/*
* jdmaster.c
*
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1997, Thomas G. Lane.
* Modified 2002-2009 by Guido Vollbeding.
* libjpeg-turbo Modifications:
* Copyright (C) 2009-2011, 2016, D. R. Commander.
* Copyright (C) 2013, Linaro Limited.
* Copyright (C) 2015, Google, Inc.
* For conditions of distribution and use, see the accompanying README.ijg
* 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"
#include "jpegcomp.h"
#include "jdmaster.h"
#include "jsimd.h"
/*
* 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 and YCC=>RGB565 color conversion */
if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 ||
(cinfo->out_color_space != JCS_RGB &&
cinfo->out_color_space != JCS_RGB565 &&
cinfo->out_color_space != JCS_EXT_RGB &&
cinfo->out_color_space != JCS_EXT_RGBX &&
cinfo->out_color_space != JCS_EXT_BGR &&
cinfo->out_color_space != JCS_EXT_BGRX &&
cinfo->out_color_space != JCS_EXT_XBGR &&
cinfo->out_color_space != JCS_EXT_XRGB &&
cinfo->out_color_space != JCS_EXT_RGBA &&
cinfo->out_color_space != JCS_EXT_BGRA &&
cinfo->out_color_space != JCS_EXT_ABGR &&
cinfo->out_color_space != JCS_EXT_ARGB))
return FALSE;
if ((cinfo->out_color_space == JCS_RGB565 &&
cinfo->out_color_components != 3) ||
(cinfo->out_color_space != JCS_RGB565 &&
cinfo->out_color_components != rgb_pixelsize[cinfo->out_color_space]))
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;
#ifdef WITH_SIMD
/* If YCbCr-to-RGB color conversion is SIMD-accelerated but merged upsampling
isn't, then disabling merged upsampling is likely to be faster when
decompressing YCbCr JPEG images. */
if (!jsimd_can_h2v2_merged_upsample() && !jsimd_can_h2v1_merged_upsample() &&
jsimd_can_ycc_rgb() && cinfo->jpeg_color_space == JCS_YCbCr &&
(cinfo->out_color_space == JCS_RGB ||
(cinfo->out_color_space >= JCS_EXT_RGB &&
cinfo->out_color_space <= JCS_EXT_ARGB)))
return FALSE;
#endif
/* ??? 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.
*/
#if JPEG_LIB_VERSION >= 80
GLOBAL(void)
#else
LOCAL(void)
#endif
jpeg_core_output_dimensions(j_decompress_ptr cinfo)
/* Do computations that are needed before master selection phase.
* This function is used for transcoding and full decompression.
*/
{
#ifdef IDCT_SCALING_SUPPORTED
int ci;
jpeg_component_info *compptr;
/* Compute actual output image dimensions and DCT scaling choices. */
if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom) {
/* Provide 1/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 1;
cinfo->_min_DCT_v_scaled_size = 1;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 2) {
/* Provide 2/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 2L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 2L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 2;
cinfo->_min_DCT_v_scaled_size = 2;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 3) {
/* Provide 3/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 3L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 3L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 3;
cinfo->_min_DCT_v_scaled_size = 3;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 4) {
/* Provide 4/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 4L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 4L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 4;
cinfo->_min_DCT_v_scaled_size = 4;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 5) {
/* Provide 5/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 5L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 5L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 5;
cinfo->_min_DCT_v_scaled_size = 5;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 6) {
/* Provide 6/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 6L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 6L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 6;
cinfo->_min_DCT_v_scaled_size = 6;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 7) {
/* Provide 7/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 7L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 7L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 7;
cinfo->_min_DCT_v_scaled_size = 7;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 8) {
/* Provide 8/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 8L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 8L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 8;
cinfo->_min_DCT_v_scaled_size = 8;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 9) {
/* Provide 9/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 9L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 9L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 9;
cinfo->_min_DCT_v_scaled_size = 9;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 10) {
/* Provide 10/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 10L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 10L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 10;
cinfo->_min_DCT_v_scaled_size = 10;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 11) {
/* Provide 11/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 11L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 11L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 11;
cinfo->_min_DCT_v_scaled_size = 11;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 12) {
/* Provide 12/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 12L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 12L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 12;
cinfo->_min_DCT_v_scaled_size = 12;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 13) {
/* Provide 13/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 13L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 13L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 13;
cinfo->_min_DCT_v_scaled_size = 13;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 14) {
/* Provide 14/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 14L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 14L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 14;
cinfo->_min_DCT_v_scaled_size = 14;
} else if (cinfo->scale_num * DCTSIZE <= cinfo->scale_denom * 15) {
/* Provide 15/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 15L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 15L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 15;
cinfo->_min_DCT_v_scaled_size = 15;
} else {
/* Provide 16/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long)cinfo->image_width * 16L, (long)DCTSIZE);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long)cinfo->image_height * 16L, (long)DCTSIZE);
cinfo->_min_DCT_h_scaled_size = 16;
cinfo->_min_DCT_v_scaled_size = 16;
}
/* Recompute dimensions of components */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
compptr->_DCT_h_scaled_size = cinfo->_min_DCT_h_scaled_size;
compptr->_DCT_v_scaled_size = cinfo->_min_DCT_v_scaled_size;
}
#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,
* and has computed unscaled downsampled_width and downsampled_height.
*/
#endif /* IDCT_SCALING_SUPPORTED */
}
/*
* 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);
/* Compute core output image dimensions and DCT scaling choices. */
jpeg_core_output_dimensions(cinfo);
#ifdef IDCT_SCALING_SUPPORTED
/* 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 adapts subsampling ratios which 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 &&
((cinfo->max_h_samp_factor * cinfo->_min_DCT_scaled_size) %
(compptr->h_samp_factor * ssize * 2) == 0) &&
((cinfo->max_v_samp_factor * cinfo->_min_DCT_scaled_size) %
(compptr->v_samp_factor * ssize * 2) == 0)) {
ssize = ssize * 2;
}
#if JPEG_LIB_VERSION >= 70
compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = ssize;
#else
compptr->DCT_scaled_size = ssize;
#endif
}
/* 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:
case JCS_EXT_RGB:
case JCS_EXT_RGBX:
case JCS_EXT_BGR:
case JCS_EXT_BGRX:
case JCS_EXT_XBGR:
case JCS_EXT_XRGB:
case JCS_EXT_RGBA:
case JCS_EXT_BGRA:
case JCS_EXT_ABGR:
case JCS_EXT_ARGB:
cinfo->out_color_components = rgb_pixelsize[cinfo->out_color_space];
break;
case JCS_YCbCr:
case JCS_RGB565:
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.
*/
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) {
#ifdef D_ARITH_CODING_SUPPORTED
jinit_arith_decoder(cinfo);
#else
ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
#endif
} 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);
/* Set the first and last iMCU columns to decompress from single-scan images.
* By default, decompress all of the iMCU columns.
*/
cinfo->master->first_iMCU_col = 0;
cinfo->master->last_iMCU_col = cinfo->MCUs_per_row - 1;
#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 = (my_master_ptr)cinfo->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->pub.jinit_upsampler_no_alloc = FALSE;
master_selection(cinfo);
}