mirror of
git://source.winehq.org/git/wine.git
synced 2024-09-01 20:03:38 +00:00
592 lines
20 KiB
C
592 lines
20 KiB
C
/*
|
|
* jcparam.c
|
|
*
|
|
* Copyright (C) 1991-1998, Thomas G. Lane.
|
|
* Modified 2003-2022 by Guido Vollbeding.
|
|
* 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 optional default-setting code for the JPEG compressor.
|
|
* Applications do not have to use this file, but those that don't use it
|
|
* must know a lot more about the innards of the JPEG code.
|
|
*/
|
|
|
|
#define JPEG_INTERNALS
|
|
#include "jinclude.h"
|
|
#include "jpeglib.h"
|
|
|
|
|
|
/*
|
|
* Quantization table setup routines
|
|
*/
|
|
|
|
GLOBAL(void)
|
|
jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,
|
|
const unsigned int *basic_table,
|
|
int scale_factor, boolean force_baseline)
|
|
/* Define a quantization table equal to the basic_table times
|
|
* a scale factor (given as a percentage).
|
|
* If force_baseline is TRUE, the computed quantization table entries
|
|
* are limited to 1..255 for JPEG baseline compatibility.
|
|
*/
|
|
{
|
|
JQUANT_TBL ** qtblptr;
|
|
int i;
|
|
long temp;
|
|
|
|
/* Safety check to ensure start_compress not called yet. */
|
|
if (cinfo->global_state != CSTATE_START)
|
|
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
|
|
|
|
if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS)
|
|
ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl);
|
|
|
|
qtblptr = & cinfo->quant_tbl_ptrs[which_tbl];
|
|
|
|
if (*qtblptr == NULL)
|
|
*qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo);
|
|
|
|
for (i = 0; i < DCTSIZE2; i++) {
|
|
temp = ((long) basic_table[i] * scale_factor + 50L) / 100L;
|
|
/* limit the values to the valid range */
|
|
if (temp <= 0L) temp = 1L;
|
|
if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */
|
|
if (force_baseline && temp > 255L)
|
|
temp = 255L; /* limit to baseline range if requested */
|
|
(*qtblptr)->quantval[i] = (UINT16) temp;
|
|
}
|
|
|
|
/* Initialize sent_table FALSE so table will be written to JPEG file. */
|
|
(*qtblptr)->sent_table = FALSE;
|
|
}
|
|
|
|
|
|
/* These are the sample quantization tables given in JPEG spec section K.1.
|
|
* NOTE: chrominance DC value is changed from 17 to 16 for lossless support.
|
|
* The spec says that the values given produce "good" quality,
|
|
* and when divided by 2, "very good" quality.
|
|
*/
|
|
static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
|
|
16, 11, 10, 16, 24, 40, 51, 61,
|
|
12, 12, 14, 19, 26, 58, 60, 55,
|
|
14, 13, 16, 24, 40, 57, 69, 56,
|
|
14, 17, 22, 29, 51, 87, 80, 62,
|
|
18, 22, 37, 56, 68, 109, 103, 77,
|
|
24, 35, 55, 64, 81, 104, 113, 92,
|
|
49, 64, 78, 87, 103, 121, 120, 101,
|
|
72, 92, 95, 98, 112, 100, 103, 99
|
|
};
|
|
static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
|
|
16, 18, 24, 47, 99, 99, 99, 99,
|
|
18, 21, 26, 66, 99, 99, 99, 99,
|
|
24, 26, 56, 99, 99, 99, 99, 99,
|
|
47, 66, 99, 99, 99, 99, 99, 99,
|
|
99, 99, 99, 99, 99, 99, 99, 99,
|
|
99, 99, 99, 99, 99, 99, 99, 99,
|
|
99, 99, 99, 99, 99, 99, 99, 99,
|
|
99, 99, 99, 99, 99, 99, 99, 99
|
|
};
|
|
|
|
|
|
GLOBAL(void)
|
|
jpeg_default_qtables (j_compress_ptr cinfo, boolean force_baseline)
|
|
/* Set or change the 'quality' (quantization) setting, using default tables
|
|
* and straight percentage-scaling quality scales.
