<<7) + num) / (Q02<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
} else {
pred = (int) (((Q02<<7) - num) / (Q02<<8));
if (Al > 0 && pred >= (1<<Al))
pred = (1<<Al)-1;
pred = -pred;
}
workspace[2] = (JCOEF) pred;
}
/* OK, do the IDCT */
(*inverse_DCT) (cinfo, compptr, (JCOEFPTR) workspace,
output_ptr, output_col);
/* Advance for next column */
DC1 = DC2; DC2 = DC3;
DC4 = DC5; DC5 = DC6;
DC7 = DC8; DC8 = DC9;
buffer_ptr++, prev_block_row++, next_block_row++;
output_col += compptr->DCT_scaled_size;
}
output_ptr += compptr->DCT_scaled_size;
}
}
if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
return JPEG_ROW_COMPLETED;
return JPEG_SCAN_COMPLETED;
}
#endif /* BLOCK_SMOOTHING_SUPPORTED */
/*
* Initialize coefficient buffer controller.
*/
GLOBAL(void)
jinit_d_coef_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
{
my_coef_ptr coef;
coef = (my_coef_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_coef_controller));
cinfo->coef = (struct jpeg_d_coef_controller *) coef;
coef->pub.start_input_pass = start_input_pass;
coef->pub.start_output_pass = start_output_pass;
#ifdef BLOCK_SMOOTHING_SUPPORTED
coef->coef_bits_latch = NULL;
#endif
/* Create the coefficient buffer. */
if (need_full_buffer) {
#ifdef D_MULTISCAN_FILES_SUPPORTED
/* Allocate a full-image virtual array for each component, */
/* padded to a multiple of samp_factor DCT blocks in each direction. */
/* Note we ask for a pre-zeroed array. */
int ci, access_rows;
jpeg_component_info *compptr;
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
access_rows = compptr->v_samp_factor;
#ifdef BLOCK_SMOOTHING_SUPPORTED
/* If block smoothing could be used, need a bigger window */
if (cinfo->progressive_mode)
access_rows *= 3;
#endif
coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
((j_common_ptr) cinfo, JPOOL_IMAGE, TRUE,
(JDIMENSION) jround_up((long) compptr->width_in_blocks,
(long) compptr->h_samp_factor),
(JDIMENSION) jround_up((long) compptr->height_in_blocks,
(long) compptr->v_samp_factor),
(JDIMENSION) access_rows);
}
coef->pub.consume_data = consume_data;
coef->pub.decompress_data = decompress_data;
coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
} else {
/* We only need a single-MCU buffer. */
JBLOCKROW buffer;
int i;
buffer = (JBLOCKROW)
(*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
D_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {
coef->MCU_buffer[i] = buffer + i;
}
coef->pub.consume_data = dummy_consume_data;
coef->pub.decompress_data = decompress_onepass;
coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */
}
}
--- NEW FILE: jdmerge.c ---
/*
* jdmerge.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains code for merged upsampling/color conversion.
*
* This file combines functions from jdsample.c and jdcolor.c;
* read those files first to understand what's going on.
*
* When the chroma components are to be upsampled by simple replication
* (ie, box filtering), we can save some work in color conversion by
* calculating all the output pixels corresponding to a pair of chroma
* samples at one time. In the conversion equations
* R = Y + K1 * Cr
* G = Y + K2 * Cb + K3 * Cr
* B = Y + K4 * Cb
* only the Y term varies among the group of pixels corresponding to a pair
* of chroma samples, so the rest of the terms can be calculated just once.
* At typical sampling ratios, this eliminates half or three-quarters of the
* multiplications needed for color conversion.
*
* This file currently provides implementations for the following cases:
* YCbCr => RGB color conversion only.
* Sampling ratios of 2h1v or 2h2v.
* No scaling needed at upsample time.
* Corner-aligned (non-CCIR601) sampling alignment.
* Other special cases could be added, but in most applications these are
* the only common cases. (For uncommon cases we fall back on the more
* general code in jdsample.c and jdcolor.c.)
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#ifdef UPSAMPLE_MERGING_SUPPORTED
/* Private subobject */
typedef struct {
struct jpeg_upsampler pub; /* public fields */
/* Pointer to routine to do actual upsampling/conversion of one row group */
JMETHOD(void, upmethod, (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
JSAMPARRAY output_buf));
/* Private state for YCC->RGB conversion */
int * Cr_r_tab; /* => table for Cr to R conversion */
int * Cb_b_tab; /* => table for Cb to B conversion */
INT32 * Cr_g_tab; /* => table for Cr to G conversion */
INT32 * Cb_g_tab; /* => table for Cb to G conversion */
/* For 2:1 vertical sampling, we produce two output rows at a time.
* We need a "spare" row buffer to hold the second output row if the
* application provides just a one-row buffer; we also use the spare
* to discard the dummy last row if the image height is odd.
*/
JSAMPROW spare_row;
boolean spare_full; /* T if spare buffer is occupied */
JDIMENSION out_row_width; /* samples per output row */
JDIMENSION rows_to_go; /* counts rows remaining in image */
} my_upsampler;
typedef my_upsampler * my_upsample_ptr;
#define SCALEBITS 16 /* speediest right-shift on some machines */
#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
/*
* Initialize tables for YCC->RGB colorspace conversion.
* This is taken directly from jdcolor.c; see that file for more info.
*/
LOCAL(void)
build_ycc_rgb_table (j_decompress_ptr cinfo)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
int i;
INT32 x;
SHIFT_TEMPS
upsample->Cr_r_tab = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(int));
upsample->Cb_b_tab = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(int));
upsample->Cr_g_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(INT32));
upsample->Cb_g_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(INT32));
for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
/* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
/* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
/* Cr=>R value is nearest int to 1.40200 * x */
upsample->Cr_r_tab[i] = (int)
RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
/* Cb=>B value is nearest int to 1.77200 * x */
upsample->Cb_b_tab[i] = (int)
RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
/* Cr=>G value is scaled-up -0.71414 * x */
upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x;
/* Cb=>G value is scaled-up -0.34414 * x */
/* We also add in ONE_HALF so that need not do it in inner loop */
upsample->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF;
}
}
/*
* Initialize for an upsampling pass.
*/
METHODDEF(void)
start_pass_merged_upsample (j_decompress_ptr cinfo)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
/* Mark the spare buffer empty */
upsample->spare_full = FALSE;
/* Initialize total-height counter for detecting bottom of image */
upsample->rows_to_go = cinfo->output_height;
}
/*
* Control routine to do upsampling (and color conversion).
*
* The control routine just handles the row buffering considerations.
*/
METHODDEF(void)
merged_2v_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
/* 2:1 vertical sampling case: may need a spare row. */
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
JSAMPROW work_ptrs[2];
JDIMENSION num_rows; /* number of rows returned to caller */
if (upsample->spare_full) {
/* If we have a spare row saved from a previous cycle, just return it. */
jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
1, upsample->out_row_width);
num_rows = 1;
upsample->spare_full = FALSE;
} else {
/* Figure number of rows to return to caller. */
num_rows = 2;
/* Not more than the distance to the end of the image. */
if (num_rows > upsample->rows_to_go)
num_rows = upsample->rows_to_go;
/* And not more than what the client can accept: */
out_rows_avail -= *out_row_ctr;
if (num_rows > out_rows_avail)
num_rows = out_rows_avail;
/* Create output pointer array for upsampler. */
work_ptrs[0] = output_buf[*out_row_ctr];
if (num_rows > 1) {
work_ptrs[1] = output_buf[*out_row_ctr + 1];
} else {
work_ptrs[1] = upsample->spare_row;
upsample->spare_full = TRUE;
}
/* Now do the upsampling. */
(*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs);
}
/* Adjust counts */
*out_row_ctr += num_rows;
upsample->rows_to_go -= num_rows;
/* When the buffer is emptied, declare this input row group consumed */
if (! upsample->spare_full)
(*in_row_group_ctr)++;
}
METHODDEF(void)
merged_1v_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
/* 1:1 vertical sampling case: much easier, never need a spare row. */
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
/* Just do the upsampling. */
(*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,
output_buf + *out_row_ctr);
/* Adjust counts */
(*out_row_ctr)++;
(*in_row_group_ctr)++;
}
/*
* These are the routines invoked by the control routines to do
* the actual upsampling/conversion. One row group is processed per call.
*
* Note: since we may be writing directly into application-supplied buffers,
* we have to be honest about the output width; we can't assume the buffer
* has been rounded up to an even width.
*/
/*
* Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
*/
METHODDEF(void)
h2v1_merged_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
JSAMPARRAY output_buf)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
register int y, cred, cgreen, cblue;
int cb, cr;
register JSAMPROW outptr;
JSAMPROW inptr0, inptr1, inptr2;
JDIMENSION col;
/* copy these pointers into registers if possible */
register JSAMPLE * range_limit = cinfo->sample_range_limit;
int * Crrtab = upsample->Cr_r_tab;
int * Cbbtab = upsample->Cb_b_tab;
INT32 * Crgtab = upsample->Cr_g_tab;
INT32 * Cbgtab = upsample->Cb_g_tab;
SHIFT_TEMPS
inptr0 = input_buf[0][in_row_group_ctr];
inptr1 = input_buf[1][in_row_group_ctr];
inptr2 = input_buf[2][in_row_group_ctr];
outptr = output_buf[0];
/* Loop for each pair of output pixels */
for (col = cinfo->output_width >> 1; col > 0; col--) {
/* Do the chroma part of the calculation */
cb = GETJSAMPLE(*inptr1++);
cr = GETJSAMPLE(*inptr2++);
cred = Crrtab[cr];
cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
cblue = Cbbtab[cb];
/* Fetch 2 Y values and emit 2 pixels */
y = GETJSAMPLE(*inptr0++);
outptr[RGB_RED] = range_limit[y + cred];
outptr[RGB_GREEN] = range_limit[y + cgreen];
outptr[RGB_BLUE] = range_limit[y + cblue];
outptr += RGB_PIXELSIZE;
y = GETJSAMPLE(*inptr0++);
outptr[RGB_RED] = range_limit[y + cred];
outptr[RGB_GREEN] = range_limit[y + cgreen];
outptr[RGB_BLUE] = range_limit[y + cblue];
outptr += RGB_PIXELSIZE;
}
/* If image width is odd, do the last output column separately */
if (cinfo->output_width & 1) {
cb = GETJSAMPLE(*inptr1);
cr = GETJSAMPLE(*inptr2);
cred = Crrtab[cr];
cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
cblue = Cbbtab[cb];
y = GETJSAMPLE(*inptr0);
outptr[RGB_RED] = range_limit[y + cred];
outptr[RGB_GREEN] = range_limit[y + cgreen];
outptr[RGB_BLUE] = range_limit[y + cblue];
}
}
/*
* Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
*/
METHODDEF(void)
h2v2_merged_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
JSAMPARRAY output_buf)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
register int y, cred, cgreen, cblue;
int cb, cr;
register JSAMPROW outptr0, outptr1;
JSAMPROW inptr00, inptr01, inptr1, inptr2;
JDIMENSION col;
/* copy these pointers into registers if possible */
register JSAMPLE * range_limit = cinfo->sample_range_limit;
int * Crrtab = upsample->Cr_r_tab;
int * Cbbtab = upsample->Cb_b_tab;
INT32 * Crgtab = upsample->Cr_g_tab;
INT32 * Cbgtab = upsample->Cb_g_tab;
SHIFT_TEMPS
inptr00 = input_buf[0][in_row_group_ctr*2];
inptr01 = input_buf[0][in_row_group_ctr*2 + 1];
inptr1 = input_buf[1][in_row_group_ctr];
inptr2 = input_buf[2][in_row_group_ctr];
outptr0 = output_buf[0];
outptr1 = output_buf[1];
/* Loop for each group of output pixels */
for (col = cinfo->output_width >> 1; col > 0; col--) {
/* Do the chroma part of the calculation */
cb = GETJSAMPLE(*inptr1++);
cr = GETJSAMPLE(*inptr2++);
cred = Crrtab[cr];
cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
cblue = Cbbtab[cb];
/* Fetch 4 Y values and emit 4 pixels */
y = GETJSAMPLE(*inptr00++);
outptr0[RGB_RED] = range_limit[y + cred];
outptr0[RGB_GREEN] = range_limit[y + cgreen];
outptr0[RGB_BLUE] = range_limit[y + cblue];
outptr0 += RGB_PIXELSIZE;
y = GETJSAMPLE(*inptr00++);
outptr0[RGB_RED] = range_limit[y + cred];
outptr0[RGB_GREEN] = range_limit[y + cgreen];
outptr0[RGB_BLUE] = range_limit[y + cblue];
outptr0 += RGB_PIXELSIZE;
y = GETJSAMPLE(*inptr01++);
outptr1[RGB_RED] = range_limit[y + cred];
outptr1[RGB_GREEN] = range_limit[y + cgreen];
outptr1[RGB_BLUE] = range_limit[y + cblue];
outptr1 += RGB_PIXELSIZE;
y = GETJSAMPLE(*inptr01++);
outptr1[RGB_RED] = range_limit[y + cred];
outptr1[RGB_GREEN] = range_limit[y + cgreen];
outptr1[RGB_BLUE] = range_limit[y + cblue];
outptr1 += RGB_PIXELSIZE;
}
/* If image width is odd, do the last output column separately */
if (cinfo->output_width & 1) {
cb = GETJSAMPLE(*inptr1);
cr = GETJSAMPLE(*inptr2);
cred = Crrtab[cr];
cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
cblue = Cbbtab[cb];
y = GETJSAMPLE(*inptr00);
outptr0[RGB_RED] = range_limit[y + cred];
outptr0[RGB_GREEN] = range_limit[y + cgreen];
outptr0[RGB_BLUE] = range_limit[y + cblue];
y = GETJSAMPLE(*inptr01);
outptr1[RGB_RED] = range_limit[y + cred];
outptr1[RGB_GREEN] = range_limit[y + cgreen];
outptr1[RGB_BLUE] = range_limit[y + cblue];
}
}
/*
* Module initialization routine for merged upsampling/color conversion.
*
* NB: this is called under the conditions determined by use_merged_upsample()
* in jdmaster.c. That routine MUST correspond to the actual capabilities
* of this module; no safety checks are made here.
*/
GLOBAL(void)
jinit_merged_upsampler (j_decompress_ptr cinfo)
{
my_upsample_ptr upsample;
upsample = (my_upsample_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_upsampler));
cinfo->upsample = (struct jpeg_upsampler *) upsample;
upsample->pub.start_pass = start_pass_merged_upsample;
upsample->pub.need_context_rows = FALSE;
upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;
if (cinfo->max_v_samp_factor == 2) {
upsample->pub.upsample = merged_2v_upsample;
upsample->upmethod = h2v2_merged_upsample;
/* Allocate a spare row buffer */
upsample->spare_row = (JSAMPROW)
(*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(size_t) (upsample->out_row_width * SIZEOF(JSAMPLE)));
} else {
upsample->pub.upsample = merged_1v_upsample;
upsample->upmethod = h2v1_merged_upsample;
/* No spare row needed */
upsample->spare_row = NULL;
}
build_ycc_rgb_table(cinfo);
}
#endif /* UPSAMPLE_MERGING_SUPPORTED */
--- NEW FILE: jcomapi.c ---
/*
* jcomapi.c
*
* Copyright (C) 1994-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains application interface routines that are used for both
* compression and decompression.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/*
* Abort processing of a JPEG compression or decompression operation,
* but don't destroy the object itself.
*
* For this, we merely clean up all the nonpermanent memory pools.
* Note that temp files (virtual arrays) are not allowed to belong to
* the permanent pool, so we will be able to close all temp files here.
* Closing a data source or destination, if necessary, is the application's
* responsibility.
*/
GLOBAL(void)
jpeg_abort (j_common_ptr cinfo)
{
int pool;
/* Do nothing if called on a not-initialized or destroyed JPEG object. */
if (cinfo->mem == NULL)
return;
/* Releasing pools in reverse order might help avoid fragmentation
* with some (brain-damaged) malloc libraries.
*/
for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
(*cinfo->mem->free_pool) (cinfo, pool);
}
/* Reset overall state for possible reuse of object */
if (cinfo->is_decompressor) {
cinfo->global_state = DSTATE_START;
/* Try to keep application from accessing now-deleted marker list.
* A bit kludgy to do it here, but this is the most central place.
*/
((j_decompress_ptr) cinfo)->marker_list = NULL;
} else {
cinfo->global_state = CSTATE_START;
}
}
/*
* Destruction of a JPEG object.
*
* Everything gets deallocated except the master jpeg_compress_struct itself
* and the error manager struct. Both of these are supplied by the application
* and must be freed, if necessary, by the application. (Often they are on
* the stack and so don't need to be freed anyway.)
* Closing a data source or destination, if necessary, is the application's
* responsibility.
*/
GLOBAL(void)
jpeg_destroy (j_common_ptr cinfo)
{
/* We need only tell the memory manager to release everything. */
/* NB: mem pointer is NULL if memory mgr failed to initialize. */
if (cinfo->mem != NULL)
(*cinfo->mem->self_destruct) (cinfo);
cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */
cinfo->global_state = 0; /* mark it destroyed */
}
/*
* Convenience routines for allocating quantization and Huffman tables.
* (Would jutils.c be a more reasonable place to put these?)
*/
GLOBAL(JQUANT_TBL *)
jpeg_alloc_quant_table (j_common_ptr cinfo)
{
JQUANT_TBL *tbl;
tbl = (JQUANT_TBL *)
(*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
tbl->sent_table = FALSE; /* make sure this is false in any new table */
return tbl;
}
GLOBAL(JHUFF_TBL *)
jpeg_alloc_huff_table (j_common_ptr cinfo)
{
JHUFF_TBL *tbl;
tbl = (JHUFF_TBL *)
(*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
tbl->sent_table = FALSE; /* make sure this is false in any new table */
return tbl;
}
--- NEW FILE: jutils.c ---
/*
* jutils.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains tables and miscellaneous utility routines needed
* for both compression and decompression.
* Note we prefix all global names with "j" to minimize conflicts with
* a surrounding application.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/*
* jpeg_zigzag_order[i] is the zigzag-order position of the i'th element
* of a DCT block read in natural order (left to right, top to bottom).
*/
#if 0 /* This table is not actually needed in v6a */
const int jpeg_zigzag_order[DCTSIZE2] = {
0, 1, 5, 6, 14, 15, 27, 28,
2, 4, 7, 13, 16, 26, 29, 42,
3, 8, 12, 17, 25, 30, 41, 43,
9, 11, 18, 24, 31, 40, 44, 53,
10, 19, 23, 32, 39, 45, 52, 54,
20, 22, 33, 38, 46, 51, 55, 60,
21, 34, 37, 47, 50, 56, 59, 61,
35, 36, 48, 49, 57, 58, 62, 63
};
#endif
/*
* jpeg_natural_order[i] is the natural-order position of the i'th element
* of zigzag order.
*
* When reading corrupted data, the Huffman decoders could attempt
* to reference an entry beyond the end of this array (if the decoded
* zero run length reaches past the end of the block). To prevent
* wild stores without adding an inner-loop test, we put some extra
* "63"s after the real entries. This will cause the extra coefficient
* to be stored in location 63 of the block, not somewhere random.
* The worst case would be a run-length of 15, which means we need 16
* fake entries.
*/
const int jpeg_natural_order[DCTSIZE2+16] = {
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63,
63, 63, 63, 63, 63, 63, 63, 63, /* extra entries for safety in decoder */
63, 63, 63, 63, 63, 63, 63, 63
};
/*
* Arithmetic utilities
*/
GLOBAL(long)
jdiv_round_up (long a, long b)
/* Compute a/b rounded up to next integer, ie, ceil(a/b) */
/* Assumes a >= 0, b > 0 */
{
return (a + b - 1L) / b;
}
GLOBAL(long)
jround_up (long a, long b)
/* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
/* Assumes a >= 0, b > 0 */
{
a += b - 1L;
return a - (a % b);
}
/* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
* and coefficient-block arrays. This won't work on 80x86 because the arrays
* are FAR and we're assuming a small-pointer memory model. However, some
* DOS compilers provide far-pointer versions of memcpy() and memset() even
* in the small-model libraries. These will be used if USE_FMEM is defined.
* Otherwise, the routines below do it the hard way. (The performance cost
* is not all that great, because these routines aren't very heavily used.)
*/
#ifndef NEED_FAR_POINTERS /* normal case, same as regular macros */
#define FMEMCOPY(dest,src,size) MEMCOPY(dest,src,size)
#define FMEMZERO(target,size) MEMZERO(target,size)
#else /* 80x86 case, define if we can */
#ifdef USE_FMEM
#define FMEMCOPY(dest,src,size) _fmemcpy((void FAR *)(dest), (const void FAR *)(src), (size_t)(size))
#define FMEMZERO(target,size) _fmemset((void FAR *)(target), 0, (size_t)(size))
#endif
#endif
GLOBAL(void)
jcopy_sample_rows (JSAMPARRAY input_array, int source_row,
JSAMPARRAY output_array, int dest_row,
int num_rows, JDIMENSION num_cols)
/* Copy some rows of samples from one place to another.
* num_rows rows are copied from input_array[source_row++]
* to output_array[dest_row++]; these areas may overlap for duplication.
* The source and destination arrays must be at least as wide as num_cols.
*/
{
register JSAMPROW inptr, outptr;
#ifdef FMEMCOPY
register size_t count = (size_t) (num_cols * SIZEOF(JSAMPLE));
#else
register JDIMENSION count;
#endif
register int row;
input_array += source_row;
output_array += dest_row;
for (row = num_rows; row > 0; row--) {
inptr = *input_array++;
outptr = *output_array++;
#ifdef FMEMCOPY
FMEMCOPY(outptr, inptr, count);
#else
for (count = num_cols; count > 0; count--)
*outptr++ = *inptr++; /* needn't bother with GETJSAMPLE() here */
#endif
}
}
GLOBAL(void)
jcopy_block_row (JBLOCKROW input_row, JBLOCKROW output_row,
JDIMENSION num_blocks)
/* Copy a row of coefficient blocks from one place to another. */
{
#ifdef FMEMCOPY
FMEMCOPY(output_row, input_row, num_blocks * (DCTSIZE2 * SIZEOF(JCOEF)));
#else
register JCOEFPTR inptr, outptr;
register long count;
inptr = (JCOEFPTR) input_row;
outptr = (JCOEFPTR) output_row;
for (count = (long) num_blocks * DCTSIZE2; count > 0; count--) {
*outptr++ = *inptr++;
}
#endif
}
GLOBAL(void)
jzero_far (void FAR * target, size_t bytestozero)
/* Zero out a chunk of FAR memory. */
/* This might be sample-array data, block-array data, or alloc_large data. */
{
#ifdef FMEMZERO
FMEMZERO(target, bytestozero);
#else
register char FAR * ptr = (char FAR *) target;
register size_t count;
for (count = bytestozero; count > 0; count--) {
*ptr++ = 0;
}
#endif
}
--- NEW FILE: jdapistd.c ---
/*
* jdapistd.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains application interface code for the decompression half
* of the JPEG library. These are the "standard" API routines that are
* used in the normal full-decompression case. They are not used by a
* transcoding-only application. Note that if an application links in
* jpeg_start_decompress, it will end up linking in the entire decompressor.
* We thus must separate this file from jdapimin.c to avoid linking the
* whole decompression library into a transcoder.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Forward declarations */
LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));
/*
* Decompression initialization.
* jpeg_read_header must be completed before calling this.
*
* If a multipass operating mode was selected, this will do all but the
* last pass, and thus may take a great deal of time.
*
* Returns FALSE if suspended. The return value need be inspected only if
* a suspending data source is used.
*/
GLOBAL(boolean)
jpeg_start_decompress (j_decompress_ptr cinfo)
{
if (cinfo->global_state == DSTATE_READY) {
/* First call: initialize master control, select active modules */
jinit_master_decompress(cinfo);
if (cinfo->buffered_image) {
/* No more work here; expecting jpeg_start_output next */
cinfo->global_state = DSTATE_BUFIMAGE;
return TRUE;
}
cinfo->global_state = DSTATE_PRELOAD;
}
if (cinfo->global_state == DSTATE_PRELOAD) {
/* If file has multiple scans, absorb them all into the coef buffer */
if (cinfo->inputctl->has_multiple_scans) {
#ifdef D_MULTISCAN_FILES_SUPPORTED
for (;;) {
int retcode;
/* Call progress monitor hook if present */
if (cinfo->progress != NULL)
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
/* Absorb some more input */
retcode = (*cinfo->inputctl->consume_input) (cinfo);
if (retcode == JPEG_SUSPENDED)
return FALSE;
if (retcode == JPEG_REACHED_EOI)
break;
/* Advance progress counter if appropriate */
if (cinfo->progress != NULL &&
(retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
/* jdmaster underestimated number of scans; ratchet up one scan */
cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
}
}
}
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* D_MULTISCAN_FILES_SUPPORTED */
}
cinfo->output_scan_number = cinfo->input_scan_number;
} else if (cinfo->global_state != DSTATE_PRESCAN)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
/* Perform any dummy output passes, and set up for the final pass */
return output_pass_setup(cinfo);
}
/*
* Set up for an output pass, and perform any dummy pass(es) needed.