|
|
* This entry point allows different scalings for luminance and chrominance.
|
|
*/
|
|
{
|
|
/* Set up two quantization tables using the specified scaling */
|
|
jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
|
|
cinfo->q_scale_factor[0], force_baseline);
|
|
jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
|
|
cinfo->q_scale_factor[1], force_baseline);
|
|
}
|
|
|
|
|
|
GLOBAL(void)
|
|
jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor,
|
|
boolean force_baseline)
|
|
/* Set or change the 'quality' (quantization) setting, using default tables
|
|
* and a straight percentage-scaling quality scale. In most cases it's better
|
|
* to use jpeg_set_quality (below); this entry point is provided for
|
|
* applications that insist on a linear percentage scaling.
|
|
*/
|
|
{
|
|
/* Set up two quantization tables using the specified scaling */
|
|
jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
|
|
scale_factor, force_baseline);
|
|
jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
|
|
scale_factor, force_baseline);
|
|
}
|
|
|
|
|
|
GLOBAL(int)
|
|
jpeg_quality_scaling (int quality)
|
|
/* Convert a user-specified quality rating to a percentage scaling factor
|
|
* for an underlying quantization table, using our recommended scaling curve.
|
|
* The input 'quality' factor should be 0 (terrible) to 100 (very good).
|
|
*/
|
|
{
|
|
/* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */
|
|
if (quality <= 0) quality = 1;
|
|
if (quality > 100) quality = 100;
|
|
|
|
/* The basic table is used as-is (scaling 100) for a quality of 50.
|
|
* Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
|
|
* note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table
|
|
* to make all the table entries 1 (hence, minimum quantization loss).
|
|
* Qualities 1..50 are converted to scaling percentage 5000/Q.
|
|
*/
|
|
if (quality < 50)
|
|
quality = 5000 / quality;
|
|
else
|
|
quality = 200 - quality*2;
|
|
|
|
return quality;
|
|
}
|
|
|
|
|
|
GLOBAL(void)
|
|
jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline)
|
|
/* Set or change the 'quality' (quantization) setting, using default tables.
|
|
* This is the standard quality-adjusting entry point for typical user
|
|
* interfaces; only those who want detailed control over quantization tables
|
|
* would use the preceding routines directly.
|
|
*/
|
|
{
|
|
/* Convert user 0-100 rating to percentage scaling */
|
|
quality = jpeg_quality_scaling(quality);
|
|
|
|
/* Set up standard quality tables */
|
|
jpeg_set_linear_quality(cinfo, quality, force_baseline);
|
|
}
|
|
|
|
|
|
/*
|
|
* Reset standard Huffman tables
|
|
*/
|
|
|
|
LOCAL(void)
|
|
std_huff_tables (j_compress_ptr cinfo)
|
|
{
|
|
if (cinfo->dc_huff_tbl_ptrs[0] != NULL)
|
|
(void) jpeg_std_huff_table((j_common_ptr) cinfo, TRUE, 0);
|
|
|
|
if (cinfo->ac_huff_tbl_ptrs[0] != NULL)
|
|
(void) jpeg_std_huff_table((j_common_ptr) cinfo, FALSE, 0);
|
|
|
|
if (cinfo->dc_huff_tbl_ptrs[1] != NULL)
|
|
(void) jpeg_std_huff_table((j_common_ptr) cinfo, TRUE, 1);
|
|
|
|
if (cinfo->ac_huff_tbl_ptrs[1] != NULL)
|
|
(void) jpeg_std_huff_table((j_common_ptr) cinfo, FALSE, 1);
|
|
}
|
|
|
|
|
|
/*
|
|
* Default parameter setup for compression.
|
|
*
|
|
* Applications that don't choose to use this routine must do their
|
|
* own setup of all these parameters. Alternately, you can call this
|
|
* to establish defaults and then alter parameters selectively. This
|
|
* is the recommended approach since, if we add any new parameters,
|
|
* your code will still work (they'll be set to reasonable defaults).