* Common subroutine for jpeg_start_decompress and jpeg_start_output.
* Entry: global_state = DSTATE_PRESCAN only if previously suspended.
* Exit: If done, returns TRUE and sets global_state for proper output mode.
* If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
*/
LOCAL(boolean)
output_pass_setup (j_decompress_ptr cinfo)
{
if (cinfo->global_state != DSTATE_PRESCAN) {
/* First call: do pass setup */
(*cinfo->master->prepare_for_output_pass) (cinfo);
cinfo->output_scanline = 0;
cinfo->global_state = DSTATE_PRESCAN;
}
/* Loop over any required dummy passes */
while (cinfo->master->is_dummy_pass) {
#ifdef QUANT_2PASS_SUPPORTED
/* Crank through the dummy pass */
while (cinfo->output_scanline < cinfo->output_height) {
JDIMENSION last_scanline;
/* Call progress monitor hook if present */
if (cinfo->progress != NULL) {
cinfo->progress->pass_counter = (long) cinfo->output_scanline;
cinfo->progress->pass_limit = (long) cinfo->output_height;
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
}
/* Process some data */
last_scanline = cinfo->output_scanline;
(*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
&cinfo->output_scanline, (JDIMENSION) 0);
if (cinfo->output_scanline == last_scanline)
return FALSE; /* No progress made, must suspend */
}
/* Finish up dummy pass, and set up for another one */
(*cinfo->master->finish_output_pass) (cinfo);
(*cinfo->master->prepare_for_output_pass) (cinfo);
cinfo->output_scanline = 0;
#else
ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif /* QUANT_2PASS_SUPPORTED */
}
/* Ready for application to drive output pass through
* jpeg_read_scanlines or jpeg_read_raw_data.
*/
cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
return TRUE;
}
/*
* Read some scanlines of data from the JPEG decompressor.
*
* The return value will be the number of lines actually read.
* This may be less than the number requested in several cases,
* including bottom of image, data source suspension, and operating
* modes that emit multiple scanlines at a time.
*
* Note: we warn about excess calls to jpeg_read_scanlines() since
* this likely signals an application programmer error. However,
* an oversize buffer (max_lines > scanlines remaining) is not an error.
*/
GLOBAL(JDIMENSION)
jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
JDIMENSION max_lines)
{
JDIMENSION row_ctr;
if (cinfo->global_state != DSTATE_SCANNING)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
if (cinfo->output_scanline >= cinfo->output_height) {
WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
return 0;
}
/* Call progress monitor hook if present */
if (cinfo->progress != NULL) {
cinfo->progress->pass_counter = (long) cinfo->output_scanline;
cinfo->progress->pass_limit = (long) cinfo->output_height;
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
}
/* Process some data */
row_ctr = 0;
(*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
cinfo->output_scanline += row_ctr;
return row_ctr;
}
/*
* Alternate entry point to read raw data.
* Processes exactly one iMCU row per call, unless suspended.
*/
GLOBAL(JDIMENSION)
jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
JDIMENSION max_lines)
{
JDIMENSION lines_per_iMCU_row;
if (cinfo->global_state != DSTATE_RAW_OK)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
if (cinfo->output_scanline >= cinfo->output_height) {
WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
return 0;
}
/* Call progress monitor hook if present */
if (cinfo->progress != NULL) {
cinfo->progress->pass_counter = (long) cinfo->output_scanline;
cinfo->progress->pass_limit = (long) cinfo->output_height;
(*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
}
/* Verify that at least one iMCU row can be returned. */
lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size;
if (max_lines < lines_per_iMCU_row)
ERREXIT(cinfo, JERR_BUFFER_SIZE);
/* Decompress directly into user's buffer. */
if (! (*cinfo->coef->decompress_data) (cinfo, data))
return 0; /* suspension forced, can do nothing more */
/* OK, we processed one iMCU row. */
cinfo->output_scanline += lines_per_iMCU_row;
return lines_per_iMCU_row;
}
/* Additional entry points for buffered-image mode. */
#ifdef D_MULTISCAN_FILES_SUPPORTED
/*
* Initialize for an output pass in buffered-image mode.
*/
GLOBAL(boolean)
jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
{
if (cinfo->global_state != DSTATE_BUFIMAGE &&
cinfo->global_state != DSTATE_PRESCAN)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
/* Limit scan number to valid range */
if (scan_number <= 0)
scan_number = 1;
if (cinfo->inputctl->eoi_reached &&
scan_number > cinfo->input_scan_number)
scan_number = cinfo->input_scan_number;
cinfo->output_scan_number = scan_number;
/* Perform any dummy output passes, and set up for the real pass */
return output_pass_setup(cinfo);
}
/*
* Finish up after an output pass in buffered-image mode.
*
* Returns FALSE if suspended. The return value need be inspected only if
* a suspending data source is used.
*/
GLOBAL(boolean)
jpeg_finish_output (j_decompress_ptr cinfo)
{
if ((cinfo->global_state == DSTATE_SCANNING ||
cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
/* Terminate this pass. */
/* We do not require the whole pass to have been completed. */
(*cinfo->master->finish_output_pass) (cinfo);
cinfo->global_state = DSTATE_BUFPOST;
} else if (cinfo->global_state != DSTATE_BUFPOST) {
/* BUFPOST = repeat call after a suspension, anything else is error */
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
}
/* Read markers looking for SOS or EOI */
while (cinfo->input_scan_number <= cinfo->output_scan_number &&
! cinfo->inputctl->eoi_reached) {
if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
return FALSE; /* Suspend, come back later */
}
cinfo->global_state = DSTATE_BUFIMAGE;
return TRUE;
}
#endif /* D_MULTISCAN_FILES_SUPPORTED */
--- NEW FILE: jdphuff.c ---
/*
* jdphuff.c
*
* Copyright (C) 1995-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains Huffman entropy decoding routines for progressive JPEG.
*
* Much of the complexity here has to do with supporting input suspension.
* If the data source module demands suspension, we want to be able to back
* up to the start of the current MCU. To do this, we copy state variables
* into local working storage, and update them back to the permanent
* storage only upon successful completion of an MCU.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdhuff.h" /* Declarations shared with jdhuff.c */
#ifdef D_PROGRESSIVE_SUPPORTED
/*
* Expanded entropy decoder object for progressive Huffman decoding.
*
* The savable_state subrecord contains fields that change within an MCU,
* but must not be updated permanently until we complete the MCU.
*/
typedef struct {
unsigned int EOBRUN; /* remaining EOBs in EOBRUN */
int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
} savable_state;
/* This macro is to work around compilers with missing or broken
* structure assignment. You'll need to fix this code if you have
* such a compiler and you change MAX_COMPS_IN_SCAN.
*/
#ifndef NO_STRUCT_ASSIGN
#define ASSIGN_STATE(dest,src) ((dest) = (src))
#else
#if MAX_COMPS_IN_SCAN == 4
#define ASSIGN_STATE(dest,src) \
((dest).EOBRUN = (src).EOBRUN, \
(dest).last_dc_val[0] = (src).last_dc_val[0], \
(dest).last_dc_val[1] = (src).last_dc_val[1], \
(dest).last_dc_val[2] = (src).last_dc_val[2], \
(dest).last_dc_val[3] = (src).last_dc_val[3])
#endif
#endif
typedef struct {
struct jpeg_entropy_decoder pub; /* public fields */
/* These fields are loaded into local variables at start of each MCU.
* In case of suspension, we exit WITHOUT updating them.
*/
bitread_perm_state bitstate; /* Bit buffer at start of MCU */
savable_state saved; /* Other state at start of MCU */
/* These fields are NOT loaded into local working state. */
unsigned int restarts_to_go; /* MCUs left in this restart interval */
/* Pointers to derived tables (these workspaces have image lifespan) */
d_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */
} phuff_entropy_decoder;
typedef phuff_entropy_decoder * phuff_entropy_ptr;
/* Forward declarations */
METHODDEF(boolean) decode_mcu_DC_first JPP((j_decompress_ptr cinfo,
JBLOCKROW *MCU_data));
METHODDEF(boolean) decode_mcu_AC_first JPP((j_decompress_ptr cinfo,
JBLOCKROW *MCU_data));
METHODDEF(boolean) decode_mcu_DC_refine JPP((j_decompress_ptr cinfo,
JBLOCKROW *MCU_data));
METHODDEF(boolean) decode_mcu_AC_refine JPP((j_decompress_ptr cinfo,
JBLOCKROW *MCU_data));
/*
* Initialize for a Huffman-compressed scan.
*/
METHODDEF(void)
start_pass_phuff_decoder (j_decompress_ptr cinfo)
{
phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
boolean is_DC_band, bad;
int ci, coefi, tbl;
int *coef_bit_ptr;
jpeg_component_info * compptr;
is_DC_band = (cinfo->Ss == 0);
/* Validate scan parameters */
bad = FALSE;
if (is_DC_band) {
if (cinfo->Se != 0)
bad = TRUE;
} else {
/* need not check Ss/Se < 0 since they came from unsigned bytes */
if (cinfo->Ss > cinfo->Se || cinfo->Se >= DCTSIZE2)
bad = TRUE;
/* AC scans may have only one component */
if (cinfo->comps_in_scan != 1)
bad = TRUE;
}
if (cinfo->Ah != 0) {
/* Successive approximation refinement scan: must have Al = Ah-1. */
if (cinfo->Al != cinfo->Ah-1)
bad = TRUE;
}
if (cinfo->Al > 13) /* need not check for < 0 */
bad = TRUE;
/* Arguably the maximum Al value should be less than 13 for 8-bit precision,
* but the spec doesn't say so, and we try to be liberal about what we
* accept. Note: large Al values could result in out-of-range DC
* coefficients during early scans, leading to bizarre displays due to
* overflows in the IDCT math. But we won't crash.
*/
if (bad)
ERREXIT4(cinfo, JERR_BAD_PROGRESSION,
cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al);
/* Update progression status, and verify that scan order is legal.
* Note that inter-scan inconsistencies are treated as warnings
* not fatal errors ... not clear if this is right way to behave.
*/
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
int cindex = cinfo->cur_comp_info[ci]->component_index;
coef_bit_ptr = & cinfo->coef_bits[cindex][0];
if (!is_DC_band && coef_bit_ptr[0] < 0) /* AC without prior DC scan */
WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);
for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {
int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];
if (cinfo->Ah != expected)
WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);
coef_bit_ptr[coefi] = cinfo->Al;
}
}
/* Select MCU decoding routine */
if (cinfo->Ah == 0) {
if (is_DC_band)
entropy->pub.decode_mcu = decode_mcu_DC_first;
else
entropy->pub.decode_mcu = decode_mcu_AC_first;
} else {
if (is_DC_band)
entropy->pub.decode_mcu = decode_mcu_DC_refine;
else
entropy->pub.decode_mcu = decode_mcu_AC_refine;
}
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
/* Make sure requested tables are present, and compute derived tables.
* We may build same derived table more than once, but it's not expensive.
*/
if (is_DC_band) {
if (cinfo->Ah == 0) { /* DC refinement needs no table */
tbl = compptr->dc_tbl_no;
jpeg_make_d_derived_tbl(cinfo, TRUE, tbl,
& entropy->derived_tbls[tbl]);
}
} else {
tbl = compptr->ac_tbl_no;
jpeg_make_d_derived_tbl(cinfo, FALSE, tbl,
& entropy->derived_tbls[tbl]);
/* remember the single active table */
entropy->ac_derived_tbl = entropy->derived_tbls[tbl];
}
/* Initialize DC predictions to 0 */
entropy->saved.last_dc_val[ci] = 0;
}
/* Initialize bitread state variables */
entropy->bitstate.bits_left = 0;
entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */
entropy->pub.insufficient_data = FALSE;
/* Initialize private state variables */
entropy->saved.EOBRUN = 0;
/* Initialize restart counter */
entropy->restarts_to_go = cinfo->restart_interval;
}
/*
* Figure F.12: extend sign bit.
* On some machines, a shift and add will be faster than a table lookup.
*/
#ifdef AVOID_TABLES
#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x))
#else
#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
static const int extend_test[16] = /* entry n is 2**(n-1) */
{ 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
{ 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 };
#endif /* AVOID_TABLES */
/*
* Check for a restart marker & resynchronize decoder.
* Returns FALSE if must suspend.
*/
LOCAL(boolean)
process_restart (j_decompress_ptr cinfo)
{
phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
int ci;
/* Throw away any unused bits remaining in bit buffer; */
/* include any full bytes in next_marker's count of discarded bytes */
cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
entropy->bitstate.bits_left = 0;
/* Advance past the RSTn marker */
if (! (*cinfo->marker->read_restart_marker) (cinfo))
return FALSE;
/* Re-initialize DC predictions to 0 */
for (ci = 0; ci < cinfo->comps_in_scan; ci++)
entropy->saved.last_dc_val[ci] = 0;
/* Re-init EOB run count, too */
entropy->saved.EOBRUN = 0;
/* Reset restart counter */
entropy->restarts_to_go = cinfo->restart_interval;
/* Reset out-of-data flag, unless read_restart_marker left us smack up
* against a marker. In that case we will end up treating the next data
* segment as empty, and we can avoid producing bogus output pixels by
* leaving the flag set.
*/
if (cinfo->unread_marker == 0)
entropy->pub.insufficient_data = FALSE;
return TRUE;
}
/*
* Huffman MCU decoding.
* Each of these routines decodes and returns one MCU's worth of
* Huffman-compressed coefficients.
* The coefficients are reordered from zigzag order into natural array order,
* but are not dequantized.
*
* The i'th block of the MCU is stored into the block pointed to by
* MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.
*
* We return FALSE if data source requested suspension. In that case no
* changes have been made to permanent state. (Exception: some output
* coefficients may already have been assigned. This is harmless for
* spectral selection, since we'll just re-assign them on the next call.
* Successive approximation AC refinement has to be more careful, however.)
*/
/*
* MCU decoding for DC initial scan (either spectral selection,
* or first pass of successive approximation).
*/
METHODDEF(boolean)
decode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
int Al = cinfo->Al;
register int s, r;
int blkn, ci;
JBLOCKROW block;
BITREAD_STATE_VARS;
savable_state state;
d_derived_tbl * tbl;
jpeg_component_info * compptr;
/* Process restart marker if needed; may have to suspend */
if (cinfo->restart_interval) {
if (entropy->restarts_to_go == 0)
if (! process_restart(cinfo))
return FALSE;
}
/* If we've run out of data, just leave the MCU set to zeroes.
* This way, we return uniform gray for the remainder of the segment.
*/
if (! entropy->pub.insufficient_data) {
/* Load up working state */
BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
ASSIGN_STATE(state, entropy->saved);
/* Outer loop handles each block in the MCU */
for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
block = MCU_data[blkn];
ci = cinfo->MCU_membership[blkn];
compptr = cinfo->cur_comp_info[ci];
tbl = entropy->derived_tbls[compptr->dc_tbl_no];
/* Decode a single block's worth of coefficients */
/* Section F.2.2.1: decode the DC coefficient difference */
HUFF_DECODE(s, br_state, tbl, return FALSE, label1);
if (s) {
CHECK_BIT_BUFFER(br_state, s, return FALSE);
r = GET_BITS(s);
s = HUFF_EXTEND(r, s);
}
/* Convert DC difference to actual value, update last_dc_val */
s += state.last_dc_val[ci];
state.last_dc_val[ci] = s;
/* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */
(*block)[0] = (JCOEF) (s << Al);
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
ASSIGN_STATE(entropy->saved, state);
}
/* Account for restart interval (no-op if not using restarts) */
entropy->restarts_to_go--;
return TRUE;
}
/*
* MCU decoding for AC initial scan (either spectral selection,
* or first pass of successive approximation).
*/
METHODDEF(boolean)
decode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
int Se = cinfo->Se;
int Al = cinfo->Al;
register int s, k, r;
unsigned int EOBRUN;
JBLOCKROW block;
BITREAD_STATE_VARS;
d_derived_tbl * tbl;
/* Process restart marker if needed; may have to suspend */
if (cinfo->restart_interval) {
if (entropy->restarts_to_go == 0)
if (! process_restart(cinfo))
return FALSE;
}
/* If we've run out of data, just leave the MCU set to zeroes.
* This way, we return uniform gray for the remainder of the segment.
*/
if (! entropy->pub.insufficient_data) {
/* Load up working state.
* We can avoid loading/saving bitread state if in an EOB run.
*/
EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
/* There is always only one block per MCU */
if (EOBRUN > 0) /* if it's a band of zeroes... */
EOBRUN--; /* ...process it now (we do nothing) */
else {
BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
block = MCU_data[0];
tbl = entropy->ac_derived_tbl;
for (k = cinfo->Ss; k <= Se; k++) {
HUFF_DECODE(s, br_state, tbl, return FALSE, label2);
r = s >> 4;
s &= 15;
if (s) {
k += r;
CHECK_BIT_BUFFER(br_state, s, return FALSE);
r = GET_BITS(s);
s = HUFF_EXTEND(r, s);
/* Scale and output coefficient in natural (dezigzagged) order */
(*block)[jpeg_natural_order[k]] = (JCOEF) (s << Al);
} else {
if (r == 15) { /* ZRL */
k += 15; /* skip 15 zeroes in band */
} else { /* EOBr, run length is 2^r + appended bits */
EOBRUN = 1 << r;
if (r) { /* EOBr, r > 0 */
CHECK_BIT_BUFFER(br_state, r, return FALSE);
r = GET_BITS(r);
EOBRUN += r;
}
EOBRUN--; /* this band is processed at this moment */
break; /* force end-of-band */
}
}
}
BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
}
/* Completed MCU, so update state */
entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
}
/* Account for restart interval (no-op if not using restarts) */
entropy->restarts_to_go--;
return TRUE;
}
/*
* MCU decoding for DC successive approximation refinement scan.
* Note: we assume such scans can be multi-component, although the spec
* is not very clear on the point.
*/
METHODDEF(boolean)
decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
int blkn;
JBLOCKROW block;
BITREAD_STATE_VARS;
/* Process restart marker if needed; may have to suspend */
if (cinfo->restart_interval) {
if (entropy->restarts_to_go == 0)
if (! process_restart(cinfo))
return FALSE;
}
/* Not worth the cycles to check insufficient_data here,
* since we will not change the data anyway if we read zeroes.
*/
/* Load up working state */
BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
/* Outer loop handles each block in the MCU */
for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
block = MCU_data[blkn];
/* Encoded data is simply the next bit of the two's-complement DC value */
CHECK_BIT_BUFFER(br_state, 1, return FALSE);
if (GET_BITS(1))
(*block)[0] |= p1;
/* Note: since we use |=, repeating the assignment later is safe */
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
/* Account for restart interval (no-op if not using restarts) */
entropy->restarts_to_go--;
return TRUE;
}
/*
* MCU decoding for AC successive approximation refinement scan.
*/
METHODDEF(boolean)
decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
int Se = cinfo->Se;
int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
int m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */
register int s, k, r;
unsigned int EOBRUN;
JBLOCKROW block;
JCOEFPTR thiscoef;
BITREAD_STATE_VARS;
d_derived_tbl * tbl;
int num_newnz;
int newnz_pos[DCTSIZE2];
/* Process restart marker if needed; may have to suspend */
if (cinfo->restart_interval) {
if (entropy->restarts_to_go == 0)
if (! process_restart(cinfo))
return FALSE;
}
/* If we've run out of data, don't modify the MCU.
*/
if (! entropy->pub.insufficient_data) {
/* Load up working state */
BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
/* There is always only one block per MCU */
block = MCU_data[0];
tbl = entropy->ac_derived_tbl;
/* If we are forced to suspend, we must undo the assignments to any newly
* nonzero coefficients in the block, because otherwise we'd get confused
* next time about which coefficients were already nonzero.
* But we need not undo addition of bits to already-nonzero coefficients;
* instead, we can test the current bit to see if we already did it.
*/
num_newnz = 0;
/* initialize coefficient loop counter to start of band */
k = cinfo->Ss;
if (EOBRUN == 0) {
for (; k <= Se; k++) {
HUFF_DECODE(s, br_state, tbl, goto undoit, label3);
r = s >> 4;
s &= 15;
if (s) {
if (s != 1) /* size of new coef should always be 1 */
WARNMS(cinfo, JWRN_HUFF_BAD_CODE);
CHECK_BIT_BUFFER(br_state, 1, goto undoit);
if (GET_BITS(1))
s = p1; /* newly nonzero coef is positive */
else
s = m1; /* newly nonzero coef is negative */
} else {
if (r != 15) {
EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */
if (r) {
CHECK_BIT_BUFFER(br_state, r, goto undoit);
r = GET_BITS(r);
EOBRUN += r;
}
break; /* rest of block is handled by EOB logic */
}
/* note s = 0 for processing ZRL */
}
/* Advance over already-nonzero coefs and r still-zero coefs,
* appending correction bits to the nonzeroes. A correction bit is 1
* if the absolute value of the coefficient must be increased.
*/
do {
thiscoef = *block + jpeg_natural_order[k];
if (*thiscoef != 0) {
CHECK_BIT_BUFFER(br_state, 1, goto undoit);
if (GET_BITS(1)) {
if ((*thiscoef & p1) == 0) { /* do nothing if already set it */
if (*thiscoef >= 0)
*thiscoef += p1;
else
*thiscoef += m1;
}
}
} else {
if (--r < 0)
break; /* reached target zero coefficient */
}
k++;
} while (k <= Se);
if (s) {
int pos = jpeg_natural_order[k];
/* Output newly nonzero coefficient */
(*block)[pos] = (JCOEF) s;
/* Remember its position in case we have to suspend */
newnz_pos[num_newnz++] = pos;
}
}
}
if (EOBRUN > 0) {
/* Scan any remaining coefficient positions after the end-of-band
* (the last newly nonzero coefficient, if any). Append a correction
* bit to each already-nonzero coefficient. A correction bit is 1
* if the absolute value of the coefficient must be increased.
*/
for (; k <= Se; k++) {
thiscoef = *block + jpeg_natural_order[k];
if (*thiscoef != 0) {
CHECK_BIT_BUFFER(br_state, 1, goto undoit);
if (GET_BITS(1)) {
if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */
if (*thiscoef >= 0)
*thiscoef += p1;
else
*thiscoef += m1;
}
}
}
}
/* Count one block completed in EOB run */
EOBRUN--;
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
}
/* Account for restart interval (no-op if not using restarts) */
entropy->restarts_to_go--;
return TRUE;
undoit:
/* Re-zero any output coefficients that we made newly nonzero */
while (num_newnz > 0)
(*block)[newnz_pos[--num_newnz]] = 0;
return FALSE;
}
/*
* Module initialization routine for progressive Huffman entropy decoding.
*/
GLOBAL(void)
jinit_phuff_decoder (j_decompress_ptr cinfo)
{
phuff_entropy_ptr entropy;
int *coef_bit_ptr;
int ci, i;
entropy = (phuff_entropy_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(phuff_entropy_decoder));
cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
entropy->pub.start_pass = start_pass_phuff_decoder;
/* Mark derived tables unallocated */
for (i = 0; i < NUM_HUFF_TBLS; i++) {
entropy->derived_tbls[i] = NULL;
}
/* Create progression status table */
cinfo->coef_bits = (int (*)[DCTSIZE2])
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->num_components*DCTSIZE2*SIZEOF(int));
coef_bit_ptr = & cinfo->coef_bits[0][0];
for (ci = 0; ci < cinfo->num_components; ci++)
for (i = 0; i < DCTSIZE2; i++)
*coef_bit_ptr++ = -1;
}
#endif /* D_PROGRESSIVE_SUPPORTED */
--- NEW FILE: jdcolor.c ---
/*
* jdcolor.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains output colorspace conversion routines.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Private subobject */
typedef struct {
struct jpeg_color_deconverter pub; /* public fields */
/* Private state for YCC->RGB conversion */
int * Cr_r_tab; /* => table for Cr to R conversion */
int * Cb_b_tab; /* => table for Cb to B conversion */
INT32 * Cr_g_tab; /* => table for Cr to G conversion */
INT32 * Cb_g_tab; /* => table for Cb to G conversion */
} my_color_deconverter;
typedef my_color_deconverter * my_cconvert_ptr;
/**************** YCbCr -> RGB conversion: most common case **************/
/*
* YCbCr is defined per CCIR 601-1, except that Cb and Cr are
* normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
* The conversion equations to be implemented are therefore
* R = Y + 1.40200 * Cr
* G = Y - 0.34414 * Cb - 0.71414 * Cr
* B = Y + 1.77200 * Cb
* where Cb and Cr represent the incoming values less CENTERJSAMPLE.
* (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
*
* To avoid floating-point arithmetic, we represent the fractional constants
* as integers scaled up by 2^16 (about 4 digits precision); we have to divide
* the products by 2^16, with appropriate rounding, to get the correct answer.
* Notice that Y, being an integral input, does not contribute any fraction
* so it need not participate in the rounding.
*
* For even more speed, we avoid doing any multiplications in the inner loop
* by precalculating the constants times Cb and Cr for all possible values.
* For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
* for 12-bit samples it is still acceptable. It's not very reasonable for
* 16-bit samples, but if you want lossless storage you shouldn't be changing
* colorspace anyway.
* The Cr=>R and Cb=>B values can be rounded to integers in advance; the
* values for the G calculation are left scaled up, since we must add them
* together before rounding.
*/
#define SCALEBITS 16 /* speediest right-shift on some machines */
#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
/*
* Initialize tables for YCC->RGB colorspace conversion.
*/
LOCAL(void)
build_ycc_rgb_table (j_decompress_ptr cinfo)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
int i;
INT32 x;
SHIFT_TEMPS
cconvert->Cr_r_tab = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(int));
cconvert->Cb_b_tab = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(int));
cconvert->Cr_g_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(INT32));
cconvert->Cb_g_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(MAXJSAMPLE+1) * SIZEOF(INT32));
for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
/* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
/* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
/* Cr=>R value is nearest int to 1.40200 * x */
cconvert->Cr_r_tab[i] = (int)
RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
/* Cb=>B value is nearest int to 1.77200 * x */
cconvert->Cb_b_tab[i] = (int)
RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
/* Cr=>G value is scaled-up -0.71414 * x */
cconvert->Cr_g_tab[i] = (- FIX(0.71414)) * x;
/* Cb=>G value is scaled-up -0.34414 * x */
/* We also add in ONE_HALF so that need not do it in inner loop */
cconvert->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF;
}
}
/*
* Convert some rows of samples to the output colorspace.
*
* Note that we change from noninterleaved, one-plane-per-component format
* to interleaved-pixel format. The output buffer is therefore three times
* as wide as the input buffer.
* A starting row offset is provided only for the input buffer. The caller
* can easily adjust the passed output_buf value to accommodate any row
* offset required on that side.
*/
METHODDEF(void)
ycc_rgb_convert (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
register int y, cb, cr;
register JSAMPROW outptr;
register JSAMPROW inptr0, inptr1, inptr2;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->output_width;
/* copy these pointers into registers if possible */
register JSAMPLE * range_limit = cinfo->sample_range_limit;
register int * Crrtab = cconvert->Cr_r_tab;
register int * Cbbtab = cconvert->Cb_b_tab;
register INT32 * Crgtab = cconvert->Cr_g_tab;
register INT32 * Cbgtab = cconvert->Cb_g_tab;
SHIFT_TEMPS
while (--num_rows >= 0) {
inptr0 = input_buf[0][input_row];
inptr1 = input_buf[1][input_row];
inptr2 = input_buf[2][input_row];
input_row++;
outptr = *output_buf++;
for (col = 0; col < num_cols; col++) {
y = GETJSAMPLE(inptr0[col]);
cb = GETJSAMPLE(inptr1[col]);
cr = GETJSAMPLE(inptr2[col]);
/* Range-limiting is essential due to noise introduced by DCT losses. */
outptr[RGB_RED] = range_limit[y + Crrtab[cr]];
outptr[RGB_GREEN] = range_limit[y +
((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
SCALEBITS))];
outptr[RGB_BLUE] = range_limit[y + Cbbtab[cb]];
outptr += RGB_PIXELSIZE;
}
}
}
/**************** Cases other than YCbCr -> RGB **************/
/*
* Color conversion for no colorspace change: just copy the data,
* converting from separate-planes to interleaved representation.
*/
METHODDEF(void)
null_convert (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows)
{
register JSAMPROW inptr, outptr;
register JDIMENSION count;
register int num_components = cinfo->num_components;
JDIMENSION num_cols = cinfo->output_width;
int ci;
while (--num_rows >= 0) {
for (ci = 0; ci < num_components; ci++) {
inptr = input_buf[ci][input_row];
outptr = output_buf[0] + ci;
for (count = num_cols; count > 0; count--) {
*outptr = *inptr++; /* needn't bother with GETJSAMPLE() here */
outptr += num_components;
}
}
input_row++;
output_buf++;
}
}
/*
* Color conversion for grayscale: just copy the data.
* This also works for YCbCr -> grayscale conversion, in which
* we just copy the Y (luminance) component and ignore chrominance.
*/
METHODDEF(void)
grayscale_convert (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows)
{
jcopy_sample_rows(input_buf[0], (int) input_row, output_buf, 0,
num_rows, cinfo->output_width);
}
/*
* Convert grayscale to RGB: just duplicate the graylevel three times.
* This is provided to support applications that don't want to cope
* with grayscale as a separate case.
*/
METHODDEF(void)
gray_rgb_convert (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows)
{
register JSAMPROW inptr, outptr;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->output_width;
while (--num_rows >= 0) {
inptr = input_buf[0][input_row++];
outptr = *output_buf++;
for (col = 0; col < num_cols; col++) {
/* We can dispense with GETJSAMPLE() here */
outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
outptr += RGB_PIXELSIZE;
}
}
}
/*
* Adobe-style YCCK->CMYK conversion.
* We convert YCbCr to R=1-C, G=1-M, and B=1-Y using the same
* conversion as above, while passing K (black) unchanged.
* We assume build_ycc_rgb_table has been called.
*/
METHODDEF(void)
ycck_cmyk_convert (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION input_row,
JSAMPARRAY output_buf, int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
register int y, cb, cr;
register JSAMPROW outptr;
register JSAMPROW inptr0, inptr1, inptr2, inptr3;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->output_width;
/* copy these pointers into registers if possible */
register JSAMPLE * range_limit = cinfo->sample_range_limit;
register int * Crrtab = cconvert->Cr_r_tab;
register int * Cbbtab = cconvert->Cb_b_tab;
register INT32 * Crgtab = cconvert->Cr_g_tab;
register INT32 * Cbgtab = cconvert->Cb_g_tab;
SHIFT_TEMPS
while (--num_rows >= 0) {
inptr0 = input_buf[0][input_row];
inptr1 = input_buf[1][input_row];
inptr2 = input_buf[2][input_row];
inptr3 = input_buf[3][input_row];
input_row++;
outptr = *output_buf++;
for (col = 0; col < num_cols; col++) {
y = GETJSAMPLE(inptr0[col]);
cb = GETJSAMPLE(inptr1[col]);
cr = GETJSAMPLE(inptr2[col]);
/* Range-limiting is essential due to noise introduced by DCT losses. */
outptr[0] = range_limit[MAXJSAMPLE - (y + Crrtab[cr])]; /* red */
outptr[1] = range_limit[MAXJSAMPLE - (y + /* green */
((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
SCALEBITS)))];
outptr[2] = range_limit[MAXJSAMPLE - (y + Cbbtab[cb])]; /* blue */
/* K passes through unchanged */
outptr[3] = inptr3[col]; /* don't need GETJSAMPLE here */
outptr += 4;
}
}
}
/*
* Empty method for start_pass.
*/
METHODDEF(void)
start_pass_dcolor (j_decompress_ptr cinfo)
{
/* no work needed */
}
/*
* Module initialization routine for output colorspace conversion.
*/
GLOBAL(void)
jinit_color_deconverter (j_decompress_ptr cinfo)
{
my_cconvert_ptr cconvert;
int ci;
cconvert = (my_cconvert_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_color_deconverter));
cinfo->cconvert = (struct jpeg_color_deconverter *) cconvert;
cconvert->pub.start_pass = start_pass_dcolor;
/* Make sure num_components agrees with jpeg_color_space */
switch (cinfo->jpeg_color_space) {
case JCS_GRAYSCALE:
if (cinfo->num_components != 1)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
break;
case JCS_RGB:
case JCS_YCbCr:
if (cinfo->num_components != 3)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
break;
case JCS_CMYK:
case JCS_YCCK:
if (cinfo->num_components != 4)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
break;
default: /* JCS_UNKNOWN can be anything */
if (cinfo->num_components < 1)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
break;
}
/* Set out_color_components and conversion method based on requested space.
* Also clear the component_needed flags for any unused components,
* so that earlier pipeline stages can avoid useless computation.
*/
switch (cinfo->out_color_space) {
case JCS_GRAYSCALE:
cinfo->out_color_components = 1;
if (cinfo->jpeg_color_space == JCS_GRAYSCALE ||
cinfo->jpeg_color_space == JCS_YCbCr) {
cconvert->pub.color_convert = grayscale_convert;
/* For color->grayscale conversion, only the Y (0) component is needed */
for (ci = 1; ci < cinfo->num_components; ci++)
cinfo->comp_info[ci].component_needed = FALSE;
} else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
case JCS_RGB:
cinfo->out_color_components = RGB_PIXELSIZE;
if (cinfo->jpeg_color_space == JCS_YCbCr) {
cconvert->pub.color_convert = ycc_rgb_convert;
build_ycc_rgb_table(cinfo);
} else if (cinfo->jpeg_color_space == JCS_GRAYSCALE) {
cconvert->pub.color_convert = gray_rgb_convert;
} else if (cinfo->jpeg_color_space == JCS_RGB && RGB_PIXELSIZE == 3) {
cconvert->pub.color_convert = null_convert;
} else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
case JCS_CMYK:
cinfo->out_color_components = 4;
if (cinfo->jpeg_color_space == JCS_YCCK) {
cconvert->pub.color_convert = ycck_cmyk_convert;
build_ycc_rgb_table(cinfo);
} else if (cinfo->jpeg_color_space == JCS_CMYK) {
cconvert->pub.color_convert = null_convert;
} else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
default:
/* Permit null conversion to same output space */
if (cinfo->out_color_space == cinfo->jpeg_color_space) {
cinfo->out_color_components = cinfo->num_components;
cconvert->pub.color_convert = null_convert;
} else /* unsupported non-null conversion */
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
}
if (cinfo->quantize_colors)
cinfo->output_components = 1; /* single colormapped output component */
else
cinfo->output_components = cinfo->out_color_components;
}
--- NEW FILE: jdmarker.c ---
/*
* jdmarker.c
*
* Copyright (C) 1991-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to decode JPEG datastream markers.
* Most of the complexity arises from our desire to support input
* suspension: if not all of the data for a marker is available,
* we must exit back to the application. On resumption, we reprocess
* the marker.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
[...1321 lines suppressed...]
#endif /* SAVE_MARKERS_SUPPORTED */
/*
* Install a special processing method for COM or APPn markers.
*/
GLOBAL(void)
jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
jpeg_marker_parser_method routine)
{
my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
if (marker_code == (int) M_COM)
marker->process_COM = routine;
else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
marker->process_APPn[marker_code - (int) M_APP0] = routine;
else
ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
}
--- NEW FILE: jdct.h ---
/*
* jdct.h
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This include file contains common declarations for the forward and
* inverse DCT modules. These declarations are private to the DCT managers
* (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
* The individual DCT algorithms are kept in separate files to ease
* machine-dependent tuning (e.g., assembly coding).
*/
/*
* A forward DCT routine is given a pointer to a work area of type DCTELEM[];
* the DCT is to be performed in-place in that buffer. Type DCTELEM is int
* for 8-bit samples, INT32 for 12-bit samples. (NOTE: Floating-point DCT
* implementations use an array of type FAST_FLOAT, instead.)
* The DCT inputs are expected to be signed (range +-CENTERJSAMPLE).
* The DCT outputs are returned scaled up by a factor of 8; they therefore
* have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
* convention improves accuracy in integer implementations and saves some
* work in floating-point ones.
* Quantization of the output coefficients is done by jcdctmgr.c.
*/
#if BITS_IN_JSAMPLE == 8
typedef int DCTELEM; /* 16 or 32 bits is fine */
#else
typedef INT32 DCTELEM; /* must have 32 bits */
#endif
typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data));
typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data));
/*
* An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
* to an output sample array. The routine must dequantize the input data as
* well as perform the IDCT; for dequantization, it uses the multiplier table
* pointed to by compptr->dct_table. The output data is to be placed into the
* sample array starting at a specified column. (Any row offset needed will
* be applied to the array pointer before it is passed to the IDCT code.)
* Note that the number of samples emitted by the IDCT routine is
* DCT_scaled_size * DCT_scaled_size.
*/
/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
/*
* Each IDCT routine has its own ideas about the best dct_table element type.
*/
typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
#if BITS_IN_JSAMPLE == 8
typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
#else
typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
#endif
typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
/*
* Each IDCT routine is responsible for range-limiting its results and
* converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
* be quite far out of range if the input data is corrupt, so a bulletproof
* range-limiting step is required. We use a mask-and-table-lookup method
* to do the combined operations quickly. See the comments with
* prepare_range_limit_table (in jdmaster.c) for more info.
*/
#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit + CENTERJSAMPLE)
#define RANGE_MASK (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */
/* Short forms of external names for systems with brain-damaged linkers. */
#ifdef NEED_SHORT_EXTERNAL_NAMES
#define jpeg_fdct_islow jFDislow
#define jpeg_fdct_ifast jFDifast
#define jpeg_fdct_float jFDfloat
#define jpeg_idct_islow jRDislow
#define jpeg_idct_ifast jRDifast
#define jpeg_idct_float jRDfloat
#define jpeg_idct_4x4 jRD4x4
#define jpeg_idct_2x2 jRD2x2
#define jpeg_idct_1x1 jRD1x1
#endif /* NEED_SHORT_EXTERNAL_NAMES */
/* Extern declarations for the forward and inverse DCT routines. */
EXTERN(void) jpeg_fdct_islow JPP((DCTELEM * data));
EXTERN(void) jpeg_fdct_ifast JPP((DCTELEM * data));
EXTERN(void) jpeg_fdct_float JPP((FAST_FLOAT * data));
EXTERN(void) jpeg_idct_islow
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_ifast
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_float
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_4x4
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_2x2
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
EXTERN(void) jpeg_idct_1x1
JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
/*
* Macros for handling fixed-point arithmetic; these are used by many
* but not all of the DCT/IDCT modules.
*
* All values are expected to be of type INT32.
* Fractional constants are scaled left by CONST_BITS bits.
* CONST_BITS is defined within each module using these macros,
* and may differ from one module to the next.
*/
#define ONE ((INT32) 1)
#define CONST_SCALE (ONE << CONST_BITS)
/* Convert a positive real constant to an integer scaled by CONST_SCALE.
* Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
* thus causing a lot of useless floating-point operations at run time.
*/
#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
/* Descale and correctly round an INT32 value that's scaled by N bits.
* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
* the fudge factor is correct for either sign of X.
*/
#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
* This macro is used only when the two inputs will actually be no more than
* 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
* full 32x32 multiply. This provides a useful speedup on many machines.
* Unfortunately there is no way to specify a 16x16->32 multiply portably
* in C, but some C compilers will do the right thing if you provide the
* correct combination of casts.
*/
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT16) (const)))
#endif
#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT32) (const)))
#endif
#ifndef MULTIPLY16C16 /* default definition */
#define MULTIPLY16C16(var,const) ((var) * (const))
#endif
/* Same except both inputs are variables. */
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
#define MULTIPLY16V16(var1,var2) (((INT16) (var1)) * ((INT16) (var2)))
#endif
#ifndef MULTIPLY16V16 /* default definition */
#define MULTIPLY16V16(var1,var2) ((var1) * (var2))
#endif
--- NEW FILE: jdpostct.c ---
/*
* jdpostct.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains the decompression postprocessing controller.
* This controller manages the upsampling, color conversion, and color
* quantization/reduction steps; specifically, it controls the buffering
* between upsample/color conversion and color quantization/reduction.
*
* If no color quantization/reduction is required, then this module has no
* work to do, and it just hands off to the upsample/color conversion code.
* An integrated upsample/convert/quantize process would replace this module
* entirely.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Private buffer controller object */
typedef struct {
struct jpeg_d_post_controller pub; /* public fields */
/* Color quantization source buffer: this holds output data from
* the upsample/color conversion step to be passed to the quantizer.
* For two-pass color quantization, we need a full-image buffer;
* for one-pass operation, a strip buffer is sufficient.
*/
jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */
JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */
JDIMENSION strip_height; /* buffer size in rows */
/* for two-pass mode only: */
JDIMENSION starting_row; /* row # of first row in current strip */
JDIMENSION next_row; /* index of next row to fill/empty in strip */
} my_post_controller;
typedef my_post_controller * my_post_ptr;
/* Forward declarations */
METHODDEF(void) post_process_1pass
JPP((j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail));
#ifdef QUANT_2PASS_SUPPORTED
METHODDEF(void) post_process_prepass
JPP((j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail));
METHODDEF(void) post_process_2pass
JPP((j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail));
#endif
/*
* Initialize for a processing pass.
*/
METHODDEF(void)
start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
{
my_post_ptr post = (my_post_ptr) cinfo->post;
switch (pass_mode) {
case JBUF_PASS_THRU:
if (cinfo->quantize_colors) {
/* Single-pass processing with color quantization. */
post->pub.post_process_data = post_process_1pass;
/* We could be doing buffered-image output before starting a 2-pass
* color quantization; in that case, jinit_d_post_controller did not
* allocate a strip buffer. Use the virtual-array buffer as workspace.
*/
if (post->buffer == NULL) {
post->buffer = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, post->whole_image,
(JDIMENSION) 0, post->strip_height, TRUE);
}
} else {
/* For single-pass processing without color quantization,
* I have no work to do; just call the upsampler directly.
*/
post->pub.post_process_data = cinfo->upsample->upsample;
}
break;
#ifdef QUANT_2PASS_SUPPORTED
case JBUF_SAVE_AND_PASS:
/* First pass of 2-pass quantization */
if (post->whole_image == NULL)
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
post->pub.post_process_data = post_process_prepass;
break;
case JBUF_CRANK_DEST:
/* Second pass of 2-pass quantization */
if (post->whole_image == NULL)
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
post->pub.post_process_data = post_process_2pass;
break;
#endif /* QUANT_2PASS_SUPPORTED */
default:
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
break;
}
post->starting_row = post->next_row = 0;
}
/*
* Process some data in the one-pass (strip buffer) case.
* This is used for color precision reduction as well as one-pass quantization.
*/
METHODDEF(void)
post_process_1pass (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
my_post_ptr post = (my_post_ptr) cinfo->post;
JDIMENSION num_rows, max_rows;
/* Fill the buffer, but not more than what we can dump out in one go. */
/* Note we rely on the upsampler to detect bottom of image. */
max_rows = out_rows_avail - *out_row_ctr;
if (max_rows > post->strip_height)
max_rows = post->strip_height;
num_rows = 0;
(*cinfo->upsample->upsample) (cinfo,
input_buf, in_row_group_ctr, in_row_groups_avail,
post->buffer, &num_rows, max_rows);
/* Quantize and emit data. */
(*cinfo->cquantize->color_quantize) (cinfo,
post->buffer, output_buf + *out_row_ctr, (int) num_rows);
*out_row_ctr += num_rows;
}
#ifdef QUANT_2PASS_SUPPORTED
/*
* Process some data in the first pass of 2-pass quantization.
*/
METHODDEF(void)
post_process_prepass (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
my_post_ptr post = (my_post_ptr) cinfo->post;
JDIMENSION old_next_row, num_rows;
/* Reposition virtual buffer if at start of strip. */
if (post->next_row == 0) {
post->buffer = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, post->whole_image,
post->starting_row, post->strip_height, TRUE);
}
/* Upsample some data (up to a strip height's worth). */
old_next_row = post->next_row;
(*cinfo->upsample->upsample) (cinfo,
input_buf, in_row_group_ctr, in_row_groups_avail,
post->buffer, &post->next_row, post->strip_height);
/* Allow quantizer to scan new data. No data is emitted, */
/* but we advance out_row_ctr so outer loop can tell when we're done. */
if (post->next_row > old_next_row) {
num_rows = post->next_row - old_next_row;
(*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
(JSAMPARRAY) NULL, (int) num_rows);
*out_row_ctr += num_rows;
}
/* Advance if we filled the strip. */
if (post->next_row >= post->strip_height) {
post->starting_row += post->strip_height;
post->next_row = 0;
}
}
/*
* Process some data in the second pass of 2-pass quantization.
*/
METHODDEF(void)
post_process_2pass (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
my_post_ptr post = (my_post_ptr) cinfo->post;
JDIMENSION num_rows, max_rows;
/* Reposition virtual buffer if at start of strip. */
if (post->next_row == 0) {
post->buffer = (*cinfo->mem->access_virt_sarray)
((j_common_ptr) cinfo, post->whole_image,
post->starting_row, post->strip_height, FALSE);
}
/* Determine number of rows to emit. */
num_rows = post->strip_height - post->next_row; /* available in strip */
max_rows = out_rows_avail - *out_row_ctr; /* available in output area */
if (num_rows > max_rows)
num_rows = max_rows;
/* We have to check bottom of image here, can't depend on upsampler. */
max_rows = cinfo->output_height - post->starting_row;
if (num_rows > max_rows)
num_rows = max_rows;
/* Quantize and emit data. */
(*cinfo->cquantize->color_quantize) (cinfo,
post->buffer + post->next_row, output_buf + *out_row_ctr,
(int) num_rows);
*out_row_ctr += num_rows;
/* Advance if we filled the strip. */
post->next_row += num_rows;
if (post->next_row >= post->strip_height) {
post->starting_row += post->strip_height;
post->next_row = 0;
}
}
#endif /* QUANT_2PASS_SUPPORTED */
/*
* Initialize postprocessing controller.
*/
GLOBAL(void)
jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
{
my_post_ptr post;
post = (my_post_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_post_controller));
cinfo->post = (struct jpeg_d_post_controller *) post;
post->pub.start_pass = start_pass_dpost;
post->whole_image = NULL; /* flag for no virtual arrays */
post->buffer = NULL; /* flag for no strip buffer */
/* Create the quantization buffer, if needed */
if (cinfo->quantize_colors) {
/* The buffer strip height is max_v_samp_factor, which is typically
* an efficient number of rows for upsampling to return.
* (In the presence of output rescaling, we might want to be smarter?)
*/
post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
if (need_full_buffer) {
/* Two-pass color quantization: need full-image storage. */
/* We round up the number of rows to a multiple of the strip height. */
#ifdef QUANT_2PASS_SUPPORTED
post->whole_image = (*cinfo->mem->request_virt_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
cinfo->output_width * cinfo->out_color_components,
(JDIMENSION) jround_up((long) cinfo->output_height,
(long) post->strip_height),
post->strip_height);
#else
ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
#endif /* QUANT_2PASS_SUPPORTED */
} else {
/* One-pass color quantization: just make a strip buffer. */
post->buffer = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->output_width * cinfo->out_color_components,
post->strip_height);
}
}
}
--- NEW FILE: jquant2.c ---
/*
* jquant2.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains 2-pass color quantization (color mapping) routines.
* These routines provide selection of a custom color map for an image,
* followed by mapping of the image to that color map, with optional
* Floyd-Steinberg dithering.
* It is also possible to use just the second pass to map to an arbitrary
* externally-given color map.
*
* Note: ordered dithering is not supported, since there isn't any fast
* way to compute intercolor distances; it's unclear that ordered dither's
* fundamental assumptions even hold with an irregularly spaced color map.
*/
[...1271 lines suppressed...]
/* Only F-S dithering or no dithering is supported. */
/* If user asks for ordered dither, give him F-S. */
if (cinfo->dither_mode != JDITHER_NONE)
cinfo->dither_mode = JDITHER_FS;
/* Allocate Floyd-Steinberg workspace if necessary.
* This isn't really needed until pass 2, but again it is FAR storage.
* Although we will cope with a later change in dither_mode,
* we do not promise to honor max_memory_to_use if dither_mode changes.
*/
if (cinfo->dither_mode == JDITHER_FS) {
cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(size_t) ((cinfo->output_width + 2) * (3 * SIZEOF(FSERROR))));
/* Might as well create the error-limiting table too. */
init_error_limit(cinfo);
}
}
#endif /* QUANT_2PASS_SUPPORTED */
--- NEW FILE: jquant1.c ---
/*
* jquant1.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains 1-pass color quantization (color mapping) routines.