|
|
*/
|
|
|
|
GLOBAL(void)
|
|
jpeg_set_defaults (j_compress_ptr cinfo)
|
|
{
|
|
int i;
|
|
|
|
/* Safety check to ensure start_compress not called yet. */
|
|
if (cinfo->global_state != CSTATE_START)
|
|
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
|
|
|
|
/* Allocate comp_info array large enough for maximum component count.
|
|
* Array is made permanent in case application wants to compress
|
|
* multiple images at same param settings.
|
|
*/
|
|
if (cinfo->comp_info == NULL)
|
|
cinfo->comp_info = (jpeg_component_info *)
|
|
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
|
|
MAX_COMPONENTS * SIZEOF(jpeg_component_info));
|
|
|
|
/* Initialize everything not dependent on the color space */
|
|
|
|
cinfo->scale_num = 1; /* 1:1 scaling */
|
|
cinfo->scale_denom = 1;
|
|
cinfo->data_precision = BITS_IN_JSAMPLE;
|
|
/* Set up two quantization tables using default quality of 75 */
|
|
jpeg_set_quality(cinfo, 75, TRUE);
|
|
/* Reset standard Huffman tables */
|
|
std_huff_tables(cinfo);
|
|
|
|
/* Initialize default arithmetic coding conditioning */
|
|
for (i = 0; i < NUM_ARITH_TBLS; i++) {
|
|
cinfo->arith_dc_L[i] = 0;
|
|
cinfo->arith_dc_U[i] = 1;
|
|
cinfo->arith_ac_K[i] = 5;
|
|
}
|
|
|
|
/* Default is no multiple-scan output */
|
|
cinfo->scan_info = NULL;
|
|
cinfo->num_scans = 0;
|
|
|
|
/* Expect normal source image, not raw downsampled data */
|
|
cinfo->raw_data_in = FALSE;
|
|
|
|
/* The standard Huffman tables are only valid for 8-bit data precision.
|
|
* If the precision is higher, use arithmetic coding.
|
|
* (Alternatively, using Huffman coding would be possible with forcing
|
|
* optimization on so that usable tables will be computed, or by
|
|
* supplying default tables that are valid for the desired precision.)
|
|
* Otherwise, use Huffman coding by default.
|
|
*/
|
|
cinfo->arith_code = cinfo->data_precision > 8 ? TRUE : FALSE;
|
|
|
|
/* By default, don't do extra passes to optimize entropy coding */
|
|
cinfo->optimize_coding = FALSE;
|
|
|
|
/* By default, use the simpler non-cosited sampling alignment */
|
|
cinfo->CCIR601_sampling = FALSE;
|
|
|
|
/* By default, apply fancy downsampling */
|
|
cinfo->do_fancy_downsampling = TRUE;
|
|
|
|
/* No input smoothing */
|
|
cinfo->smoothing_factor = 0;
|
|
|
|
/* DCT algorithm preference */
|
|
cinfo->dct_method = JDCT_DEFAULT;
|
|
|
|
/* No restart markers */
|
|
cinfo->restart_interval = 0;
|
|
cinfo->restart_in_rows = 0;
|
|
|
|
/* Fill in default JFIF marker parameters. Note that whether the marker
|
|
* will actually be written is determined by jpeg_set_colorspace.
|
|
*
|
|
* By default, the library emits JFIF version code 1.01.
|
|
* An application that wants to emit JFIF 1.02 extension markers should set
|
|
* JFIF_minor_version to 2. We could probably get away with just defaulting
|
|
* to 1.02, but there may still be some decoders in use that will complain
|
|
* about that; saying 1.01 should minimize compatibility problems.
|
|
*
|
|
* For wide gamut colorspaces (BG_RGB and BG_YCC), the major version will be
|
|
* overridden by jpeg_set_colorspace and set to 2.