* These routines provide mapping to a fixed color map using equally spaced
* color values. Optional Floyd-Steinberg or ordered dithering is available.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#ifdef QUANT_1PASS_SUPPORTED
/*
* The main purpose of 1-pass quantization is to provide a fast, if not very
* high quality, colormapped output capability. A 2-pass quantizer usually
* gives better visual quality; however, for quantized grayscale output this
* quantizer is perfectly adequate. Dithering is highly recommended with this
* quantizer, though you can turn it off if you really want to.
*
* In 1-pass quantization the colormap must be chosen in advance of seeing the
* image. We use a map consisting of all combinations of Ncolors[i] color
* values for the i'th component. The Ncolors[] values are chosen so that
* their product, the total number of colors, is no more than that requested.
* (In most cases, the product will be somewhat less.)
*
* Since the colormap is orthogonal, the representative value for each color
* component can be determined without considering the other components;
* then these indexes can be combined into a colormap index by a standard
* N-dimensional-array-subscript calculation. Most of the arithmetic involved
* can be precalculated and stored in the lookup table colorindex[].
* colorindex[i][j] maps pixel value j in component i to the nearest
* representative value (grid plane) for that component; this index is
* multiplied by the array stride for component i, so that the
* index of the colormap entry closest to a given pixel value is just
* sum( colorindex[component-number][pixel-component-value] )
* Aside from being fast, this scheme allows for variable spacing between
* representative values with no additional lookup cost.
*
* If gamma correction has been applied in color conversion, it might be wise
* to adjust the color grid spacing so that the representative colors are
* equidistant in linear space. At this writing, gamma correction is not
* implemented by jdcolor, so nothing is done here.
*/
/* Declarations for ordered dithering.
*
* We use a standard 16x16 ordered dither array. The basic concept of ordered
* dithering is described in many references, for instance Dale Schumacher's
* chapter II.2 of Graphics Gems II (James Arvo, ed. Academic Press, 1991).
* In place of Schumacher's comparisons against a "threshold" value, we add a
* "dither" value to the input pixel and then round the result to the nearest
* output value. The dither value is equivalent to (0.5 - threshold) times
* the distance between output values. For ordered dithering, we assume that
* the output colors are equally spaced; if not, results will probably be
* worse, since the dither may be too much or too little at a given point.
*
* The normal calculation would be to form pixel value + dither, range-limit
* this to 0..MAXJSAMPLE, and then index into the colorindex table as usual.
* We can skip the separate range-limiting step by extending the colorindex
* table in both directions.
*/
#define ODITHER_SIZE 16 /* dimension of dither matrix */
/* NB: if ODITHER_SIZE is not a power of 2, ODITHER_MASK uses will break */
#define ODITHER_CELLS (ODITHER_SIZE*ODITHER_SIZE) /* # cells in matrix */
#define ODITHER_MASK (ODITHER_SIZE-1) /* mask for wrapping around counters */
typedef int ODITHER_MATRIX[ODITHER_SIZE][ODITHER_SIZE];
typedef int (*ODITHER_MATRIX_PTR)[ODITHER_SIZE];
static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = {
/* Bayer's order-4 dither array. Generated by the code given in
* Stephen Hawley's article "Ordered Dithering" in Graphics Gems I.
* The values in this array must range from 0 to ODITHER_CELLS-1.
*/
{ 0,192, 48,240, 12,204, 60,252, 3,195, 51,243, 15,207, 63,255 },
{ 128, 64,176,112,140, 76,188,124,131, 67,179,115,143, 79,191,127 },
{ 32,224, 16,208, 44,236, 28,220, 35,227, 19,211, 47,239, 31,223 },
{ 160, 96,144, 80,172,108,156, 92,163, 99,147, 83,175,111,159, 95 },
{ 8,200, 56,248, 4,196, 52,244, 11,203, 59,251, 7,199, 55,247 },
{ 136, 72,184,120,132, 68,180,116,139, 75,187,123,135, 71,183,119 },
{ 40,232, 24,216, 36,228, 20,212, 43,235, 27,219, 39,231, 23,215 },
{ 168,104,152, 88,164,100,148, 84,171,107,155, 91,167,103,151, 87 },
{ 2,194, 50,242, 14,206, 62,254, 1,193, 49,241, 13,205, 61,253 },
{ 130, 66,178,114,142, 78,190,126,129, 65,177,113,141, 77,189,125 },
{ 34,226, 18,210, 46,238, 30,222, 33,225, 17,209, 45,237, 29,221 },
{ 162, 98,146, 82,174,110,158, 94,161, 97,145, 81,173,109,157, 93 },
{ 10,202, 58,250, 6,198, 54,246, 9,201, 57,249, 5,197, 53,245 },
{ 138, 74,186,122,134, 70,182,118,137, 73,185,121,133, 69,181,117 },
{ 42,234, 26,218, 38,230, 22,214, 41,233, 25,217, 37,229, 21,213 },
{ 170,106,154, 90,166,102,150, 86,169,105,153, 89,165,101,149, 85 }
};
/* Declarations for Floyd-Steinberg dithering.
*
* Errors are accumulated into the array fserrors[], at a resolution of
* 1/16th of a pixel count. The error at a given pixel is propagated
* to its not-yet-processed neighbors using the standard F-S fractions,
* ... (here) 7/16
* 3/16 5/16 1/16
* We work left-to-right on even rows, right-to-left on odd rows.
*
* We can get away with a single array (holding one row's worth of errors)
* by using it to store the current row's errors at pixel columns not yet
* processed, but the next row's errors at columns already processed. We
* need only a few extra variables to hold the errors immediately around the
* current column. (If we are lucky, those variables are in registers, but
* even if not, they're probably cheaper to access than array elements are.)
*
* The fserrors[] array is indexed [component#][position].
* We provide (#columns + 2) entries per component; the extra entry at each
* end saves us from special-casing the first and last pixels.
*
* Note: on a wide image, we might not have enough room in a PC's near data
* segment to hold the error array; so it is allocated with alloc_large.
*/
#if BITS_IN_JSAMPLE == 8
typedef INT16 FSERROR; /* 16 bits should be enough */
typedef int LOCFSERROR; /* use 'int' for calculation temps */
#else
typedef INT32 FSERROR; /* may need more than 16 bits */
typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */
#endif
typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */
/* Private subobject */
#define MAX_Q_COMPS 4 /* max components I can handle */
typedef struct {
struct jpeg_color_quantizer pub; /* public fields */
/* Initially allocated colormap is saved here */
JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */
int sv_actual; /* number of entries in use */
JSAMPARRAY colorindex; /* Precomputed mapping for speed */
/* colorindex[i][j] = index of color closest to pixel value j in component i,
* premultiplied as described above. Since colormap indexes must fit into
* JSAMPLEs, the entries of this array will too.
*/
boolean is_padded; /* is the colorindex padded for odither? */
int Ncolors[MAX_Q_COMPS]; /* # of values alloced to each component */
/* Variables for ordered dithering */
int row_index; /* cur row's vertical index in dither matrix */
ODITHER_MATRIX_PTR odither[MAX_Q_COMPS]; /* one dither array per component */
/* Variables for Floyd-Steinberg dithering */
FSERRPTR fserrors[MAX_Q_COMPS]; /* accumulated errors */
boolean on_odd_row; /* flag to remember which row we are on */
} my_cquantizer;
typedef my_cquantizer * my_cquantize_ptr;
/*
* Policy-making subroutines for create_colormap and create_colorindex.
* These routines determine the colormap to be used. The rest of the module
* only assumes that the colormap is orthogonal.
*
* * select_ncolors decides how to divvy up the available colors
* among the components.
* * output_value defines the set of representative values for a component.
* * largest_input_value defines the mapping from input values to
* representative values for a component.
* Note that the latter two routines may impose different policies for
* different components, though this is not currently done.
*/
LOCAL(int)
select_ncolors (j_decompress_ptr cinfo, int Ncolors[])
/* Determine allocation of desired colors to components, */
/* and fill in Ncolors[] array to indicate choice. */
/* Return value is total number of colors (product of Ncolors[] values). */
{
int nc = cinfo->out_color_components; /* number of color components */
int max_colors = cinfo->desired_number_of_colors;
int total_colors, iroot, i, j;
boolean changed;
long temp;
static const int RGB_order[3] = { RGB_GREEN, RGB_RED, RGB_BLUE };
/* We can allocate at least the nc'th root of max_colors per component. */
/* Compute floor(nc'th root of max_colors). */
iroot = 1;
do {
iroot++;
temp = iroot; /* set temp = iroot ** nc */
for (i = 1; i < nc; i++)
temp *= iroot;
} while (temp <= (long) max_colors); /* repeat till iroot exceeds root */
iroot--; /* now iroot = floor(root) */
/* Must have at least 2 color values per component */
if (iroot < 2)
ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, (int) temp);
/* Initialize to iroot color values for each component */
total_colors = 1;
for (i = 0; i < nc; i++) {
Ncolors[i] = iroot;
total_colors *= iroot;
}
/* We may be able to increment the count for one or more components without
* exceeding max_colors, though we know not all can be incremented.
* Sometimes, the first component can be incremented more than once!
* (Example: for 16 colors, we start at 2*2*2, go to 3*2*2, then 4*2*2.)
* In RGB colorspace, try to increment G first, then R, then B.
*/
do {
changed = FALSE;
for (i = 0; i < nc; i++) {
j = (cinfo->out_color_space == JCS_RGB ? RGB_order[i] : i);
/* calculate new total_colors if Ncolors[j] is incremented */
temp = total_colors / Ncolors[j];
temp *= Ncolors[j]+1; /* done in long arith to avoid oflo */
if (temp > (long) max_colors)
break; /* won't fit, done with this pass */
Ncolors[j]++; /* OK, apply the increment */
total_colors = (int) temp;
changed = TRUE;
}
} while (changed);
return total_colors;
}
LOCAL(int)
output_value (j_decompress_ptr cinfo, int ci, int j, int maxj)
/* Return j'th output value, where j will range from 0 to maxj */
/* The output values must fall in 0..MAXJSAMPLE in increasing order */
{
/* We always provide values 0 and MAXJSAMPLE for each component;
* any additional values are equally spaced between these limits.
* (Forcing the upper and lower values to the limits ensures that
* dithering can't produce a color outside the selected gamut.)
*/
return (int) (((INT32) j * MAXJSAMPLE + maxj/2) / maxj);
}
LOCAL(int)
largest_input_value (j_decompress_ptr cinfo, int ci, int j, int maxj)
/* Return largest input value that should map to j'th output value */
/* Must have largest(j=0) >= 0, and largest(j=maxj) >= MAXJSAMPLE */
{
/* Breakpoints are halfway between values returned by output_value */
return (int) (((INT32) (2*j + 1) * MAXJSAMPLE + maxj) / (2*maxj));
}
/*
* Create the colormap.
*/
LOCAL(void)
create_colormap (j_decompress_ptr cinfo)
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
JSAMPARRAY colormap; /* Created colormap */
int total_colors; /* Number of distinct output colors */
int i,j,k, nci, blksize, blkdist, ptr, val;
/* Select number of colors for each component */
total_colors = select_ncolors(cinfo, cquantize->Ncolors);
/* Report selected color counts */
if (cinfo->out_color_components == 3)
TRACEMS4(cinfo, 1, JTRC_QUANT_3_NCOLORS,
total_colors, cquantize->Ncolors[0],
cquantize->Ncolors[1], cquantize->Ncolors[2]);
else
TRACEMS1(cinfo, 1, JTRC_QUANT_NCOLORS, total_colors);
/* Allocate and fill in the colormap. */
/* The colors are ordered in the map in standard row-major order, */
/* i.e. rightmost (highest-indexed) color changes most rapidly. */
colormap = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(JDIMENSION) total_colors, (JDIMENSION) cinfo->out_color_components);
/* blksize is number of adjacent repeated entries for a component */
/* blkdist is distance between groups of identical entries for a component */
blkdist = total_colors;
for (i = 0; i < cinfo->out_color_components; i++) {
/* fill in colormap entries for i'th color component */
nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
blksize = blkdist / nci;
for (j = 0; j < nci; j++) {
/* Compute j'th output value (out of nci) for component */
val = output_value(cinfo, i, j, nci-1);
/* Fill in all colormap entries that have this value of this component */
for (ptr = j * blksize; ptr < total_colors; ptr += blkdist) {
/* fill in blksize entries beginning at ptr */
for (k = 0; k < blksize; k++)
colormap[i][ptr+k] = (JSAMPLE) val;
}
}
blkdist = blksize; /* blksize of this color is blkdist of next */
}
/* Save the colormap in private storage,
* where it will survive color quantization mode changes.
*/
cquantize->sv_colormap = colormap;
cquantize->sv_actual = total_colors;
}
/*
* Create the color index table.
*/
LOCAL(void)
create_colorindex (j_decompress_ptr cinfo)
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
JSAMPROW indexptr;
int i,j,k, nci, blksize, val, pad;
/* For ordered dither, we pad the color index tables by MAXJSAMPLE in
* each direction (input index values can be -MAXJSAMPLE .. 2*MAXJSAMPLE).
* This is not necessary in the other dithering modes. However, we
* flag whether it was done in case user changes dithering mode.
*/
if (cinfo->dither_mode == JDITHER_ORDERED) {
pad = MAXJSAMPLE*2;
cquantize->is_padded = TRUE;
} else {
pad = 0;
cquantize->is_padded = FALSE;
}
cquantize->colorindex = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(JDIMENSION) (MAXJSAMPLE+1 + pad),
(JDIMENSION) cinfo->out_color_components);
/* blksize is number of adjacent repeated entries for a component */
blksize = cquantize->sv_actual;
for (i = 0; i < cinfo->out_color_components; i++) {
/* fill in colorindex entries for i'th color component */
nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
blksize = blksize / nci;
/* adjust colorindex pointers to provide padding at negative indexes. */
if (pad)
cquantize->colorindex[i] += MAXJSAMPLE;
/* in loop, val = index of current output value, */
/* and k = largest j that maps to current val */
indexptr = cquantize->colorindex[i];
val = 0;
k = largest_input_value(cinfo, i, 0, nci-1);
for (j = 0; j <= MAXJSAMPLE; j++) {
while (j > k) /* advance val if past boundary */
k = largest_input_value(cinfo, i, ++val, nci-1);
/* premultiply so that no multiplication needed in main processing */
indexptr[j] = (JSAMPLE) (val * blksize);
}
/* Pad at both ends if necessary */
if (pad)
for (j = 1; j <= MAXJSAMPLE; j++) {
indexptr[-j] = indexptr[0];
indexptr[MAXJSAMPLE+j] = indexptr[MAXJSAMPLE];
}
}
}
/*
* Create an ordered-dither array for a component having ncolors
* distinct output values.
*/
LOCAL(ODITHER_MATRIX_PTR)
make_odither_array (j_decompress_ptr cinfo, int ncolors)
{
ODITHER_MATRIX_PTR odither;
int j,k;
INT32 num,den;
odither = (ODITHER_MATRIX_PTR)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(ODITHER_MATRIX));
/* The inter-value distance for this color is MAXJSAMPLE/(ncolors-1).
* Hence the dither value for the matrix cell with fill order f
* (f=0..N-1) should be (N-1-2*f)/(2*N) * MAXJSAMPLE/(ncolors-1).
* On 16-bit-int machine, be careful to avoid overflow.
*/
den = 2 * ODITHER_CELLS * ((INT32) (ncolors - 1));
for (j = 0; j < ODITHER_SIZE; j++) {
for (k = 0; k < ODITHER_SIZE; k++) {
num = ((INT32) (ODITHER_CELLS-1 - 2*((int)base_dither_matrix[j][k])))
* MAXJSAMPLE;
/* Ensure round towards zero despite C's lack of consistency
* about rounding negative values in integer division...
*/
odither[j][k] = (int) (num<0 ? -((-num)/den) : num/den);
}
}
return odither;
}
/*
* Create the ordered-dither tables.
* Components having the same number of representative colors may
* share a dither table.
*/
LOCAL(void)
create_odither_tables (j_decompress_ptr cinfo)
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
ODITHER_MATRIX_PTR odither;
int i, j, nci;
for (i = 0; i < cinfo->out_color_components; i++) {
nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
odither = NULL; /* search for matching prior component */
for (j = 0; j < i; j++) {
if (nci == cquantize->Ncolors[j]) {
odither = cquantize->odither[j];
break;
}
}
if (odither == NULL) /* need a new table? */
odither = make_odither_array(cinfo, nci);
cquantize->odither[i] = odither;
}
}
/*
* Map some rows of pixels to the output colormapped representation.
*/
METHODDEF(void)
color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPARRAY output_buf, int num_rows)
/* General case, no dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
JSAMPARRAY colorindex = cquantize->colorindex;
register int pixcode, ci;
register JSAMPROW ptrin, ptrout;
int row;
JDIMENSION col;
JDIMENSION width = cinfo->output_width;
register int nc = cinfo->out_color_components;
for (row = 0; row < num_rows; row++) {
ptrin = input_buf[row];
ptrout = output_buf[row];
for (col = width; col > 0; col--) {
pixcode = 0;
for (ci = 0; ci < nc; ci++) {
pixcode += GETJSAMPLE(colorindex[ci][GETJSAMPLE(*ptrin++)]);
}
*ptrout++ = (JSAMPLE) pixcode;
}
}
}
METHODDEF(void)
color_quantize3 (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPARRAY output_buf, int num_rows)
/* Fast path for out_color_components==3, no dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
register int pixcode;
register JSAMPROW ptrin, ptrout;
JSAMPROW colorindex0 = cquantize->colorindex[0];
JSAMPROW colorindex1 = cquantize->colorindex[1];
JSAMPROW colorindex2 = cquantize->colorindex[2];
int row;
JDIMENSION col;
JDIMENSION width = cinfo->output_width;
for (row = 0; row < num_rows; row++) {
ptrin = input_buf[row];
ptrout = output_buf[row];
for (col = width; col > 0; col--) {
pixcode = GETJSAMPLE(colorindex0[GETJSAMPLE(*ptrin++)]);
pixcode += GETJSAMPLE(colorindex1[GETJSAMPLE(*ptrin++)]);
pixcode += GETJSAMPLE(colorindex2[GETJSAMPLE(*ptrin++)]);
*ptrout++ = (JSAMPLE) pixcode;
}
}
}
METHODDEF(void)
quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPARRAY output_buf, int num_rows)
/* General case, with ordered dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
register JSAMPROW input_ptr;
register JSAMPROW output_ptr;
JSAMPROW colorindex_ci;
int * dither; /* points to active row of dither matrix */
int row_index, col_index; /* current indexes into dither matrix */
int nc = cinfo->out_color_components;
int ci;
int row;
JDIMENSION col;
JDIMENSION width = cinfo->output_width;
for (row = 0; row < num_rows; row++) {
/* Initialize output values to 0 so can process components separately */
jzero_far((void FAR *) output_buf[row],
(size_t) (width * SIZEOF(JSAMPLE)));
row_index = cquantize->row_index;
for (ci = 0; ci < nc; ci++) {
input_ptr = input_buf[row] + ci;
output_ptr = output_buf[row];
colorindex_ci = cquantize->colorindex[ci];
dither = cquantize->odither[ci][row_index];
col_index = 0;
for (col = width; col > 0; col--) {
/* Form pixel value + dither, range-limit to 0..MAXJSAMPLE,
* select output value, accumulate into output code for this pixel.
* Range-limiting need not be done explicitly, as we have extended
* the colorindex table to produce the right answers for out-of-range
* inputs. The maximum dither is +- MAXJSAMPLE; this sets the
* required amount of padding.
*/
*output_ptr += colorindex_ci[GETJSAMPLE(*input_ptr)+dither[col_index]];
input_ptr += nc;
output_ptr++;
col_index = (col_index + 1) & ODITHER_MASK;
}
}
/* Advance row index for next row */
row_index = (row_index + 1) & ODITHER_MASK;
cquantize->row_index = row_index;
}
}
METHODDEF(void)
quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPARRAY output_buf, int num_rows)
/* Fast path for out_color_components==3, with ordered dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
register int pixcode;
register JSAMPROW input_ptr;
register JSAMPROW output_ptr;
JSAMPROW colorindex0 = cquantize->colorindex[0];
JSAMPROW colorindex1 = cquantize->colorindex[1];
JSAMPROW colorindex2 = cquantize->colorindex[2];
int * dither0; /* points to active row of dither matrix */
int * dither1;
int * dither2;
int row_index, col_index; /* current indexes into dither matrix */
int row;
JDIMENSION col;
JDIMENSION width = cinfo->output_width;
for (row = 0; row < num_rows; row++) {
row_index = cquantize->row_index;
input_ptr = input_buf[row];
output_ptr = output_buf[row];
dither0 = cquantize->odither[0][row_index];
dither1 = cquantize->odither[1][row_index];
dither2 = cquantize->odither[2][row_index];
col_index = 0;
for (col = width; col > 0; col--) {
pixcode = GETJSAMPLE(colorindex0[GETJSAMPLE(*input_ptr++) +
dither0[col_index]]);
pixcode += GETJSAMPLE(colorindex1[GETJSAMPLE(*input_ptr++) +
dither1[col_index]]);
pixcode += GETJSAMPLE(colorindex2[GETJSAMPLE(*input_ptr++) +
dither2[col_index]]);
*output_ptr++ = (JSAMPLE) pixcode;
col_index = (col_index + 1) & ODITHER_MASK;
}
row_index = (row_index + 1) & ODITHER_MASK;
cquantize->row_index = row_index;
}
}
METHODDEF(void)
quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPARRAY output_buf, int num_rows)
/* General case, with Floyd-Steinberg dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
register LOCFSERROR cur; /* current error or pixel value */
LOCFSERROR belowerr; /* error for pixel below cur */
LOCFSERROR bpreverr; /* error for below/prev col */
LOCFSERROR bnexterr; /* error for below/next col */
LOCFSERROR delta;
register FSERRPTR errorptr; /* => fserrors[] at column before current */
register JSAMPROW input_ptr;
register JSAMPROW output_ptr;
JSAMPROW colorindex_ci;
JSAMPROW colormap_ci;
int pixcode;
int nc = cinfo->out_color_components;
int dir; /* 1 for left-to-right, -1 for right-to-left */
int dirnc; /* dir * nc */
int ci;
int row;
JDIMENSION col;
JDIMENSION width = cinfo->output_width;
JSAMPLE *range_limit = cinfo->sample_range_limit;
SHIFT_TEMPS
for (row = 0; row < num_rows; row++) {
/* Initialize output values to 0 so can process components separately */
jzero_far((void FAR *) output_buf[row],
(size_t) (width * SIZEOF(JSAMPLE)));
for (ci = 0; ci < nc; ci++) {
input_ptr = input_buf[row] + ci;
output_ptr = output_buf[row];
if (cquantize->on_odd_row) {
/* work right to left in this row */
input_ptr += (width-1) * nc; /* so point to rightmost pixel */
output_ptr += width-1;
dir = -1;
dirnc = -nc;
errorptr = cquantize->fserrors[ci] + (width+1); /* => entry after last column */
} else {
/* work left to right in this row */
dir = 1;
dirnc = nc;
errorptr = cquantize->fserrors[ci]; /* => entry before first column */
}
colorindex_ci = cquantize->colorindex[ci];
colormap_ci = cquantize->sv_colormap[ci];
/* Preset error values: no error propagated to first pixel from left */
cur = 0;
/* and no error propagated to row below yet */
belowerr = bpreverr = 0;
for (col = width; col > 0; col--) {
/* cur holds the error propagated from the previous pixel on the
* current line. Add the error propagated from the previous line
* to form the complete error correction term for this pixel, and
* round the error term (which is expressed * 16) to an integer.
* RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct
* for either sign of the error value.
* Note: errorptr points to *previous* column's array entry.
*/
cur = RIGHT_SHIFT(cur + errorptr[dir] + 8, 4);
/* Form pixel value + error, and range-limit to 0..MAXJSAMPLE.
* The maximum error is +- MAXJSAMPLE; this sets the required size
* of the range_limit array.
*/
cur += GETJSAMPLE(*input_ptr);
cur = GETJSAMPLE(range_limit[cur]);
/* Select output value, accumulate into output code for this pixel */
pixcode = GETJSAMPLE(colorindex_ci[cur]);
*output_ptr += (JSAMPLE) pixcode;
/* Compute actual representation error at this pixel */
/* Note: we can do this even though we don't have the final */
/* pixel code, because the colormap is orthogonal. */
cur -= GETJSAMPLE(colormap_ci[pixcode]);
/* Compute error fractions to be propagated to adjacent pixels.
* Add these into the running sums, and simultaneously shift the
* next-line error sums left by 1 column.
*/
bnexterr = cur;
delta = cur * 2;
cur += delta; /* form error * 3 */
errorptr[0] = (FSERROR) (bpreverr + cur);
cur += delta; /* form error * 5 */
bpreverr = belowerr + cur;
belowerr = bnexterr;
cur += delta; /* form error * 7 */
/* At this point cur contains the 7/16 error value to be propagated
* to the next pixel on the current line, and all the errors for the
* next line have been shifted over. We are therefore ready to move on.
*/
input_ptr += dirnc; /* advance input ptr to next column */
output_ptr += dir; /* advance output ptr to next column */
errorptr += dir; /* advance errorptr to current column */
}
/* Post-loop cleanup: we must unload the final error value into the
* final fserrors[] entry. Note we need not unload belowerr because
* it is for the dummy column before or after the actual array.
*/
errorptr[0] = (FSERROR) bpreverr; /* unload prev err into array */
}
cquantize->on_odd_row = (cquantize->on_odd_row ? FALSE : TRUE);
}
}
/*
* Allocate workspace for Floyd-Steinberg errors.
*/
LOCAL(void)
alloc_fs_workspace (j_decompress_ptr cinfo)
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
size_t arraysize;
int i;
arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR));
for (i = 0; i < cinfo->out_color_components; i++) {
cquantize->fserrors[i] = (FSERRPTR)
(*cinfo->mem->alloc_large)((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize);
}
}
/*
* Initialize for one-pass color quantization.
*/
METHODDEF(void)
start_pass_1_quant (j_decompress_ptr cinfo, boolean is_pre_scan)
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
size_t arraysize;
int i;
/* Install my colormap. */
cinfo->colormap = cquantize->sv_colormap;
cinfo->actual_number_of_colors = cquantize->sv_actual;
/* Initialize for desired dithering mode. */
switch (cinfo->dither_mode) {
case JDITHER_NONE:
if (cinfo->out_color_components == 3)
cquantize->pub.color_quantize = color_quantize3;
else
cquantize->pub.color_quantize = color_quantize;
break;
case JDITHER_ORDERED:
if (cinfo->out_color_components == 3)
cquantize->pub.color_quantize = quantize3_ord_dither;
else
cquantize->pub.color_quantize = quantize_ord_dither;
cquantize->row_index = 0; /* initialize state for ordered dither */
/* If user changed to ordered dither from another mode,
* we must recreate the color index table with padding.
* This will cost extra space, but probably isn't very likely.
*/
if (! cquantize->is_padded)
create_colorindex(cinfo);
/* Create ordered-dither tables if we didn't already. */
if (cquantize->odither[0] == NULL)
create_odither_tables(cinfo);
break;
case JDITHER_FS:
cquantize->pub.color_quantize = quantize_fs_dither;
cquantize->on_odd_row = FALSE; /* initialize state for F-S dither */
/* Allocate Floyd-Steinberg workspace if didn't already. */
if (cquantize->fserrors[0] == NULL)
alloc_fs_workspace(cinfo);
/* Initialize the propagated errors to zero. */
arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR));
for (i = 0; i < cinfo->out_color_components; i++)
jzero_far((void FAR *) cquantize->fserrors[i], arraysize);
break;
default:
ERREXIT(cinfo, JERR_NOT_COMPILED);
break;
}
}
/*
* Finish up at the end of the pass.
*/
METHODDEF(void)
finish_pass_1_quant (j_decompress_ptr cinfo)
{
/* no work in 1-pass case */
}
/*
* Switch to a new external colormap between output passes.
* Shouldn't get to this module!
*/
METHODDEF(void)
new_color_map_1_quant (j_decompress_ptr cinfo)
{
ERREXIT(cinfo, JERR_MODE_CHANGE);
}
/*
* Module initialization routine for 1-pass color quantization.
*/
GLOBAL(void)
jinit_1pass_quantizer (j_decompress_ptr cinfo)
{
my_cquantize_ptr cquantize;
cquantize = (my_cquantize_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_cquantizer));
cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize;
cquantize->pub.start_pass = start_pass_1_quant;
cquantize->pub.finish_pass = finish_pass_1_quant;
cquantize->pub.new_color_map = new_color_map_1_quant;
cquantize->fserrors[0] = NULL; /* Flag FS workspace not allocated */
cquantize->odither[0] = NULL; /* Also flag odither arrays not allocated */
/* Make sure my internal arrays won't overflow */
if (cinfo->out_color_components > MAX_Q_COMPS)
ERREXIT1(cinfo, JERR_QUANT_COMPONENTS, MAX_Q_COMPS);
/* Make sure colormap indexes can be represented by JSAMPLEs */
if (cinfo->desired_number_of_colors > (MAXJSAMPLE+1))
ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXJSAMPLE+1);
/* Create the colormap and color index table. */
create_colormap(cinfo);
create_colorindex(cinfo);
/* Allocate Floyd-Steinberg workspace now if requested.
* We do this now since it is FAR storage and may affect the memory
* manager's space calculations. If the user changes to FS dither
* mode in a later pass, we will allocate the space then, and will
* possibly overrun the max_memory_to_use setting.
*/
if (cinfo->dither_mode == JDITHER_FS)
alloc_fs_workspace(cinfo);
}
#endif /* QUANT_1PASS_SUPPORTED */
--- NEW FILE: jinclude.h ---
/*
* jinclude.h
*
* Copyright (C) 1991-1994, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file exists to provide a single place to fix any problems with
* including the wrong system include files. (Common problems are taken
* care of by the standard jconfig symbols, but on really weird systems
* you may have to edit this file.)
*
* NOTE: this file is NOT intended to be included by applications using the
* JPEG library. Most applications need only include jpeglib.h.
*/
/* Include auto-config file to find out which system include files we need. */
#include "jconfig.h" /* auto configuration options */
#define JCONFIG_INCLUDED /* so that jpeglib.h doesn't do it again */
/*
* We need the NULL macro and size_t typedef.
* On an ANSI-conforming system it is sufficient to include <stddef.h>.
* Otherwise, we get them from <stdlib.h> or <stdio.h>; we may have to
* pull in <sys/types.h> as well.
* Note that the core JPEG library does not require <stdio.h>;
* only the default error handler and data source/destination modules do.
* But we must pull it in because of the references to FILE in jpeglib.h.
* You can remove those references if you want to compile without <stdio.h>.
*/
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef NEED_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <stdio.h>
/*
* We need memory copying and zeroing functions, plus strncpy().
* ANSI and System V implementations declare these in <string.h>.
* BSD doesn't have the mem() functions, but it does have bcopy()/bzero().
* Some systems may declare memset and memcpy in <memory.h>.
*
* NOTE: we assume the size parameters to these functions are of type size_t.
* Change the casts in these macros if not!
*/
#ifdef NEED_BSD_STRINGS
#include <strings.h>
#define MEMZERO(target,size) bzero((void *)(target), (size_t)(size))
#define MEMCOPY(dest,src,size) bcopy((const void *)(src), (void *)(dest), (size_t)(size))
#else /* not BSD, assume ANSI/SysV string lib */
#include <string.h>
#define MEMZERO(target,size) memset((void *)(target), 0, (size_t)(size))
#define MEMCOPY(dest,src,size) memcpy((void *)(dest), (const void *)(src), (size_t)(size))
#endif
/*
* In ANSI C, and indeed any rational implementation, size_t is also the
* type returned by sizeof(). However, it seems there are some irrational
* implementations out there, in which sizeof() returns an int even though
* size_t is defined as long or unsigned long. To ensure consistent results
* we always use this SIZEOF() macro in place of using sizeof() directly.
*/
#define SIZEOF(object) ((size_t) sizeof(object))
/*
* The modules that use fread() and fwrite() always invoke them through
* these macros. On some systems you may need to twiddle the argument casts.
* CAUTION: argument order is different from underlying functions!
*/
#define JFREAD(file,buf,sizeofbuf) \
((size_t) fread((void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
#define JFWRITE(file,buf,sizeofbuf) \
((size_t) fwrite((const void *) (buf), (size_t) 1, (size_t) (sizeofbuf), (file)))
--- NEW FILE: jconfig.h ---
/* jconfig.h. Generated automatically by configure. */
/* jconfig.cfg --- source file edited by configure script */
/* see jconfig.doc for explanations */
#define HAVE_PROTOTYPES
#define HAVE_UNSIGNED_CHAR
#define HAVE_UNSIGNED_SHORT
#undef void
#undef const
#undef CHAR_IS_UNSIGNED
#define HAVE_STDDEF_H
#define HAVE_STDLIB_H
#undef NEED_BSD_STRINGS
#undef NEED_SYS_TYPES_H
#undef NEED_FAR_POINTERS
#undef NEED_SHORT_EXTERNAL_NAMES
/* Define this if you get warnings about undefined structures. */
#undef INCOMPLETE_TYPES_BROKEN
#ifdef JPEG_INTERNALS
#undef RIGHT_SHIFT_IS_UNSIGNED
#define INLINE __inline__
/* These are for configuring the JPEG memory manager. */
#undef DEFAULT_MAX_MEM
#undef NO_MKTEMP
#endif /* JPEG_INTERNALS */
#ifdef JPEG_CJPEG_DJPEG
#define BMP_SUPPORTED /* BMP image file format */
#define GIF_SUPPORTED /* GIF image file format */
#define PPM_SUPPORTED /* PBMPLUS PPM/PGM image file format */
#undef RLE_SUPPORTED /* Utah RLE image file format */
#define TARGA_SUPPORTED /* Targa image file format */
#undef TWO_FILE_COMMANDLINE
#undef NEED_SIGNAL_CATCHER
#undef DONT_USE_B_MODE
/* Define this if you want percent-done progress reports from cjpeg/djpeg. */
#undef PROGRESS_REPORT
#endif /* JPEG_CJPEG_DJPEG */
--- NEW FILE: jdatasrc.c ---
/*
* jdatasrc.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains decompression data source routines for the case of
* reading JPEG data from a file (or any stdio stream). While these routines
* are sufficient for most applications, some will want to use a different
* source manager.
* IMPORTANT: we assume that fread() will correctly transcribe an array of
* JOCTETs from 8-bit-wide elements on external storage. If char is wider
* than 8 bits on your machine, you may need to do some tweaking.
*/
/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
#include "jinclude.h"
#include "jpeglib.h"
#include "jerror.h"
/* Expanded data source object for stdio input */
typedef struct {
struct jpeg_source_mgr pub; /* public fields */
FILE * infile; /* source stream */
JOCTET * buffer; /* start of buffer */
boolean start_of_file; /* have we gotten any data yet? */
} my_source_mgr;
typedef my_source_mgr * my_src_ptr;
#define INPUT_BUF_SIZE 4096 /* choose an efficiently fread'able size */
/*
* Initialize source --- called by jpeg_read_header
* before any data is actually read.
*/
METHODDEF(void)
init_source (j_decompress_ptr cinfo)
{
my_src_ptr src = (my_src_ptr) cinfo->src;
/* We reset the empty-input-file flag for each image,
* but we don't clear the input buffer.
* This is correct behavior for reading a series of images from one source.
*/
src->start_of_file = TRUE;
}
/*
* Fill the input buffer --- called whenever buffer is emptied.
*
* In typical applications, this should read fresh data into the buffer
* (ignoring the current state of next_input_byte & bytes_in_buffer),
* reset the pointer & count to the start of the buffer, and return TRUE
* indicating that the buffer has been reloaded. It is not necessary to
* fill the buffer entirely, only to obtain at least one more byte.
*
* There is no such thing as an EOF return. If the end of the file has been
* reached, the routine has a choice of ERREXIT() or inserting fake data into
* the buffer. In most cases, generating a warning message and inserting a
* fake EOI marker is the best course of action --- this will allow the
* decompressor to output however much of the image is there. However,
* the resulting error message is misleading if the real problem is an empty
* input file, so we handle that case specially.
*
* In applications that need to be able to suspend compression due to input
* not being available yet, a FALSE return indicates that no more data can be
* obtained right now, but more may be forthcoming later. In this situation,
* the decompressor will return to its caller (with an indication of the
* number of scanlines it has read, if any). The application should resume
* decompression after it has loaded more data into the input buffer. Note
* that there are substantial restrictions on the use of suspension --- see
* the documentation.
*
* When suspending, the decompressor will back up to a convenient restart point
* (typically the start of the current MCU). next_input_byte & bytes_in_buffer
* indicate where the restart point will be if the current call returns FALSE.
* Data beyond this point must be rescanned after resumption, so move it to
* the front of the buffer rather than discarding it.
*/
METHODDEF(boolean)
fill_input_buffer (j_decompress_ptr cinfo)
{
my_src_ptr src = (my_src_ptr) cinfo->src;
size_t nbytes;
nbytes = JFREAD(src->infile, src->buffer, INPUT_BUF_SIZE);
if (nbytes <= 0) {
if (src->start_of_file) /* Treat empty input file as fatal error */
ERREXIT(cinfo, JERR_INPUT_EMPTY);
WARNMS(cinfo, JWRN_JPEG_EOF);
/* Insert a fake EOI marker */
src->buffer[0] = (JOCTET) 0xFF;
src->buffer[1] = (JOCTET) JPEG_EOI;
nbytes = 2;
}
src->pub.next_input_byte = src->buffer;
src->pub.bytes_in_buffer = nbytes;
src->start_of_file = FALSE;
return TRUE;
}
/*
* Skip data --- used to skip over a potentially large amount of
* uninteresting data (such as an APPn marker).
*
* Writers of suspendable-input applications must note that skip_input_data
* is not granted the right to give a suspension return. If the skip extends
* beyond the data currently in the buffer, the buffer can be marked empty so
* that the next read will cause a fill_input_buffer call that can suspend.
* Arranging for additional bytes to be discarded before reloading the input
* buffer is the application writer's problem.
*/
METHODDEF(void)
skip_input_data (j_decompress_ptr cinfo, long num_bytes)
{
my_src_ptr src = (my_src_ptr) cinfo->src;
/* Just a dumb implementation for now. Could use fseek() except
* it doesn't work on pipes. Not clear that being smart is worth
* any trouble anyway --- large skips are infrequent.
*/
if (num_bytes > 0) {
while (num_bytes > (long) src->pub.bytes_in_buffer) {
num_bytes -= (long) src->pub.bytes_in_buffer;
(void) fill_input_buffer(cinfo);
/* note we assume that fill_input_buffer will never return FALSE,
* so suspension need not be handled.
*/
}
src->pub.next_input_byte += (size_t) num_bytes;
src->pub.bytes_in_buffer -= (size_t) num_bytes;
}
}
/*
* An additional method that can be provided by data source modules is the
* resync_to_restart method for error recovery in the presence of RST markers.
* For the moment, this source module just uses the default resync method
* provided by the JPEG library. That method assumes that no backtracking
* is possible.
*/
/*
* Terminate source --- called by jpeg_finish_decompress
* after all data has been read. Often a no-op.
*
* NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
* application must deal with any cleanup that should happen even
* for error exit.
*/
METHODDEF(void)
term_source (j_decompress_ptr cinfo)
{
/* no work necessary here */
}
/*
* Prepare for input from a stdio stream.
* The caller must have already opened the stream, and is responsible
* for closing it after finishing decompression.
*/
GLOBAL(void)
jpeg_stdio_src (j_decompress_ptr cinfo, FILE * infile)
{
my_src_ptr src;
/* The source object and input buffer are made permanent so that a series
* of JPEG images can be read from the same file by calling jpeg_stdio_src
* only before the first one. (If we discarded the buffer at the end of
* one image, we'd likely lose the start of the next one.)
* This makes it unsafe to use this manager and a different source
* manager serially with the same JPEG object. Caveat programmer.
*/
if (cinfo->src == NULL) { /* first time for this JPEG object? */
cinfo->src = (struct jpeg_source_mgr *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
SIZEOF(my_source_mgr));
src = (my_src_ptr) cinfo->src;
src->buffer = (JOCTET *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
INPUT_BUF_SIZE * SIZEOF(JOCTET));
}
src = (my_src_ptr) cinfo->src;
src->pub.init_source = init_source;
src->pub.fill_input_buffer = fill_input_buffer;
src->pub.skip_input_data = skip_input_data;
src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
src->pub.term_source = term_source;
src->infile = infile;
src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
src->pub.next_input_byte = NULL; /* until buffer loaded */
}
--- NEW FILE: jmorecfg.h ---
/*
* jmorecfg.h
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains additional configuration options that customize the
* JPEG software for special applications or support machine-dependent
* optimizations. Most users will not need to touch this file.
*/
/*
* Define BITS_IN_JSAMPLE as either
* 8 for 8-bit sample values (the usual setting)
* 12 for 12-bit sample values
* Only 8 and 12 are legal data precisions for lossy JPEG according to the
* JPEG standard, and the IJG code does not support anything else!
* We do not support run-time selection of data precision, sorry.
*/
#define BITS_IN_JSAMPLE 8 /* use 8 or 12 */
/*
* Maximum number of components (color channels) allowed in JPEG image.
* To meet the letter of the JPEG spec, set this to 255. However, darn
* few applications need more than 4 channels (maybe 5 for CMYK + alpha
* mask). We recommend 10 as a reasonable compromise; use 4 if you are
* really short on memory. (Each allowed component costs a hundred or so
* bytes of storage, whether actually used in an image or not.)
*/
#define MAX_COMPONENTS 10 /* maximum number of image components */
/*
* Basic data types.
* You may need to change these if you have a machine with unusual data
* type sizes; for example, "char" not 8 bits, "short" not 16 bits,
* or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits,
* but it had better be at least 16.
*/
/* Representation of a single sample (pixel element value).
* We frequently allocate large arrays of these, so it's important to keep
* them small. But if you have memory to burn and access to char or short
* arrays is very slow on your hardware, you might want to change these.
*/
#if BITS_IN_JSAMPLE == 8
/* JSAMPLE should be the smallest type that will hold the values 0..255.
* You can use a signed char by having GETJSAMPLE mask it with 0xFF.
*/
#ifdef HAVE_UNSIGNED_CHAR
typedef unsigned char JSAMPLE;
#define GETJSAMPLE(value) ((int) (value))
#else /* not HAVE_UNSIGNED_CHAR */
typedef char JSAMPLE;
#ifdef CHAR_IS_UNSIGNED
#define GETJSAMPLE(value) ((int) (value))
#else
#define GETJSAMPLE(value) ((int) (value) & 0xFF)
#endif /* CHAR_IS_UNSIGNED */
#endif /* HAVE_UNSIGNED_CHAR */
#define MAXJSAMPLE 255
#define CENTERJSAMPLE 128
#endif /* BITS_IN_JSAMPLE == 8 */
#if BITS_IN_JSAMPLE == 12
/* JSAMPLE should be the smallest type that will hold the values 0..4095.
* On nearly all machines "short" will do nicely.
*/
typedef short JSAMPLE;
#define GETJSAMPLE(value) ((int) (value))
#define MAXJSAMPLE 4095
#define CENTERJSAMPLE 2048
#endif /* BITS_IN_JSAMPLE == 12 */
/* Representation of a DCT frequency coefficient.
* This should be a signed value of at least 16 bits; "short" is usually OK.
* Again, we allocate large arrays of these, but you can change to int
* if you have memory to burn and "short" is really slow.
*/
typedef short JCOEF;
/* Compressed datastreams are represented as arrays of JOCTET.
* These must be EXACTLY 8 bits wide, at least once they are written to
* external storage. Note that when using the stdio data source/destination
* managers, this is also the data type passed to fread/fwrite.
*/
#ifdef HAVE_UNSIGNED_CHAR
typedef unsigned char JOCTET;
#define GETJOCTET(value) (value)
#else /* not HAVE_UNSIGNED_CHAR */
typedef char JOCTET;
#ifdef CHAR_IS_UNSIGNED
#define GETJOCTET(value) (value)
#else
#define GETJOCTET(value) ((value) & 0xFF)
#endif /* CHAR_IS_UNSIGNED */
#endif /* HAVE_UNSIGNED_CHAR */
/* These typedefs are used for various table entries and so forth.
* They must be at least as wide as specified; but making them too big
* won't cost a huge amount of memory, so we don't provide special
* extraction code like we did for JSAMPLE. (In other words, these
* typedefs live at a different point on the speed/space tradeoff curve.)
*/
/* UINT8 must hold at least the values 0..255. */
#ifdef HAVE_UNSIGNED_CHAR
typedef unsigned char UINT8;
#else /* not HAVE_UNSIGNED_CHAR */
#ifdef CHAR_IS_UNSIGNED
typedef char UINT8;
#else /* not CHAR_IS_UNSIGNED */
typedef short UINT8;
#endif /* CHAR_IS_UNSIGNED */
#endif /* HAVE_UNSIGNED_CHAR */
/* UINT16 must hold at least the values 0..65535. */
#ifdef HAVE_UNSIGNED_SHORT
typedef unsigned short UINT16;
#else /* not HAVE_UNSIGNED_SHORT */
typedef unsigned int UINT16;
#endif /* HAVE_UNSIGNED_SHORT */
/* INT16 must hold at least the values -32768..32767. */
#ifndef XMD_H /* X11/xmd.h correctly defines INT16 */
typedef short INT16;
#endif
/* INT32 must hold at least signed 32-bit values. */
#ifndef XMD_H /* X11/xmd.h correctly defines INT32 */
typedef long INT32;
#endif
/* Datatype used for image dimensions. The JPEG standard only supports
* images up to 64K*64K due to 16-bit fields in SOF markers. Therefore
* "unsigned int" is sufficient on all machines. However, if you need to
* handle larger images and you don't mind deviating from the spec, you
* can change this datatype.
*/
typedef unsigned int JDIMENSION;
#define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */
/* These macros are used in all function definitions and extern declarations.
* You could modify them if you need to change function linkage conventions;
* in particular, you'll need to do that to make the library a Windows DLL.
* Another application is to make all functions global for use with debuggers
* or code profilers that require it.
*/
/* a function called through method pointers: */
#define METHODDEF(type) static type
/* a function used only in its module: */
#define LOCAL(type) static type
/* a function referenced thru EXTERNs: */
#define GLOBAL(type) type
/* a reference to a GLOBAL function: */
#define EXTERN(type) extern type
/* This macro is used to declare a "method", that is, a function pointer.
* We want to supply prototype parameters if the compiler can cope.
* Note that the arglist parameter must be parenthesized!
* Again, you can customize this if you need special linkage keywords.
*/
#ifdef HAVE_PROTOTYPES
#define JMETHOD(type,methodname,arglist) type (*methodname) arglist
#else
#define JMETHOD(type,methodname,arglist) type (*methodname) ()
#endif
/* Here is the pseudo-keyword for declaring pointers that must be "far"
* on 80x86 machines. Most of the specialized coding for 80x86 is handled
* by just saying "FAR *" where such a pointer is needed. In a few places
* explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
*/
#ifdef NEED_FAR_POINTERS
#define FAR far
#else
#define FAR
#endif
/*
* On a few systems, type boolean and/or its values FALSE, TRUE may appear
* in standard header files. Or you may have conflicts with application-
* specific header files that you want to include together with these files.
* Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
*/
#ifndef HAVE_BOOLEAN
typedef int boolean;
#endif
#ifndef FALSE /* in case these macros already exist */
#define FALSE 0 /* values of boolean */
#endif
#ifndef TRUE
#define TRUE 1
#endif
/*
* The remaining options affect code selection within the JPEG library,
* but they don't need to be visible to most applications using the library.
* To minimize application namespace pollution, the symbols won't be
* defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
*/
#ifdef JPEG_INTERNALS
#define JPEG_INTERNAL_OPTIONS
#endif
#ifdef JPEG_INTERNAL_OPTIONS
/*
* These defines indicate whether to include various optional functions.
* Undefining some of these symbols will produce a smaller but less capable
* library. Note that you can leave certain source files out of the
* compilation/linking process if you've #undef'd the corresponding symbols.
* (You may HAVE to do that if your compiler doesn't like null source files.)
*/
/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */
/* Capability options common to encoder and decoder: */
#define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */
#define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */
#define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */
/* Encoder capability options: */
#undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
#define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */
/* Note: if you selected 12-bit data precision, it is dangerous to turn off
* ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit
* precision, so jchuff.c normally uses entropy optimization to compute
* usable tables for higher precision. If you don't want to do optimization,
* you'll have to supply different default Huffman tables.
* The exact same statements apply for progressive JPEG: the default tables
* don't work for progressive mode. (This may get fixed, however.)
*/
#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */
/* Decoder capability options: */
#undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
#define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
#define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */
#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */
#define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */
#undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */
#define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */
#define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */
#define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */
/* more capability options later, no doubt */
/*
* Ordering of RGB data in scanlines passed to or from the application.