|
|
*/
|
|
cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */
|
|
cinfo->JFIF_minor_version = 1;
|
|
cinfo->density_unit = 0; /* Pixel size is unknown by default */
|
|
cinfo->X_density = 1; /* Pixel aspect ratio is square by default */
|
|
cinfo->Y_density = 1;
|
|
|
|
/* No color transform */
|
|
cinfo->color_transform = JCT_NONE;
|
|
|
|
/* Choose JPEG colorspace based on input space, set defaults accordingly */
|
|
|
|
jpeg_default_colorspace(cinfo);
|
|
}
|
|
|
|
|
|
/*
|
|
* Select an appropriate JPEG colorspace for in_color_space.
|
|
*/
|
|
|
|
GLOBAL(void)
|
|
jpeg_default_colorspace (j_compress_ptr cinfo)
|
|
{
|
|
switch (cinfo->in_color_space) {
|
|
case JCS_UNKNOWN:
|
|
jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
|
|
break;
|
|
case JCS_GRAYSCALE:
|
|
jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
|
|
break;
|
|
case JCS_RGB:
|
|
jpeg_set_colorspace(cinfo, JCS_YCbCr);
|
|
break;
|
|
case JCS_YCbCr:
|
|
jpeg_set_colorspace(cinfo, JCS_YCbCr);
|
|
break;
|
|
case JCS_CMYK:
|
|
jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */
|
|
break;
|
|
case JCS_YCCK:
|
|
jpeg_set_colorspace(cinfo, JCS_YCCK);
|
|
break;
|
|
case JCS_BG_RGB:
|
|
/* No translation for now -- conversion to BG_YCC not yet supportet */
|
|
jpeg_set_colorspace(cinfo, JCS_BG_RGB);
|
|
break;
|
|
case JCS_BG_YCC:
|
|
jpeg_set_colorspace(cinfo, JCS_BG_YCC);
|
|
break;
|
|
default:
|
|
ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Set the JPEG colorspace, and choose colorspace-dependent default values.
|
|
*/
|
|
|
|
GLOBAL(void)
|
|
jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace)
|
|
{
|
|
jpeg_component_info * compptr;
|
|
int ci;
|
|
|
|
#define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \
|
|
(compptr = &cinfo->comp_info[index], \
|
|
compptr->component_id = (id), \
|
|
compptr->h_samp_factor = (hsamp), \
|
|
compptr->v_samp_factor = (vsamp), \
|
|
compptr->quant_tbl_no = (quant), \
|
|
compptr->dc_tbl_no = (dctbl), \
|
|
compptr->ac_tbl_no = (actbl) )
|
|
|
|
/* Safety check to ensure start_compress not called yet. */
|
|
if (cinfo->global_state != CSTATE_START)
|
|
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
|
|
|
|
/* For all colorspaces, we use Q and Huff tables 0 for luminance components,
|
|
* tables 1 for chrominance components.