* If your application wants to deal with data in the order B,G,R, just
* change these macros. You can also deal with formats such as R,G,B,X
* (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing
* the offsets will also change the order in which colormap data is organized.
* RESTRICTIONS:
* 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
* 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
* useful if you are using JPEG color spaces other than YCbCr or grayscale.
* 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
* is not 3 (they don't understand about dummy color components!). So you
* can't use color quantization if you change that value.
*/
#define RGB_RED 0 /* Offset of Red in an RGB scanline element */
#define RGB_GREEN 1 /* Offset of Green */
#define RGB_BLUE 2 /* Offset of Blue */
#define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */
/* Definitions for speed-related optimizations. */
/* If your compiler supports inline functions, define INLINE
* as the inline keyword; otherwise define it as empty.
*/
#ifndef INLINE
#ifdef __GNUC__ /* for instance, GNU C knows about inline */
#define INLINE __inline__
#endif
#ifndef INLINE
#define INLINE /* default is to define it as empty */
#endif
#endif
/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
* two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER
* as short on such a machine. MULTIPLIER must be at least 16 bits wide.
*/
#ifndef MULTIPLIER
#define MULTIPLIER int /* type for fastest integer multiply */
#endif
/* FAST_FLOAT should be either float or double, whichever is done faster
* by your compiler. (Note that this type is only used in the floating point
* DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
* Typically, float is faster in ANSI C compilers, while double is faster in
* pre-ANSI compilers (because they insist on converting to double anyway).
* The code below therefore chooses float if we have ANSI-style prototypes.
*/
#ifndef FAST_FLOAT
#ifdef HAVE_PROTOTYPES
#define FAST_FLOAT float
#else
#define FAST_FLOAT double
#endif
#endif
#endif /* JPEG_INTERNAL_OPTIONS */
--- NEW FILE: jdhuff.c ---
/*
* jdhuff.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains Huffman entropy decoding routines.
*
* Much of the complexity here has to do with supporting input suspension.
* If the data source module demands suspension, we want to be able to back
* up to the start of the current MCU. To do this, we copy state variables
* into local working storage, and update them back to the permanent
* storage only upon successful completion of an MCU.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdhuff.h" /* Declarations shared with jdphuff.c */
/*
* Expanded entropy decoder object for Huffman decoding.
*
* The savable_state subrecord contains fields that change within an MCU,
* but must not be updated permanently until we complete the MCU.
*/
typedef struct {
int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
} savable_state;
/* This macro is to work around compilers with missing or broken
* structure assignment. You'll need to fix this code if you have
* such a compiler and you change MAX_COMPS_IN_SCAN.
*/
#ifndef NO_STRUCT_ASSIGN
#define ASSIGN_STATE(dest,src) ((dest) = (src))
#else
#if MAX_COMPS_IN_SCAN == 4
#define ASSIGN_STATE(dest,src) \
((dest).last_dc_val[0] = (src).last_dc_val[0], \
(dest).last_dc_val[1] = (src).last_dc_val[1], \
(dest).last_dc_val[2] = (src).last_dc_val[2], \
(dest).last_dc_val[3] = (src).last_dc_val[3])
#endif
#endif
typedef struct {
struct jpeg_entropy_decoder pub; /* public fields */
/* These fields are loaded into local variables at start of each MCU.
* In case of suspension, we exit WITHOUT updating them.
*/
bitread_perm_state bitstate; /* Bit buffer at start of MCU */
savable_state saved; /* Other state at start of MCU */
/* These fields are NOT loaded into local working state. */
unsigned int restarts_to_go; /* MCUs left in this restart interval */
/* Pointers to derived tables (these workspaces have image lifespan) */
d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
/* Precalculated info set up by start_pass for use in decode_mcu: */
/* Pointers to derived tables to be used for each block within an MCU */
d_derived_tbl * dc_cur_tbls[D_MAX_BLOCKS_IN_MCU];
d_derived_tbl * ac_cur_tbls[D_MAX_BLOCKS_IN_MCU];
/* Whether we care about the DC and AC coefficient values for each block */
boolean dc_needed[D_MAX_BLOCKS_IN_MCU];
boolean ac_needed[D_MAX_BLOCKS_IN_MCU];
} huff_entropy_decoder;
typedef huff_entropy_decoder * huff_entropy_ptr;
/*
* Initialize for a Huffman-compressed scan.
*/
METHODDEF(void)
start_pass_huff_decoder (j_decompress_ptr cinfo)
{
huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
int ci, blkn, dctbl, actbl;
jpeg_component_info * compptr;
/* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG.
* This ought to be an error condition, but we make it a warning because
* there are some baseline files out there with all zeroes in these bytes.
*/
if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2-1 ||
cinfo->Ah != 0 || cinfo->Al != 0)
WARNMS(cinfo, JWRN_NOT_SEQUENTIAL);
for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
compptr = cinfo->cur_comp_info[ci];
dctbl = compptr->dc_tbl_no;
actbl = compptr->ac_tbl_no;
/* Compute derived values for Huffman tables */
/* We may do this more than once for a table, but it's not expensive */
jpeg_make_d_derived_tbl(cinfo, TRUE, dctbl,
& entropy->dc_derived_tbls[dctbl]);
jpeg_make_d_derived_tbl(cinfo, FALSE, actbl,
& entropy->ac_derived_tbls[actbl]);
/* Initialize DC predictions to 0 */
entropy->saved.last_dc_val[ci] = 0;
}
/* Precalculate decoding info for each block in an MCU of this scan */
for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
ci = cinfo->MCU_membership[blkn];
compptr = cinfo->cur_comp_info[ci];
/* Precalculate which table to use for each block */
entropy->dc_cur_tbls[blkn] = entropy->dc_derived_tbls[compptr->dc_tbl_no];
entropy->ac_cur_tbls[blkn] = entropy->ac_derived_tbls[compptr->ac_tbl_no];
/* Decide whether we really care about the coefficient values */
if (compptr->component_needed) {
entropy->dc_needed[blkn] = TRUE;
/* we don't need the ACs if producing a 1/8th-size image */
entropy->ac_needed[blkn] = (compptr->DCT_scaled_size > 1);
} else {
entropy->dc_needed[blkn] = entropy->ac_needed[blkn] = FALSE;
}
}
/* Initialize bitread state variables */
entropy->bitstate.bits_left = 0;
entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */
entropy->pub.insufficient_data = FALSE;
/* Initialize restart counter */
entropy->restarts_to_go = cinfo->restart_interval;
}
/*
* Compute the derived values for a Huffman table.
* This routine also performs some validation checks on the table.
*
* Note this is also used by jdphuff.c.
*/
GLOBAL(void)
jpeg_make_d_derived_tbl (j_decompress_ptr cinfo, boolean isDC, int tblno,
d_derived_tbl ** pdtbl)
{
JHUFF_TBL *htbl;
d_derived_tbl *dtbl;
int p, i, l, si, numsymbols;
int lookbits, ctr;
char huffsize[257];
unsigned int huffcode[257];
unsigned int code;
/* Note that huffsize[] and huffcode[] are filled in code-length order,
* paralleling the order of the symbols themselves in htbl->huffval[].
*/
/* Find the input Huffman table */
if (tblno < 0 || tblno >= NUM_HUFF_TBLS)
ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
htbl =
isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno];
if (htbl == NULL)
ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
/* Allocate a workspace if we haven't already done so. */
if (*pdtbl == NULL)
*pdtbl = (d_derived_tbl *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(d_derived_tbl));
dtbl = *pdtbl;
dtbl->pub = htbl; /* fill in back link */
/* Figure C.1: make table of Huffman code length for each symbol */
p = 0;
for (l = 1; l <= 16; l++) {
i = (int) htbl->bits[l];
if (i < 0 || p + i > 256) /* protect against table overrun */
ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
while (i--)
huffsize[p++] = (char) l;
}
huffsize[p] = 0;
numsymbols = p;
/* Figure C.2: generate the codes themselves */
/* We also validate that the counts represent a legal Huffman code tree. */
code = 0;
si = huffsize[0];
p = 0;
while (huffsize[p]) {
while (((int) huffsize[p]) == si) {
huffcode[p++] = code;
code++;
}
/* code is now 1 more than the last code used for codelength si; but
* it must still fit in si bits, since no code is allowed to be all ones.
*/
if (((INT32) code) >= (((INT32) 1) << si))
ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
code <<= 1;
si++;
}
/* Figure F.15: generate decoding tables for bit-sequential decoding */
p = 0;
for (l = 1; l <= 16; l++) {
if (htbl->bits[l]) {
/* valoffset[l] = huffval[] index of 1st symbol of code length l,
* minus the minimum code of length l
*/
dtbl->valoffset[l] = (INT32) p - (INT32) huffcode[p];
p += htbl->bits[l];
dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */
} else {
dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
}
}
dtbl->maxcode[17] = 0xFFFFFL; /* ensures jpeg_huff_decode terminates */
/* Compute lookahead tables to speed up decoding.
* First we set all the table entries to 0, indicating "too long";
* then we iterate through the Huffman codes that are short enough and
* fill in all the entries that correspond to bit sequences starting
* with that code.
*/
MEMZERO(dtbl->look_nbits, SIZEOF(dtbl->look_nbits));
p = 0;
for (l = 1; l <= HUFF_LOOKAHEAD; l++) {
for (i = 1; i <= (int) htbl->bits[l]; i++, p++) {
/* l = current code's length, p = its index in huffcode[] & huffval[]. */
/* Generate left-justified code followed by all possible bit sequences */
lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l);
for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) {
dtbl->look_nbits[lookbits] = l;
dtbl->look_sym[lookbits] = htbl->huffval[p];
lookbits++;
}
}
}
/* Validate symbols as being reasonable.
* For AC tables, we make no check, but accept all byte values 0..255.
* For DC tables, we require the symbols to be in range 0..15.
* (Tighter bounds could be applied depending on the data depth and mode,
* but this is sufficient to ensure safe decoding.)
*/
if (isDC) {
for (i = 0; i < numsymbols; i++) {
int sym = htbl->huffval[i];
if (sym < 0 || sym > 15)
ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
}
}
}
/*
* Out-of-line code for bit fetching (shared with jdphuff.c).
* See jdhuff.h for info about usage.
* Note: current values of get_buffer and bits_left are passed as parameters,
* but are returned in the corresponding fields of the state struct.
*
* On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width
* of get_buffer to be used. (On machines with wider words, an even larger
* buffer could be used.) However, on some machines 32-bit shifts are
* quite slow and take time proportional to the number of places shifted.
* (This is true with most PC compilers, for instance.) In this case it may
* be a win to set MIN_GET_BITS to the minimum value of 15. This reduces the
* average shift distance at the cost of more calls to jpeg_fill_bit_buffer.
*/
#ifdef SLOW_SHIFT_32
#define MIN_GET_BITS 15 /* minimum allowable value */
#else
#define MIN_GET_BITS (BIT_BUF_SIZE-7)
#endif
GLOBAL(boolean)
jpeg_fill_bit_buffer (bitread_working_state * state,
register bit_buf_type get_buffer, register int bits_left,
int nbits)
/* Load up the bit buffer to a depth of at least nbits */
{
/* Copy heavily used state fields into locals (hopefully registers) */
register const JOCTET * next_input_byte = state->next_input_byte;
register size_t bytes_in_buffer = state->bytes_in_buffer;
j_decompress_ptr cinfo = state->cinfo;
/* Attempt to load at least MIN_GET_BITS bits into get_buffer. */
/* (It is assumed that no request will be for more than that many bits.) */
/* We fail to do so only if we hit a marker or are forced to suspend. */
if (cinfo->unread_marker == 0) { /* cannot advance past a marker */
while (bits_left < MIN_GET_BITS) {
register int c;
/* Attempt to read a byte */
if (bytes_in_buffer == 0) {
if (! (*cinfo->src->fill_input_buffer) (cinfo))
return FALSE;
next_input_byte = cinfo->src->next_input_byte;
bytes_in_buffer = cinfo->src->bytes_in_buffer;
}
bytes_in_buffer--;
c = GETJOCTET(*next_input_byte++);
/* If it's 0xFF, check and discard stuffed zero byte */
if (c == 0xFF) {
/* Loop here to discard any padding FF's on terminating marker,
* so that we can save a valid unread_marker value. NOTE: we will
* accept multiple FF's followed by a 0 as meaning a single FF data
* byte. This data pattern is not valid according to the standard.
*/
do {
if (bytes_in_buffer == 0) {
if (! (*cinfo->src->fill_input_buffer) (cinfo))
return FALSE;
next_input_byte = cinfo->src->next_input_byte;
bytes_in_buffer = cinfo->src->bytes_in_buffer;
}
bytes_in_buffer--;
c = GETJOCTET(*next_input_byte++);
} while (c == 0xFF);
if (c == 0) {
/* Found FF/00, which represents an FF data byte */
c = 0xFF;
} else {
/* Oops, it's actually a marker indicating end of compressed data.
* Save the marker code for later use.
* Fine point: it might appear that we should save the marker into
* bitread working state, not straight into permanent state. But
* once we have hit a marker, we cannot need to suspend within the
* current MCU, because we will read no more bytes from the data
* source. So it is OK to update permanent state right away.
*/
cinfo->unread_marker = c;
/* See if we need to insert some fake zero bits. */
goto no_more_bytes;
}
}
/* OK, load c into get_buffer */
get_buffer = (get_buffer << 8) | c;
bits_left += 8;
} /* end while */
} else {
no_more_bytes:
/* We get here if we've read the marker that terminates the compressed
* data segment. There should be enough bits in the buffer register
* to satisfy the request; if so, no problem.
*/
if (nbits > bits_left) {
/* Uh-oh. Report corrupted data to user and stuff zeroes into
* the data stream, so that we can produce some kind of image.
* We use a nonvolatile flag to ensure that only one warning message
* appears per data segment.
*/
if (! cinfo->entropy->insufficient_data) {
WARNMS(cinfo, JWRN_HIT_MARKER);
cinfo->entropy->insufficient_data = TRUE;
}
/* Fill the buffer with zero bits */
get_buffer <<= MIN_GET_BITS - bits_left;
bits_left = MIN_GET_BITS;
}
}
/* Unload the local registers */
state->next_input_byte = next_input_byte;
state->bytes_in_buffer = bytes_in_buffer;
state->get_buffer = get_buffer;
state->bits_left = bits_left;
return TRUE;
}
/*
* Out-of-line code for Huffman code decoding.
* See jdhuff.h for info about usage.
*/
GLOBAL(int)
jpeg_huff_decode (bitread_working_state * state,
register bit_buf_type get_buffer, register int bits_left,
d_derived_tbl * htbl, int min_bits)
{
register int l = min_bits;
register INT32 code;
/* HUFF_DECODE has determined that the code is at least min_bits */
/* bits long, so fetch that many bits in one swoop. */
CHECK_BIT_BUFFER(*state, l, return -1);
code = GET_BITS(l);
/* Collect the rest of the Huffman code one bit at a time. */
/* This is per Figure F.16 in the JPEG spec. */
while (code > htbl->maxcode[l]) {
code <<= 1;
CHECK_BIT_BUFFER(*state, 1, return -1);
code |= GET_BITS(1);
l++;
}
/* Unload the local registers */
state->get_buffer = get_buffer;
state->bits_left = bits_left;
/* With garbage input we may reach the sentinel value l = 17. */
if (l > 16) {
WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE);
return 0; /* fake a zero as the safest result */
}
return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ];
}
/*
* Figure F.12: extend sign bit.
* On some machines, a shift and add will be faster than a table lookup.
*/
#ifdef AVOID_TABLES
#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x))
#else
#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
static const int extend_test[16] = /* entry n is 2**(n-1) */
{ 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
{ 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 };
#endif /* AVOID_TABLES */
/*
* Check for a restart marker & resynchronize decoder.
* Returns FALSE if must suspend.
*/
LOCAL(boolean)
process_restart (j_decompress_ptr cinfo)
{
huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
int ci;
/* Throw away any unused bits remaining in bit buffer; */
/* include any full bytes in next_marker's count of discarded bytes */
cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
entropy->bitstate.bits_left = 0;
/* Advance past the RSTn marker */
if (! (*cinfo->marker->read_restart_marker) (cinfo))
return FALSE;
/* Re-initialize DC predictions to 0 */
for (ci = 0; ci < cinfo->comps_in_scan; ci++)
entropy->saved.last_dc_val[ci] = 0;
/* Reset restart counter */
entropy->restarts_to_go = cinfo->restart_interval;
/* Reset out-of-data flag, unless read_restart_marker left us smack up
* against a marker. In that case we will end up treating the next data
* segment as empty, and we can avoid producing bogus output pixels by
* leaving the flag set.
*/
if (cinfo->unread_marker == 0)
entropy->pub.insufficient_data = FALSE;
return TRUE;
}
/*
* Decode and return one MCU's worth of Huffman-compressed coefficients.
* The coefficients are reordered from zigzag order into natural array order,
* but are not dequantized.
*
* The i'th block of the MCU is stored into the block pointed to by
* MCU_data[i]. WE ASSUME THIS AREA HAS BEEN ZEROED BY THE CALLER.
* (Wholesale zeroing is usually a little faster than retail...)
*
* Returns FALSE if data source requested suspension. In that case no
* changes have been made to permanent state. (Exception: some output
* coefficients may already have been assigned. This is harmless for
* this module, since we'll just re-assign them on the next call.)
*/
METHODDEF(boolean)
decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
{
huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
int blkn;
BITREAD_STATE_VARS;
savable_state state;
/* Process restart marker if needed; may have to suspend */
if (cinfo->restart_interval) {
if (entropy->restarts_to_go == 0)
if (! process_restart(cinfo))
return FALSE;
}
/* If we've run out of data, just leave the MCU set to zeroes.
* This way, we return uniform gray for the remainder of the segment.
*/
if (! entropy->pub.insufficient_data) {
/* Load up working state */
BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
ASSIGN_STATE(state, entropy->saved);
/* Outer loop handles each block in the MCU */
for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
JBLOCKROW block = MCU_data[blkn];
d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn];
d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn];
register int s, k, r;
/* Decode a single block's worth of coefficients */
/* Section F.2.2.1: decode the DC coefficient difference */
HUFF_DECODE(s, br_state, dctbl, return FALSE, label1);
if (s) {
CHECK_BIT_BUFFER(br_state, s, return FALSE);
r = GET_BITS(s);
s = HUFF_EXTEND(r, s);
}
if (entropy->dc_needed[blkn]) {
/* Convert DC difference to actual value, update last_dc_val */
int ci = cinfo->MCU_membership[blkn];
s += state.last_dc_val[ci];
state.last_dc_val[ci] = s;
/* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */
(*block)[0] = (JCOEF) s;
}
if (entropy->ac_needed[blkn]) {
/* Section F.2.2.2: decode the AC coefficients */
/* Since zeroes are skipped, output area must be cleared beforehand */
for (k = 1; k < DCTSIZE2; k++) {
HUFF_DECODE(s, br_state, actbl, return FALSE, label2);
r = s >> 4;
s &= 15;
if (s) {
k += r;
CHECK_BIT_BUFFER(br_state, s, return FALSE);
r = GET_BITS(s);
s = HUFF_EXTEND(r, s);
/* Output coefficient in natural (dezigzagged) order.
* Note: the extra entries in jpeg_natural_order[] will save us
* if k >= DCTSIZE2, which could happen if the data is corrupted.
*/
(*block)[jpeg_natural_order[k]] = (JCOEF) s;
} else {
if (r != 15)
break;
k += 15;
}
}
} else {
/* Section F.2.2.2: decode the AC coefficients */
/* In this path we just discard the values */
for (k = 1; k < DCTSIZE2; k++) {
HUFF_DECODE(s, br_state, actbl, return FALSE, label3);
r = s >> 4;
s &= 15;
if (s) {
k += r;
CHECK_BIT_BUFFER(br_state, s, return FALSE);
DROP_BITS(s);
} else {
if (r != 15)
break;
k += 15;
}
}
}
}
/* Completed MCU, so update state */
BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
ASSIGN_STATE(entropy->saved, state);
}
/* Account for restart interval (no-op if not using restarts) */
entropy->restarts_to_go--;
return TRUE;
}
/*
* Module initialization routine for Huffman entropy decoding.
*/
GLOBAL(void)
jinit_huff_decoder (j_decompress_ptr cinfo)
{
huff_entropy_ptr entropy;
int i;
entropy = (huff_entropy_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(huff_entropy_decoder));
cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
entropy->pub.start_pass = start_pass_huff_decoder;
entropy->pub.decode_mcu = decode_mcu;
/* Mark tables unallocated */
for (i = 0; i < NUM_HUFF_TBLS; i++) {
entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
}
}
--- NEW FILE: jidctint.c ---
/*
* jidctint.c
*
* Copyright (C) 1991-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains a slow-but-accurate integer implementation of the
* inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
* must also perform dequantization of the input coefficients.
*
* A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
* on each row (or vice versa, but it's more convenient to emit a row at
* a time). Direct algorithms are also available, but they are much more
* complex and seem not to be any faster when reduced to code.
*
* This implementation is based on an algorithm described in
* C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
* Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
* Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
* The primary algorithm described there uses 11 multiplies and 29 adds.
* We use their alternate method with 12 multiplies and 32 adds.
* The advantage of this method is that no data path contains more than one
* multiplication; this allows a very simple and accurate implementation in
* scaled fixed-point arithmetic, with a minimal number of shifts.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
#ifdef DCT_ISLOW_SUPPORTED
/*
* This module is specialized to the case DCTSIZE = 8.
*/
#if DCTSIZE != 8
Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
#endif
/*
* The poop on this scaling stuff is as follows:
*
* Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
* larger than the true IDCT outputs. The final outputs are therefore
* a factor of N larger than desired; since N=8 this can be cured by
* a simple right shift at the end of the algorithm. The advantage of
* this arrangement is that we save two multiplications per 1-D IDCT,
* because the y0 and y4 inputs need not be divided by sqrt(N).
*
* We have to do addition and subtraction of the integer inputs, which
* is no problem, and multiplication by fractional constants, which is
* a problem to do in integer arithmetic. We multiply all the constants
* by CONST_SCALE and convert them to integer constants (thus retaining
* CONST_BITS bits of precision in the constants). After doing a
* multiplication we have to divide the product by CONST_SCALE, with proper
* rounding, to produce the correct output. This division can be done
* cheaply as a right shift of CONST_BITS bits. We postpone shifting
* as long as possible so that partial sums can be added together with
* full fractional precision.
*
* The outputs of the first pass are scaled up by PASS1_BITS bits so that
* they are represented to better-than-integral precision. These outputs
* require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
* with the recommended scaling. (To scale up 12-bit sample data further, an
* intermediate INT32 array would be needed.)
*
* To avoid overflow of the 32-bit intermediate results in pass 2, we must
* have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
* shows that the values given below are the most effective.
*/
#if BITS_IN_JSAMPLE == 8
#define CONST_BITS 13
#define PASS1_BITS 2
#else
#define CONST_BITS 13
#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
#endif
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
* causing a lot of useless floating-point operations at run time.
* To get around this we use the following pre-calculated constants.
* If you change CONST_BITS you may want to add appropriate values.
* (With a reasonable C compiler, you can just rely on the FIX() macro...)
*/
#if CONST_BITS == 13
#define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
#define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
#define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
#define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
#define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
#define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
#define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
#define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
#else
#define FIX_0_298631336 FIX(0.298631336)
#define FIX_0_390180644 FIX(0.390180644)
#define FIX_0_541196100 FIX(0.541196100)
#define FIX_0_765366865 FIX(0.765366865)
#define FIX_0_899976223 FIX(0.899976223)
#define FIX_1_175875602 FIX(1.175875602)
#define FIX_1_501321110 FIX(1.501321110)
#define FIX_1_847759065 FIX(1.847759065)
#define FIX_1_961570560 FIX(1.961570560)
#define FIX_2_053119869 FIX(2.053119869)
#define FIX_2_562915447 FIX(2.562915447)
#define FIX_3_072711026 FIX(3.072711026)
#endif
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
* For 8-bit samples with the recommended scaling, all the variable
* and constant values involved are no more than 16 bits wide, so a
* 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
* For 12-bit samples, a full 32-bit multiplication will be needed.
*/
#if BITS_IN_JSAMPLE == 8
#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
#else
#define MULTIPLY(var,const) ((var) * (const))
#endif
/* Dequantize a coefficient by multiplying it by the multiplier-table
* entry; produce an int result. In this module, both inputs and result
* are 16 bits or less, so either int or short multiply will work.
*/
#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
/*
* Perform dequantization and inverse DCT on one block of coefficients.
*/
GLOBAL(void)
jpeg_idct_islow (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
INT32 tmp0, tmp1, tmp2, tmp3;
INT32 tmp10, tmp11, tmp12, tmp13;
INT32 z1, z2, z3, z4, z5;
JCOEFPTR inptr;
ISLOW_MULT_TYPE * quantptr;
int * wsptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[DCTSIZE2]; /* buffers data between passes */
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array. */
/* Note results are scaled up by sqrt(8) compared to a true IDCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; ctr--) {
/* Due to quantization, we will usually find that many of the input
* coefficients are zero, especially the AC terms. We can exploit this
* by short-circuiting the IDCT calculation for any column in which all
* the AC terms are zero. In that case each output is equal to the
* DC coefficient (with scale factor as needed).
* With typical images and quantization tables, half or more of the
* column DCT calculations can be simplified this way.
*/
if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 &&
inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 &&
inptr[DCTSIZE*7] == 0) {
/* AC terms all zero */
int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
wsptr[DCTSIZE*0] = dcval;
wsptr[DCTSIZE*1] = dcval;
wsptr[DCTSIZE*2] = dcval;
wsptr[DCTSIZE*3] = dcval;
wsptr[DCTSIZE*4] = dcval;
wsptr[DCTSIZE*5] = dcval;
wsptr[DCTSIZE*6] = dcval;
wsptr[DCTSIZE*7] = dcval;
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
continue;
}
/* Even part: reverse the even part of the forward DCT. */
/* The rotator is sqrt(2)*c(-6). */
z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
tmp0 = (z2 + z3) << CONST_BITS;
tmp1 = (z2 - z3) << CONST_BITS;
tmp10 = tmp0 + tmp3;
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
/* Odd part per figure 8; the matrix is unitary and hence its
* transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
*/
tmp0 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
tmp1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
tmp2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
z1 = tmp0 + tmp3;
z2 = tmp1 + tmp2;
z3 = tmp0 + tmp2;
z4 = tmp1 + tmp3;
z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
z3 += z5;
z4 += z5;
tmp0 += z1 + z3;
tmp1 += z2 + z4;
tmp2 += z2 + z3;
tmp3 += z1 + z4;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*7] = (int) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*1] = (int) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*6] = (int) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*5] = (int) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*3] = (int) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
wsptr[DCTSIZE*4] = (int) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
}
/* Pass 2: process rows from work array, store into output array. */
/* Note that we must descale the results by a factor of 8 == 2**3, */
/* and also undo the PASS1_BITS scaling. */
wsptr = workspace;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Rows of zeroes can be exploited in the same way as we did with columns.
* However, the column calculation has created many nonzero AC terms, so
* the simplification applies less often (typically 5% to 10% of the time).
* On machines with very fast multiplication, it's possible that the
* test takes more time than it's worth. In that case this section
* may be commented out.
*/
#ifndef NO_ZERO_ROW_TEST
if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 &&
wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
/* AC terms all zero */
JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
& RANGE_MASK];
outptr[0] = dcval;
outptr[1] = dcval;
outptr[2] = dcval;
outptr[3] = dcval;
outptr[4] = dcval;
outptr[5] = dcval;
outptr[6] = dcval;
outptr[7] = dcval;
wsptr += DCTSIZE; /* advance pointer to next row */
continue;
}
#endif
/* Even part: reverse the even part of the forward DCT. */
/* The rotator is sqrt(2)*c(-6). */
z2 = (INT32) wsptr[2];
z3 = (INT32) wsptr[6];
z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
tmp0 = ((INT32) wsptr[0] + (INT32) wsptr[4]) << CONST_BITS;
tmp1 = ((INT32) wsptr[0] - (INT32) wsptr[4]) << CONST_BITS;
tmp10 = tmp0 + tmp3;
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
/* Odd part per figure 8; the matrix is unitary and hence its
* transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
*/
tmp0 = (INT32) wsptr[7];
tmp1 = (INT32) wsptr[5];
tmp2 = (INT32) wsptr[3];
tmp3 = (INT32) wsptr[1];
z1 = tmp0 + tmp3;
z2 = tmp1 + tmp2;
z3 = tmp0 + tmp2;
z4 = tmp1 + tmp3;
z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
z3 += z5;
z4 += z5;
tmp0 += z1 + z3;
tmp1 += z2 + z4;
tmp2 += z2 + z3;
tmp3 += z1 + z4;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp3,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[7] = range_limit[(int) DESCALE(tmp10 - tmp3,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[1] = range_limit[(int) DESCALE(tmp11 + tmp2,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[6] = range_limit[(int) DESCALE(tmp11 - tmp2,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[2] = range_limit[(int) DESCALE(tmp12 + tmp1,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[5] = range_limit[(int) DESCALE(tmp12 - tmp1,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[3] = range_limit[(int) DESCALE(tmp13 + tmp0,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
outptr[4] = range_limit[(int) DESCALE(tmp13 - tmp0,
CONST_BITS+PASS1_BITS+3)
& RANGE_MASK];
wsptr += DCTSIZE; /* advance pointer to next row */
}
}
#endif /* DCT_ISLOW_SUPPORTED */
--- NEW FILE: jdapimin.c ---
/*
* jdapimin.c
*
* Copyright (C) 1994-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains application interface code for the decompression half
* of the JPEG library. These are the "minimum" API routines that may be
* needed in either the normal full-decompression case or the
* transcoding-only case.
*
* Most of the routines intended to be called directly by an application
* are in this file or in jdapistd.c. But also see jcomapi.c for routines
* shared by compression and decompression, and jdtrans.c for the transcoding
* case.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/*
* Initialization of a JPEG decompression object.
* The error manager must already be set up (in case memory manager fails).
*/
GLOBAL(void)
jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, size_t structsize)
{
int i;
/* Guard against version mismatches between library and caller. */
cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
if (version != JPEG_LIB_VERSION)
ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
if (structsize != SIZEOF(struct jpeg_decompress_struct))
ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
(int) SIZEOF(struct jpeg_decompress_struct), (int) structsize);
/* For debugging purposes, we zero the whole master structure.
* But the application has already set the err pointer, and may have set
* client_data, so we have to save and restore those fields.
* Note: if application hasn't set client_data, tools like Purify may
* complain here.
*/
{
struct jpeg_error_mgr * err = cinfo->err;
void * client_data = cinfo->client_data; /* ignore Purify complaint here */
MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));
cinfo->err = err;
cinfo->client_data = client_data;
}
cinfo->is_decompressor = TRUE;
/* Initialize a memory manager instance for this object */
jinit_memory_mgr((j_common_ptr) cinfo);
/* Zero out pointers to permanent structures. */
cinfo->progress = NULL;
cinfo->src = NULL;
for (i = 0; i < NUM_QUANT_TBLS; i++)
cinfo->quant_tbl_ptrs[i] = NULL;
for (i = 0; i < NUM_HUFF_TBLS; i++) {
cinfo->dc_huff_tbl_ptrs[i] = NULL;
cinfo->ac_huff_tbl_ptrs[i] = NULL;
}
/* Initialize marker processor so application can override methods
* for COM, APPn markers before calling jpeg_read_header.
*/
cinfo->marker_list = NULL;
jinit_marker_reader(cinfo);
/* And initialize the overall input controller. */
jinit_input_controller(cinfo);
/* OK, I'm ready */
cinfo->global_state = DSTATE_START;
}
/*
* Destruction of a JPEG decompression object
*/
GLOBAL(void)
jpeg_destroy_decompress (j_decompress_ptr cinfo)
{
jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
}
/*
* Abort processing of a JPEG decompression operation,
* but don't destroy the object itself.
*/
GLOBAL(void)
jpeg_abort_decompress (j_decompress_ptr cinfo)
{
jpeg_abort((j_common_ptr) cinfo); /* use common routine */
}
/*
* Set default decompression parameters.
*/
LOCAL(void)
default_decompress_parms (j_decompress_ptr cinfo)
{
/* Guess the input colorspace, and set output colorspace accordingly. */
/* (Wish JPEG committee had provided a real way to specify this...) */
/* Note application may override our guesses. */
switch (cinfo->num_components) {
case 1:
cinfo->jpeg_color_space = JCS_GRAYSCALE;
cinfo->out_color_space = JCS_GRAYSCALE;
break;
case 3:
if (cinfo->saw_JFIF_marker) {
cinfo->jpeg_color_space = JCS_YCbCr; /* JFIF implies YCbCr */
} else if (cinfo->saw_Adobe_marker) {
switch (cinfo->Adobe_transform) {
case 0:
cinfo->jpeg_color_space = JCS_RGB;
break;
case 1:
cinfo->jpeg_color_space = JCS_YCbCr;
break;
default:
WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
break;
}
} else {
/* Saw no special markers, try to guess from the component IDs */
int cid0 = cinfo->comp_info[0].component_id;
int cid1 = cinfo->comp_info[1].component_id;
int cid2 = cinfo->comp_info[2].component_id;
if (cid0 == 1 && cid1 == 2 && cid2 == 3)
cinfo->jpeg_color_space = JCS_YCbCr; /* assume JFIF w/out marker */
else if (cid0 == 82 && cid1 == 71 && cid2 == 66)
cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */
else {
TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
}
}
/* Always guess RGB is proper output colorspace. */
cinfo->out_color_space = JCS_RGB;
break;
case 4:
if (cinfo->saw_Adobe_marker) {
switch (cinfo->Adobe_transform) {
case 0:
cinfo->jpeg_color_space = JCS_CMYK;
break;
case 2:
cinfo->jpeg_color_space = JCS_YCCK;
break;
default:
WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */
break;
}
} else {
/* No special markers, assume straight CMYK. */
cinfo->jpeg_color_space = JCS_CMYK;
}
cinfo->out_color_space = JCS_CMYK;
break;
default:
cinfo->jpeg_color_space = JCS_UNKNOWN;
cinfo->out_color_space = JCS_UNKNOWN;
break;
}
/* Set defaults for other decompression parameters. */
cinfo->scale_num = 1; /* 1:1 scaling */
cinfo->scale_denom = 1;
cinfo->output_gamma = 1.0;
cinfo->buffered_image = FALSE;
cinfo->raw_data_out = FALSE;
cinfo->dct_method = JDCT_DEFAULT;
cinfo->do_fancy_upsampling = TRUE;
cinfo->do_block_smoothing = TRUE;
cinfo->quantize_colors = FALSE;
/* We set these in case application only sets quantize_colors. */
cinfo->dither_mode = JDITHER_FS;
#ifdef QUANT_2PASS_SUPPORTED
cinfo->two_pass_quantize = TRUE;
#else
cinfo->two_pass_quantize = FALSE;
#endif
cinfo->desired_number_of_colors = 256;
cinfo->colormap = NULL;
/* Initialize for no mode change in buffered-image mode. */
cinfo->enable_1pass_quant = FALSE;
cinfo->enable_external_quant = FALSE;
cinfo->enable_2pass_quant = FALSE;
}
/*
* Decompression startup: read start of JPEG datastream to see what's there.
* Need only initialize JPEG object and supply a data source before calling.
*
* This routine will read as far as the first SOS marker (ie, actual start of
* compressed data), and will save all tables and parameters in the JPEG
* object. It will also initialize the decompression parameters to default
* values, and finally return JPEG_HEADER_OK. On return, the application may
* adjust the decompression parameters and then call jpeg_start_decompress.
* (Or, if the application only wanted to determine the image parameters,
* the data need not be decompressed. In that case, call jpeg_abort or
* jpeg_destroy to release any temporary space.)
* If an abbreviated (tables only) datastream is presented, the routine will
* return JPEG_HEADER_TABLES_ONLY upon reaching EOI. The application may then
* re-use the JPEG object to read the abbreviated image datastream(s).
* It is unnecessary (but OK) to call jpeg_abort in this case.
* The JPEG_SUSPENDED return code only occurs if the data source module
* requests suspension of the decompressor. In this case the application
* should load more source data and then re-call jpeg_read_header to resume
* processing.
* If a non-suspending data source is used and require_image is TRUE, then the
* return code need not be inspected since only JPEG_HEADER_OK is possible.
*
* This routine is now just a front end to jpeg_consume_input, with some
* extra error checking.
*/
GLOBAL(int)
jpeg_read_header (j_decompress_ptr cinfo, boolean require_image)
{
int retcode;
if (cinfo->global_state != DSTATE_START &&
cinfo->global_state != DSTATE_INHEADER)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
retcode = jpeg_consume_input(cinfo);
switch (retcode) {
case JPEG_REACHED_SOS:
retcode = JPEG_HEADER_OK;
break;
case JPEG_REACHED_EOI:
if (require_image) /* Complain if application wanted an image */
ERREXIT(cinfo, JERR_NO_IMAGE);
/* Reset to start state; it would be safer to require the application to
* call jpeg_abort, but we can't change it now for compatibility reasons.
* A side effect is to free any temporary memory (there shouldn't be any).
*/
jpeg_abort((j_common_ptr) cinfo); /* sets state = DSTATE_START */
retcode = JPEG_HEADER_TABLES_ONLY;
break;
case JPEG_SUSPENDED:
/* no work */
break;
}
return retcode;
}
/*
* Consume data in advance of what the decompressor requires.
* This can be called at any time once the decompressor object has
* been created and a data source has been set up.
*
* This routine is essentially a state machine that handles a couple
* of critical state-transition actions, namely initial setup and
* transition from header scanning to ready-for-start_decompress.
* All the actual input is done via the input controller's consume_input
* method.
*/
GLOBAL(int)
jpeg_consume_input (j_decompress_ptr cinfo)
{
int retcode = JPEG_SUSPENDED;
/* NB: every possible DSTATE value should be listed in this switch */
switch (cinfo->global_state) {
case DSTATE_START:
/* Start-of-datastream actions: reset appropriate modules */
(*cinfo->inputctl->reset_input_controller) (cinfo);
/* Initialize application's data source module */
(*cinfo->src->init_source) (cinfo);
cinfo->global_state = DSTATE_INHEADER;
/*FALLTHROUGH*/
case DSTATE_INHEADER:
retcode = (*cinfo->inputctl->consume_input) (cinfo);
if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
/* Set up default parameters based on header data */
default_decompress_parms(cinfo);
/* Set global state: ready for start_decompress */
cinfo->global_state = DSTATE_READY;
}
break;
case DSTATE_READY:
/* Can't advance past first SOS until start_decompress is called */
retcode = JPEG_REACHED_SOS;
break;
case DSTATE_PRELOAD:
case DSTATE_PRESCAN:
case DSTATE_SCANNING:
case DSTATE_RAW_OK:
case DSTATE_BUFIMAGE:
case DSTATE_BUFPOST:
case DSTATE_STOPPING:
retcode = (*cinfo->inputctl->consume_input) (cinfo);
break;
default:
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
}
return retcode;
}
/*
* Have we finished reading the input file?
*/
GLOBAL(boolean)
jpeg_input_complete (j_decompress_ptr cinfo)
{
/* Check for valid jpeg object */
if (cinfo->global_state < DSTATE_START ||
cinfo->global_state > DSTATE_STOPPING)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
return cinfo->inputctl->eoi_reached;
}
/*
* Is there more than one scan?
*/
GLOBAL(boolean)
jpeg_has_multiple_scans (j_decompress_ptr cinfo)
{
/* Only valid after jpeg_read_header completes */
if (cinfo->global_state < DSTATE_READY ||
cinfo->global_state > DSTATE_STOPPING)
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
return cinfo->inputctl->has_multiple_scans;
}
/*
* Finish JPEG decompression.
*
* This will normally just verify the file trailer and release temp storage.
*
* Returns FALSE if suspended. The return value need be inspected only if
* a suspending data source is used.
*/
GLOBAL(boolean)
jpeg_finish_decompress (j_decompress_ptr cinfo)
{
if ((cinfo->global_state == DSTATE_SCANNING ||
cinfo->global_state == DSTATE_RAW_OK) && ! cinfo->buffered_image) {
/* Terminate final pass of non-buffered mode */
if (cinfo->output_scanline < cinfo->output_height)
ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
(*cinfo->master->finish_output_pass) (cinfo);
cinfo->global_state = DSTATE_STOPPING;
} else if (cinfo->global_state == DSTATE_BUFIMAGE) {
/* Finishing after a buffered-image operation */
cinfo->global_state = DSTATE_STOPPING;
} else if (cinfo->global_state != DSTATE_STOPPING) {
/* STOPPING = repeat call after a suspension, anything else is error */
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
}
/* Read until EOI */
while (! cinfo->inputctl->eoi_reached) {
if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
return FALSE; /* Suspend, come back later */
}
/* Do final cleanup */
(*cinfo->src->term_source) (cinfo);
/* We can use jpeg_abort to release memory and reset global_state */
jpeg_abort((j_common_ptr) cinfo);
return TRUE;
}
--- NEW FILE: jmemnobs.c ---
/*
* jmemnobs.c
*
* Copyright (C) 1992-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file provides a really simple implementation of the system-
* dependent portion of the JPEG memory manager. This implementation
* assumes that no backing-store files are needed: all required space
* can be obtained from malloc().
* This is very portable in the sense that it'll compile on almost anything,
* but you'd better have lots of main memory (or virtual memory) if you want
* to process big images.
* Note that the max_memory_to_use option is ignored by this implementation.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jmemsys.h" /* import the system-dependent declarations */
#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
extern void * malloc JPP((size_t size));
extern void free JPP((void *ptr));
#endif
/*
* Memory allocation and freeing are controlled by the regular library
* routines malloc() and free().
*/
GLOBAL(void *)
jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
{
return (void *) malloc(sizeofobject);
}
GLOBAL(void)
jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
{
free(object);
}
/*
* "Large" objects are treated the same as "small" ones.
* NB: although we include FAR keywords in the routine declarations,
* this file won't actually work in 80x86 small/medium model; at least,
* you probably won't be able to process useful-size images in only 64KB.
*/
GLOBAL(void FAR *)
jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
{
return (void FAR *) malloc(sizeofobject);
}
GLOBAL(void)
jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
{
free(object);
}
/*
* This routine computes the total memory space available for allocation.
* Here we always say, "we got all you want bud!"
*/
GLOBAL(long)
jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
long max_bytes_needed, long already_allocated)
{
return max_bytes_needed;
}
/*
* Backing store (temporary file) management.
* Since jpeg_mem_available always promised the moon,
* this should never be called and we can just error out.
*/
GLOBAL(void)
jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
long total_bytes_needed)
{
ERREXIT(cinfo, JERR_NO_BACKING_STORE);
}
/*
* These routines take care of any system-dependent initialization and
* cleanup required. Here, there isn't any.
*/
GLOBAL(long)
jpeg_mem_init (j_common_ptr cinfo)
{
return 0; /* just set max_memory_to_use to 0 */
}
GLOBAL(void)
jpeg_mem_term (j_common_ptr cinfo)
{
/* no work */
}
--- NEW FILE: jidctfst.c ---
/*
* jidctfst.c
*
* Copyright (C) 1994-1998, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains a fast, not so accurate integer implementation of the
* inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
* must also perform dequantization of the input coefficients.
*
* A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
* on each row (or vice versa, but it's more convenient to emit a row at
* a time). Direct algorithms are also available, but they are much more
* complex and seem not to be any faster when reduced to code.
*
* This implementation is based on Arai, Agui, and Nakajima's algorithm for
* scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
* Japanese, but the algorithm is described in the Pennebaker & Mitchell
* JPEG textbook (see REFERENCES section in file README). The following code
* is based directly on figure 4-8 in P&M.
* While an 8-point DCT cannot be done in less than 11 multiplies, it is
* possible to arrange the computation so that many of the multiplies are
* simple scalings of the final outputs. These multiplies can then be
* folded into the multiplications or divisions by the JPEG quantization
* table entries. The AA&N method leaves only 5 multiplies and 29 adds
* to be done in the DCT itself.
* The primary disadvantage of this method is that with fixed-point math,
* accuracy is lost due to imprecise representation of the scaled
* quantization values. The smaller the quantization table entry, the less
* precise the scaled value, so this implementation does worse with high-
* quality-setting files than with low-quality ones.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
#ifdef DCT_IFAST_SUPPORTED
/*
* This module is specialized to the case DCTSIZE = 8.
*/
#if DCTSIZE != 8
Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
#endif
/* Scaling decisions are generally the same as in the LL&M algorithm;
* see jidctint.c for more details. However, we choose to descale
* (right shift) multiplication products as soon as they are formed,
* rather than carrying additional fractional bits into subsequent additions.
* This compromises accuracy slightly, but it lets us save a few shifts.
* More importantly, 16-bit arithmetic is then adequate (for 8-bit samples)
* everywhere except in the multiplications proper; this saves a good deal
* of work on 16-bit-int machines.
*
* The dequantized coefficients are not integers because the AA&N scaling
* factors have been incorporated. We represent them scaled up by PASS1_BITS,
* so that the first and second IDCT rounds have the same input scaling.
* For 8-bit JSAMPLEs, we choose IFAST_SCALE_BITS = PASS1_BITS so as to
* avoid a descaling shift; this compromises accuracy rather drastically
* for small quantization table entries, but it saves a lot of shifts.
* For 12-bit JSAMPLEs, there's no hope of using 16x16 multiplies anyway,
* so we use a much larger scaling factor to preserve accuracy.
*
* A final compromise is to represent the multiplicative constants to only
* 8 fractional bits, rather than 13. This saves some shifting work on some
* machines, and may also reduce the cost of multiplication (since there
* are fewer one-bits in the constants).
*/
#if BITS_IN_JSAMPLE == 8
#define CONST_BITS 8
#define PASS1_BITS 2
#else
#define CONST_BITS 8
#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
#endif
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
* causing a lot of useless floating-point operations at run time.
* To get around this we use the following pre-calculated constants.
* If you change CONST_BITS you may want to add appropriate values.
* (With a reasonable C compiler, you can just rely on the FIX() macro...)
*/
#if CONST_BITS == 8
#define FIX_1_082392200 ((INT32) 277) /* FIX(1.082392200) */
#define FIX_1_414213562 ((INT32) 362) /* FIX(1.414213562) */
#define FIX_1_847759065 ((INT32) 473) /* FIX(1.847759065) */
#define FIX_2_613125930 ((INT32) 669) /* FIX(2.613125930) */
#else
#define FIX_1_082392200 FIX(1.082392200)
#define FIX_1_414213562 FIX(1.414213562)
#define FIX_1_847759065 FIX(1.847759065)
#define FIX_2_613125930 FIX(2.613125930)
#endif
/* We can gain a little more speed, with a further compromise in accuracy,
* by omitting the addition in a descaling shift. This yields an incorrectly
* rounded result half the time...
*/
#ifndef USE_ACCURATE_ROUNDING
#undef DESCALE
#define DESCALE(x,n) RIGHT_SHIFT(x, n)
#endif
/* Multiply a DCTELEM variable by an INT32 constant, and immediately
* descale to yield a DCTELEM result.
*/
#define MULTIPLY(var,const) ((DCTELEM) DESCALE((var) * (const), CONST_BITS))
/* Dequantize a coefficient by multiplying it by the multiplier-table
* entry; produce a DCTELEM result. For 8-bit data a 16x16->16
* multiplication will do. For 12-bit data, the multiplier table is
* declared INT32, so a 32-bit multiply will be used.
*/
#if BITS_IN_JSAMPLE == 8
#define DEQUANTIZE(coef,quantval) (((IFAST_MULT_TYPE) (coef)) * (quantval))
#else
#define DEQUANTIZE(coef,quantval) \
DESCALE((coef)*(quantval), IFAST_SCALE_BITS-PASS1_BITS)
#endif
/* Like DESCALE, but applies to a DCTELEM and produces an int.
* We assume that int right shift is unsigned if INT32 right shift is.
*/
#ifdef RIGHT_SHIFT_IS_UNSIGNED
#define ISHIFT_TEMPS DCTELEM ishift_temp;
#if BITS_IN_JSAMPLE == 8
#define DCTELEMBITS 16 /* DCTELEM may be 16 or 32 bits */
#else
#define DCTELEMBITS 32 /* DCTELEM must be 32 bits */
#endif
#define IRIGHT_SHIFT(x,shft) \
((ishift_temp = (x)) < 0 ? \
(ishift_temp >> (shft)) | ((~((DCTELEM) 0)) << (DCTELEMBITS-(shft))) : \
(ishift_temp >> (shft)))
#else
#define ISHIFT_TEMPS
#define IRIGHT_SHIFT(x,shft) ((x) >> (shft))
#endif
#ifdef USE_ACCURATE_ROUNDING
#define IDESCALE(x,n) ((int) IRIGHT_SHIFT((x) + (1 << ((n)-1)), n))
#else
#define IDESCALE(x,n) ((int) IRIGHT_SHIFT(x, n))
#endif
/*
* Perform dequantization and inverse DCT on one block of coefficients.