|
|
*/
|
|
|
|
cinfo->jpeg_color_space = colorspace;
|
|
|
|
cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */
|
|
cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */
|
|
|
|
switch (colorspace) {
|
|
case JCS_UNKNOWN:
|
|
cinfo->num_components = cinfo->input_components;
|
|
if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS)
|
|
ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
|
|
MAX_COMPONENTS);
|
|
for (ci = 0; ci < cinfo->num_components; ci++) {
|
|
SET_COMP(ci, ci, 1,1, 0, 0,0);
|
|
}
|
|
break;
|
|
case JCS_GRAYSCALE:
|
|
cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
|
|
cinfo->num_components = 1;
|
|
/* JFIF specifies component ID 1 */
|
|
SET_COMP(0, 0x01, 1,1, 0, 0,0);
|
|
break;
|
|
case JCS_RGB:
|
|
cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */
|
|
cinfo->num_components = 3;
|
|
SET_COMP(0, 0x52 /* 'R' */, 1,1,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
|
|
SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
|
|
SET_COMP(2, 0x42 /* 'B' */, 1,1,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
|
|
break;
|
|
case JCS_YCbCr:
|
|
cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
|
|
cinfo->num_components = 3;
|
|
/* JFIF specifies component IDs 1,2,3 */
|
|
/* We default to 2x2 subsamples of chrominance */
|
|
SET_COMP(0, 0x01, 2,2, 0, 0,0);
|
|
SET_COMP(1, 0x02, 1,1, 1, 1,1);
|
|
SET_COMP(2, 0x03, 1,1, 1, 1,1);
|
|
break;
|
|
case JCS_CMYK:
|
|
cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */
|
|
cinfo->num_components = 4;
|
|
SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0);
|
|
SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0);
|
|
SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0);
|
|
SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0);
|
|
break;
|
|
case JCS_YCCK:
|
|
cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */
|
|
cinfo->num_components = 4;
|
|
SET_COMP(0, 0x01, 2,2, 0, 0,0);
|
|
SET_COMP(1, 0x02, 1,1, 1, 1,1);
|
|
SET_COMP(2, 0x03, 1,1, 1, 1,1);
|
|
SET_COMP(3, 0x04, 2,2, 0, 0,0);
|
|
break;
|
|
case JCS_BG_RGB:
|
|
cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
|
|
cinfo->JFIF_major_version = 2; /* Set JFIF major version = 2 */
|
|
cinfo->num_components = 3;
|
|
/* Add offset 0x20 to the normal R/G/B component IDs */
|
|
SET_COMP(0, 0x72 /* 'r' */, 1,1,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
|
|
SET_COMP(1, 0x67 /* 'g' */, 1,1, 0, 0,0);
|
|
SET_COMP(2, 0x62 /* 'b' */, 1,1,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0,
|
|
cinfo->color_transform == JCT_SUBTRACT_GREEN ? 1 : 0);
|
|
break;
|
|
case JCS_BG_YCC:
|
|
cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
|
|
cinfo->JFIF_major_version = 2; /* Set JFIF major version = 2 */
|
|
cinfo->num_components = 3;
|
|
/* Add offset 0x20 to the normal Cb/Cr component IDs */
|
|
/* We default to 2x2 subsamples of chrominance */
|
|
SET_COMP(0, 0x01, 2,2, 0, 0,0);
|
|
SET_COMP(1, 0x22, 1,1, 1, 1,1);
|
|
SET_COMP(2, 0x23, 1,1, 1, 1,1);
|
|
break;
|
|
default:
|
|
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef C_PROGRESSIVE_SUPPORTED
|
|
|
|
LOCAL(jpeg_scan_info *)
|
|
fill_a_scan (jpeg_scan_info * scanptr, int ci,
|
|
int Ss, int Se, int Ah, int Al)
|
|
/* Support routine: generate one scan for specified component */
|
|
{
|
|
scanptr->comps_in_scan = 1;
|
|
scanptr->component_index[0] = ci;
|
|
scanptr->Ss = Ss;
|
|
scanptr->Se = Se;
|
|
scanptr->Ah = Ah;
|
|
scanptr->Al = Al;
|
|
scanptr++;
|
|
return scanptr;
|
|
}
|
|
|
|
LOCAL(jpeg_scan_info *)
|
|
fill_scans (jpeg_scan_info * scanptr, int ncomps,
|
|
int Ss, int Se, int Ah, int Al)
|
|
/* Support routine: generate one scan for each component */
|
|
{
|
|
int ci;
|
|
|
|
for (ci = 0; ci < ncomps; ci++) {
|
|
scanptr->comps_in_scan = 1;
|
|
scanptr->component_index[0] = ci;
|
|
scanptr->Ss = Ss;
|
|
scanptr->Se = Se;
|
|
scanptr->Ah = Ah;
|
|
scanptr->Al = Al;
|
|
scanptr++;
|
|
}
|
|
return scanptr;
|
|
}
|
|
|
|
LOCAL(jpeg_scan_info *)
|
|
fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al)
|
|
/* Support routine: generate interleaved DC scan if possible, else N scans */
|
|
{
|
|
int ci;
|
|
|
|
if (ncomps <= MAX_COMPS_IN_SCAN) {
|
|
/* Single interleaved DC scan */
|
|
scanptr->comps_in_scan = ncomps;
|
|
for (ci = 0; ci < ncomps; ci++)
|
|
scanptr->component_index[ci] = ci;
|
|
scanptr->Ss = scanptr->Se = 0;
|
|
scanptr->Ah = Ah;
|
|
scanptr->Al = Al;
|
|
scanptr++;
|
|
} else {
|
|
/* Noninterleaved DC scan for each component */
|
|
scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al);
|
|
}
|
|
return scanptr;
|
|
}
|
|
|
|
|
|
/*
|
|
* Create a recommended progressive-JPEG script.