*/
GLOBAL(void)
jpeg_idct_ifast (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
DCTELEM tmp10, tmp11, tmp12, tmp13;
DCTELEM z5, z10, z11, z12, z13;
JCOEFPTR inptr;
IFAST_MULT_TYPE * quantptr;
int * wsptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[DCTSIZE2]; /* buffers data between passes */
SHIFT_TEMPS /* for DESCALE */
ISHIFT_TEMPS /* for IDESCALE */
/* Pass 1: process columns from input, store into work array. */
inptr = coef_block;
quantptr = (IFAST_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; ctr--) {
/* Due to quantization, we will usually find that many of the input
* coefficients are zero, especially the AC terms. We can exploit this
* by short-circuiting the IDCT calculation for any column in which all
* the AC terms are zero. In that case each output is equal to the
* DC coefficient (with scale factor as needed).
* With typical images and quantization tables, half or more of the
* column DCT calculations can be simplified this way.
*/
if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 &&
inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 &&
inptr[DCTSIZE*7] == 0) {
/* AC terms all zero */
int dcval = (int) DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
wsptr[DCTSIZE*0] = dcval;
wsptr[DCTSIZE*1] = dcval;
wsptr[DCTSIZE*2] = dcval;
wsptr[DCTSIZE*3] = dcval;
wsptr[DCTSIZE*4] = dcval;
wsptr[DCTSIZE*5] = dcval;
wsptr[DCTSIZE*6] = dcval;
wsptr[DCTSIZE*7] = dcval;
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
continue;
}
/* Even part */
tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
tmp10 = tmp0 + tmp2; /* phase 3 */
tmp11 = tmp0 - tmp2;
tmp13 = tmp1 + tmp3; /* phases 5-3 */
tmp12 = MULTIPLY(tmp1 - tmp3, FIX_1_414213562) - tmp13; /* 2*c4 */
tmp0 = tmp10 + tmp13; /* phase 2 */
tmp3 = tmp10 - tmp13;
tmp1 = tmp11 + tmp12;
tmp2 = tmp11 - tmp12;
/* Odd part */
tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
z13 = tmp6 + tmp5; /* phase 6 */
z10 = tmp6 - tmp5;
z11 = tmp4 + tmp7;
z12 = tmp4 - tmp7;
tmp7 = z11 + z13; /* phase 5 */
tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562); /* 2*c4 */
z5 = MULTIPLY(z10 + z12, FIX_1_847759065); /* 2*c2 */
tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5; /* 2*(c2-c6) */
tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5; /* -2*(c2+c6) */
tmp6 = tmp12 - tmp7; /* phase 2 */
tmp5 = tmp11 - tmp6;
tmp4 = tmp10 + tmp5;
wsptr[DCTSIZE*0] = (int) (tmp0 + tmp7);
wsptr[DCTSIZE*7] = (int) (tmp0 - tmp7);
wsptr[DCTSIZE*1] = (int) (tmp1 + tmp6);
wsptr[DCTSIZE*6] = (int) (tmp1 - tmp6);
wsptr[DCTSIZE*2] = (int) (tmp2 + tmp5);
wsptr[DCTSIZE*5] = (int) (tmp2 - tmp5);
wsptr[DCTSIZE*4] = (int) (tmp3 + tmp4);
wsptr[DCTSIZE*3] = (int) (tmp3 - tmp4);
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
}
/* Pass 2: process rows from work array, store into output array. */
/* Note that we must descale the results by a factor of 8 == 2**3, */
/* and also undo the PASS1_BITS scaling. */
wsptr = workspace;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Rows of zeroes can be exploited in the same way as we did with columns.
* However, the column calculation has created many nonzero AC terms, so
* the simplification applies less often (typically 5% to 10% of the time).
* On machines with very fast multiplication, it's possible that the
* test takes more time than it's worth. In that case this section
* may be commented out.
*/
#ifndef NO_ZERO_ROW_TEST
if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 &&
wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
/* AC terms all zero */
JSAMPLE dcval = range_limit[IDESCALE(wsptr[0], PASS1_BITS+3)
& RANGE_MASK];
outptr[0] = dcval;
outptr[1] = dcval;
outptr[2] = dcval;
outptr[3] = dcval;
outptr[4] = dcval;
outptr[5] = dcval;
outptr[6] = dcval;
outptr[7] = dcval;
wsptr += DCTSIZE; /* advance pointer to next row */
continue;
}
#endif
/* Even part */
tmp10 = ((DCTELEM) wsptr[0] + (DCTELEM) wsptr[4]);
tmp11 = ((DCTELEM) wsptr[0] - (DCTELEM) wsptr[4]);
tmp13 = ((DCTELEM) wsptr[2] + (DCTELEM) wsptr[6]);
tmp12 = MULTIPLY((DCTELEM) wsptr[2] - (DCTELEM) wsptr[6], FIX_1_414213562)
- tmp13;
tmp0 = tmp10 + tmp13;
tmp3 = tmp10 - tmp13;
tmp1 = tmp11 + tmp12;
tmp2 = tmp11 - tmp12;
/* Odd part */
z13 = (DCTELEM) wsptr[5] + (DCTELEM) wsptr[3];
z10 = (DCTELEM) wsptr[5] - (DCTELEM) wsptr[3];
z11 = (DCTELEM) wsptr[1] + (DCTELEM) wsptr[7];
z12 = (DCTELEM) wsptr[1] - (DCTELEM) wsptr[7];
tmp7 = z11 + z13; /* phase 5 */
tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562); /* 2*c4 */
z5 = MULTIPLY(z10 + z12, FIX_1_847759065); /* 2*c2 */
tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5; /* 2*(c2-c6) */
tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5; /* -2*(c2+c6) */
tmp6 = tmp12 - tmp7; /* phase 2 */
tmp5 = tmp11 - tmp6;
tmp4 = tmp10 + tmp5;
/* Final output stage: scale down by a factor of 8 and range-limit */
outptr[0] = range_limit[IDESCALE(tmp0 + tmp7, PASS1_BITS+3)
& RANGE_MASK];
outptr[7] = range_limit[IDESCALE(tmp0 - tmp7, PASS1_BITS+3)
& RANGE_MASK];
outptr[1] = range_limit[IDESCALE(tmp1 + tmp6, PASS1_BITS+3)
& RANGE_MASK];
outptr[6] = range_limit[IDESCALE(tmp1 - tmp6, PASS1_BITS+3)
& RANGE_MASK];
outptr[2] = range_limit[IDESCALE(tmp2 + tmp5, PASS1_BITS+3)
& RANGE_MASK];
outptr[5] = range_limit[IDESCALE(tmp2 - tmp5, PASS1_BITS+3)
& RANGE_MASK];
outptr[4] = range_limit[IDESCALE(tmp3 + tmp4, PASS1_BITS+3)
& RANGE_MASK];
outptr[3] = range_limit[IDESCALE(tmp3 - tmp4, PASS1_BITS+3)
& RANGE_MASK];
wsptr += DCTSIZE; /* advance pointer to next row */
}
}
#endif /* DCT_IFAST_SUPPORTED */
--- NEW FILE: jdatadst.c ---
/*
* jdatadst.c
*
* Copyright (C) 1994-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains compression data destination routines for the case of
* emitting JPEG data to a file (or any stdio stream). While these routines
* are sufficient for most applications, some will want to use a different
* destination manager.
* IMPORTANT: we assume that fwrite() will correctly transcribe an array of
* JOCTETs into 8-bit-wide elements on external storage. If char is wider
* than 8 bits on your machine, you may need to do some tweaking.
*/
/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
#include "jinclude.h"
#include "jpeglib.h"
#include "jerror.h"
/* Expanded data destination object for stdio output */
typedef struct {
struct jpeg_destination_mgr pub; /* public fields */
FILE * outfile; /* target stream */
JOCTET * buffer; /* start of buffer */
} my_destination_mgr;
typedef my_destination_mgr * my_dest_ptr;
#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
/*
* Initialize destination --- called by jpeg_start_compress
* before any data is actually written.
*/
METHODDEF(void)
init_destination (j_compress_ptr cinfo)
{
my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
/* Allocate the output buffer --- it will be released when done with image */
dest->buffer = (JOCTET *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
OUTPUT_BUF_SIZE * SIZEOF(JOCTET));
dest->pub.next_output_byte = dest->buffer;
dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
}
/*
* Empty the output buffer --- called whenever buffer fills up.
*
* In typical applications, this should write the entire output buffer
* (ignoring the current state of next_output_byte & free_in_buffer),
* reset the pointer & count to the start of the buffer, and return TRUE
* indicating that the buffer has been dumped.
*
* In applications that need to be able to suspend compression due to output
* overrun, a FALSE return indicates that the buffer cannot be emptied now.
* In this situation, the compressor will return to its caller (possibly with
* an indication that it has not accepted all the supplied scanlines). The
* application should resume compression after it has made more room in the
* output buffer. Note that there are substantial restrictions on the use of
* suspension --- see the documentation.
*
* When suspending, the compressor will back up to a convenient restart point
* (typically the start of the current MCU). next_output_byte & free_in_buffer
* indicate where the restart point will be if the current call returns FALSE.
* Data beyond this point will be regenerated after resumption, so do not
* write it out when emptying the buffer externally.
*/
METHODDEF(boolean)
empty_output_buffer (j_compress_ptr cinfo)
{
my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
if (JFWRITE(dest->outfile, dest->buffer, OUTPUT_BUF_SIZE) !=
(size_t) OUTPUT_BUF_SIZE)
ERREXIT(cinfo, JERR_FILE_WRITE);
dest->pub.next_output_byte = dest->buffer;
dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
return TRUE;
}
/*
* Terminate destination --- called by jpeg_finish_compress
* after all data has been written. Usually needs to flush buffer.
*
* NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
* application must deal with any cleanup that should happen even
* for error exit.
*/
METHODDEF(void)
term_destination (j_compress_ptr cinfo)
{
my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
/* Write any data remaining in the buffer */
if (datacount > 0) {
if (JFWRITE(dest->outfile, dest->buffer, datacount) != datacount)
ERREXIT(cinfo, JERR_FILE_WRITE);
}
fflush(dest->outfile);
/* Make sure we wrote the output file OK */
if (ferror(dest->outfile))
ERREXIT(cinfo, JERR_FILE_WRITE);
}
/*
* Prepare for output to a stdio stream.
* The caller must have already opened the stream, and is responsible
* for closing it after finishing compression.
*/
GLOBAL(void)
jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile)
{
my_dest_ptr dest;
/* The destination object is made permanent so that multiple JPEG images
* can be written to the same file without re-executing jpeg_stdio_dest.
* This makes it dangerous to use this manager and a different destination
* manager serially with the same JPEG object, because their private object
* sizes may be different. Caveat programmer.
*/
if (cinfo->dest == NULL) { /* first time for this JPEG object? */
cinfo->dest = (struct jpeg_destination_mgr *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
SIZEOF(my_destination_mgr));
}
dest = (my_dest_ptr) cinfo->dest;
dest->pub.init_destination = init_destination;
dest->pub.empty_output_buffer = empty_output_buffer;
dest->pub.term_destination = term_destination;
dest->outfile = outfile;
}
--- NEW FILE: jdsample.c ---
/*
* jdsample.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains upsampling routines.
*
* Upsampling input data is counted in "row groups". A row group
* is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
* sample rows of each component. Upsampling will normally produce
* max_v_samp_factor pixel rows from each row group (but this could vary
* if the upsampler is applying a scale factor of its own).
*
* An excellent reference for image resampling is
* Digital Image Warping, George Wolberg, 1990.
* Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
/* Pointer to routine to upsample a single component */
typedef JMETHOD(void, upsample1_ptr,
(j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr));
/* Private subobject */
typedef struct {
struct jpeg_upsampler pub; /* public fields */
/* Color conversion buffer. When using separate upsampling and color
* conversion steps, this buffer holds one upsampled row group until it
* has been color converted and output.
* Note: we do not allocate any storage for component(s) which are full-size,
* ie do not need rescaling. The corresponding entry of color_buf[] is
* simply set to point to the input data array, thereby avoiding copying.
*/
JSAMPARRAY color_buf[MAX_COMPONENTS];
/* Per-component upsampling method pointers */
upsample1_ptr methods[MAX_COMPONENTS];
int next_row_out; /* counts rows emitted from color_buf */
JDIMENSION rows_to_go; /* counts rows remaining in image */
/* Height of an input row group for each component. */
int rowgroup_height[MAX_COMPONENTS];
/* These arrays save pixel expansion factors so that int_expand need not
* recompute them each time. They are unused for other upsampling methods.
*/
UINT8 h_expand[MAX_COMPONENTS];
UINT8 v_expand[MAX_COMPONENTS];
} my_upsampler;
typedef my_upsampler * my_upsample_ptr;
/*
* Initialize for an upsampling pass.
*/
METHODDEF(void)
start_pass_upsample (j_decompress_ptr cinfo)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
/* Mark the conversion buffer empty */
upsample->next_row_out = cinfo->max_v_samp_factor;
/* Initialize total-height counter for detecting bottom of image */
upsample->rows_to_go = cinfo->output_height;
}
/*
* Control routine to do upsampling (and color conversion).
*
* In this version we upsample each component independently.
* We upsample one row group into the conversion buffer, then apply
* color conversion a row at a time.
*/
METHODDEF(void)
sep_upsample (j_decompress_ptr cinfo,
JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
JDIMENSION in_row_groups_avail,
JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
JDIMENSION out_rows_avail)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
int ci;
jpeg_component_info * compptr;
JDIMENSION num_rows;
/* Fill the conversion buffer, if it's empty */
if (upsample->next_row_out >= cinfo->max_v_samp_factor) {
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Invoke per-component upsample method. Notice we pass a POINTER
* to color_buf[ci], so that fullsize_upsample can change it.
*/
(*upsample->methods[ci]) (cinfo, compptr,
input_buf[ci] + (*in_row_group_ctr * upsample->rowgroup_height[ci]),
upsample->color_buf + ci);
}
upsample->next_row_out = 0;
}
/* Color-convert and emit rows */
/* How many we have in the buffer: */
num_rows = (JDIMENSION) (cinfo->max_v_samp_factor - upsample->next_row_out);
/* Not more than the distance to the end of the image. Need this test
* in case the image height is not a multiple of max_v_samp_factor:
*/
if (num_rows > upsample->rows_to_go)
num_rows = upsample->rows_to_go;
/* And not more than what the client can accept: */
out_rows_avail -= *out_row_ctr;
if (num_rows > out_rows_avail)
num_rows = out_rows_avail;
(*cinfo->cconvert->color_convert) (cinfo, upsample->color_buf,
(JDIMENSION) upsample->next_row_out,
output_buf + *out_row_ctr,
(int) num_rows);
/* Adjust counts */
*out_row_ctr += num_rows;
upsample->rows_to_go -= num_rows;
upsample->next_row_out += num_rows;
/* When the buffer is emptied, declare this input row group consumed */
if (upsample->next_row_out >= cinfo->max_v_samp_factor)
(*in_row_group_ctr)++;
}
/*
* These are the routines invoked by sep_upsample to upsample pixel values
* of a single component. One row group is processed per call.
*/
/*
* For full-size components, we just make color_buf[ci] point at the
* input buffer, and thus avoid copying any data. Note that this is
* safe only because sep_upsample doesn't declare the input row group
* "consumed" until we are done color converting and emitting it.
*/
METHODDEF(void)
fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
*output_data_ptr = input_data;
}
/*
* This is a no-op version used for "uninteresting" components.
* These components will not be referenced by color conversion.
*/
METHODDEF(void)
noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
*output_data_ptr = NULL; /* safety check */
}
/*
* This version handles any integral sampling ratios.
* This is not used for typical JPEG files, so it need not be fast.
* Nor, for that matter, is it particularly accurate: the algorithm is
* simple replication of the input pixel onto the corresponding output
* pixels. The hi-falutin sampling literature refers to this as a
* "box filter". A box filter tends to introduce visible artifacts,
* so if you are actually going to use 3:1 or 4:1 sampling ratios
* you would be well advised to improve this code.
*/
METHODDEF(void)
int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
JSAMPARRAY output_data = *output_data_ptr;
register JSAMPROW inptr, outptr;
register JSAMPLE invalue;
register int h;
JSAMPROW outend;
int h_expand, v_expand;
int inrow, outrow;
h_expand = upsample->h_expand[compptr->component_index];
v_expand = upsample->v_expand[compptr->component_index];
inrow = outrow = 0;
while (outrow < cinfo->max_v_samp_factor) {
/* Generate one output row with proper horizontal expansion */
inptr = input_data[inrow];
outptr = output_data[outrow];
outend = outptr + cinfo->output_width;
while (outptr < outend) {
invalue = *inptr++; /* don't need GETJSAMPLE() here */
for (h = h_expand; h > 0; h--) {
*outptr++ = invalue;
}
}
/* Generate any additional output rows by duplicating the first one */
if (v_expand > 1) {
jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
v_expand-1, cinfo->output_width);
}
inrow++;
outrow += v_expand;
}
}
/*
* Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
* It's still a box filter.
*/
METHODDEF(void)
h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
JSAMPARRAY output_data = *output_data_ptr;
register JSAMPROW inptr, outptr;
register JSAMPLE invalue;
JSAMPROW outend;
int inrow;
for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
inptr = input_data[inrow];
outptr = output_data[inrow];
outend = outptr + cinfo->output_width;
while (outptr < outend) {
invalue = *inptr++; /* don't need GETJSAMPLE() here */
*outptr++ = invalue;
*outptr++ = invalue;
}
}
}
/*
* Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
* It's still a box filter.
*/
METHODDEF(void)
h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
JSAMPARRAY output_data = *output_data_ptr;
register JSAMPROW inptr, outptr;
register JSAMPLE invalue;
JSAMPROW outend;
int inrow, outrow;
inrow = outrow = 0;
while (outrow < cinfo->max_v_samp_factor) {
inptr = input_data[inrow];
outptr = output_data[outrow];
outend = outptr + cinfo->output_width;
while (outptr < outend) {
invalue = *inptr++; /* don't need GETJSAMPLE() here */
*outptr++ = invalue;
*outptr++ = invalue;
}
jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
1, cinfo->output_width);
inrow++;
outrow += 2;
}
}
/*
* Fancy processing for the common case of 2:1 horizontal and 1:1 vertical.
*
* The upsampling algorithm is linear interpolation between pixel centers,
* also known as a "triangle filter". This is a good compromise between
* speed and visual quality. The centers of the output pixels are 1/4 and 3/4
* of the way between input pixel centers.
*
* A note about the "bias" calculations: when rounding fractional values to
* integer, we do not want to always round 0.5 up to the next integer.
* If we did that, we'd introduce a noticeable bias towards larger values.
* Instead, this code is arranged so that 0.5 will be rounded up or down at
* alternate pixel locations (a simple ordered dither pattern).
*/
METHODDEF(void)
h2v1_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
JSAMPARRAY output_data = *output_data_ptr;
register JSAMPROW inptr, outptr;
register int invalue;
register JDIMENSION colctr;
int inrow;
for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
inptr = input_data[inrow];
outptr = output_data[inrow];
/* Special case for first column */
invalue = GETJSAMPLE(*inptr++);
*outptr++ = (JSAMPLE) invalue;
*outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(*inptr) + 2) >> 2);
for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) {
/* General case: 3/4 * nearer pixel + 1/4 * further pixel */
invalue = GETJSAMPLE(*inptr++) * 3;
*outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(inptr[-2]) + 1) >> 2);
*outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(*inptr) + 2) >> 2);
}
/* Special case for last column */
invalue = GETJSAMPLE(*inptr);
*outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(inptr[-1]) + 1) >> 2);
*outptr++ = (JSAMPLE) invalue;
}
}
/*
* Fancy processing for the common case of 2:1 horizontal and 2:1 vertical.
* Again a triangle filter; see comments for h2v1 case, above.
*
* It is OK for us to reference the adjacent input rows because we demanded
* context from the main buffer controller (see initialization code).
*/
METHODDEF(void)
h2v2_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
{
JSAMPARRAY output_data = *output_data_ptr;
register JSAMPROW inptr0, inptr1, outptr;
#if BITS_IN_JSAMPLE == 8
register int thiscolsum, lastcolsum, nextcolsum;
#else
register INT32 thiscolsum, lastcolsum, nextcolsum;
#endif
register JDIMENSION colctr;
int inrow, outrow, v;
inrow = outrow = 0;
while (outrow < cinfo->max_v_samp_factor) {
for (v = 0; v < 2; v++) {
/* inptr0 points to nearest input row, inptr1 points to next nearest */
inptr0 = input_data[inrow];
if (v == 0) /* next nearest is row above */
inptr1 = input_data[inrow-1];
else /* next nearest is row below */
inptr1 = input_data[inrow+1];
outptr = output_data[outrow++];
/* Special case for first column */
thiscolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
*outptr++ = (JSAMPLE) ((thiscolsum * 4 + 8) >> 4);
*outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4);
lastcolsum = thiscolsum; thiscolsum = nextcolsum;
for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) {
/* General case: 3/4 * nearer pixel + 1/4 * further pixel in each */
/* dimension, thus 9/16, 3/16, 3/16, 1/16 overall */
nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
*outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4);
*outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4);
lastcolsum = thiscolsum; thiscolsum = nextcolsum;
}
/* Special case for last column */
*outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4);
*outptr++ = (JSAMPLE) ((thiscolsum * 4 + 7) >> 4);
}
inrow++;
}
}
/*
* Module initialization routine for upsampling.
*/
GLOBAL(void)
jinit_upsampler (j_decompress_ptr cinfo)
{
my_upsample_ptr upsample;
int ci;
jpeg_component_info * compptr;
boolean need_buffer, do_fancy;
int h_in_group, v_in_group, h_out_group, v_out_group;
upsample = (my_upsample_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_upsampler));
cinfo->upsample = (struct jpeg_upsampler *) upsample;
upsample->pub.start_pass = start_pass_upsample;
upsample->pub.upsample = sep_upsample;
upsample->pub.need_context_rows = FALSE; /* until we find out differently */
if (cinfo->CCIR601_sampling) /* this isn't supported */
ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
/* jdmainct.c doesn't support context rows when min_DCT_scaled_size = 1,
* so don't ask for it.
*/
do_fancy = cinfo->do_fancy_upsampling && cinfo->min_DCT_scaled_size > 1;
/* Verify we can handle the sampling factors, select per-component methods,
* and create storage as needed.
*/
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
/* Compute size of an "input group" after IDCT scaling. This many samples
* are to be converted to max_h_samp_factor * max_v_samp_factor pixels.
*/
h_in_group = (compptr->h_samp_factor * compptr->DCT_scaled_size) /
cinfo->min_DCT_scaled_size;
v_in_group = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
cinfo->min_DCT_scaled_size;
h_out_group = cinfo->max_h_samp_factor;
v_out_group = cinfo->max_v_samp_factor;
upsample->rowgroup_height[ci] = v_in_group; /* save for use later */
need_buffer = TRUE;
if (! compptr->component_needed) {
/* Don't bother to upsample an uninteresting component. */
upsample->methods[ci] = noop_upsample;
need_buffer = FALSE;
} else if (h_in_group == h_out_group && v_in_group == v_out_group) {
/* Fullsize components can be processed without any work. */
upsample->methods[ci] = fullsize_upsample;
need_buffer = FALSE;
} else if (h_in_group * 2 == h_out_group &&
v_in_group == v_out_group) {
/* Special cases for 2h1v upsampling */
if (do_fancy && compptr->downsampled_width > 2)
upsample->methods[ci] = h2v1_fancy_upsample;
else
upsample->methods[ci] = h2v1_upsample;
} else if (h_in_group * 2 == h_out_group &&
v_in_group * 2 == v_out_group) {
/* Special cases for 2h2v upsampling */
if (do_fancy && compptr->downsampled_width > 2) {
upsample->methods[ci] = h2v2_fancy_upsample;
upsample->pub.need_context_rows = TRUE;
} else
upsample->methods[ci] = h2v2_upsample;
} else if ((h_out_group % h_in_group) == 0 &&
(v_out_group % v_in_group) == 0) {
/* Generic integral-factors upsampling method */
upsample->methods[ci] = int_upsample;
upsample->h_expand[ci] = (UINT8) (h_out_group / h_in_group);
upsample->v_expand[ci] = (UINT8) (v_out_group / v_in_group);
} else
ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
if (need_buffer) {
upsample->color_buf[ci] = (*cinfo->mem->alloc_sarray)
((j_common_ptr) cinfo, JPOOL_IMAGE,
(JDIMENSION) jround_up((long) cinfo->output_width,
(long) cinfo->max_h_samp_factor),
(JDIMENSION) cinfo->max_v_samp_factor);
}
}
}
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