|
|
* cinfo->num_components and cinfo->jpeg_color_space must be correct.
|
|
*/
|
|
|
|
GLOBAL(void)
|
|
jpeg_simple_progression (j_compress_ptr cinfo)
|
|
{
|
|
int ncomps = cinfo->num_components;
|
|
int nscans;
|
|
jpeg_scan_info * scanptr;
|
|
|
|
/* Safety check to ensure start_compress not called yet. */
|
|
if (cinfo->global_state != CSTATE_START)
|
|
ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
|
|
|
|
/* Figure space needed for script. Calculation must match code below! */
|
|
if (ncomps == 3 &&
|
|
(cinfo->jpeg_color_space == JCS_YCbCr ||
|
|
cinfo->jpeg_color_space == JCS_BG_YCC)) {
|
|
/* Custom script for YCC color images. */
|
|
nscans = 10;
|
|
} else {
|
|
/* All-purpose script for other color spaces. */
|
|
if (ncomps > MAX_COMPS_IN_SCAN)
|
|
nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */
|
|
else
|
|
nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */
|
|
}
|
|
|
|
/* Allocate space for script.
|
|
* We need to put it in the permanent pool in case the application performs
|
|
* multiple compressions without changing the settings. To avoid a memory
|
|
* leak if jpeg_simple_progression is called repeatedly for the same JPEG
|
|
* object, we try to re-use previously allocated space, and we allocate
|
|
* enough space to handle YCC even if initially asked for grayscale.
|
|
*/
|
|
if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) {
|
|
cinfo->script_space_size = MAX(nscans, 10);
|
|
cinfo->script_space = (jpeg_scan_info *)
|
|
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
|
|
cinfo->script_space_size * SIZEOF(jpeg_scan_info));
|
|
}
|
|
scanptr = cinfo->script_space;
|
|
cinfo->scan_info = scanptr;
|
|
cinfo->num_scans = nscans;
|
|
|
|
if (ncomps == 3 &&
|
|
(cinfo->jpeg_color_space == JCS_YCbCr ||
|
|
cinfo->jpeg_color_space == JCS_BG_YCC)) {
|
|
/* Custom script for YCC color images. */
|
|
/* Initial DC scan */
|
|
scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
|
|
/* Initial AC scan: get some luma data out in a hurry */
|
|
scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2);
|
|
/* Chroma data is too small to be worth expending many scans on */
|
|
scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1);
|
|
scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1);
|
|
/* Complete spectral selection for luma AC */
|
|
scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2);
|
|
/* Refine next bit of luma AC */
|
|
scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1);
|
|
/* Finish DC successive approximation */
|
|
scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
|
|
/* Finish AC successive approximation */
|
|
scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0);
|
|
scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0);
|
|
/* Luma bottom bit comes last since it's usually largest scan */
|
|
scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0);
|
|
} else {
|
|
/* All-purpose script for other color spaces. */
|
|
/* Successive approximation first pass */
|
|
scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
|
|
scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2);
|
|
scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2);
|
|
/* Successive approximation second pass */
|
|
scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1);
|
|
/* Successive approximation final pass */
|
|
scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
|
|
scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0);
|
|
}
|
|
}
|
|
|
|
#endif /* C_PROGRESSIVE_SUPPORTED */
|