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-rw-r--r--src/libjpeg/jcparam.c610
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diff --git a/src/libjpeg/jcparam.c b/src/libjpeg/jcparam.c
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+/*
+ * jcparam.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 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;
+}
+
+
+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.
+ */
+{
+ /* These are the sample quantization tables given in JPEG spec section K.1.
+ * 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] = {
+ 17, 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
+ };
+
+ /* 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 three 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);
+}
+
+
+/*
+ * Huffman table setup routines
+ */
+
+LOCAL(void)
+add_huff_table (j_compress_ptr cinfo,
+ JHUFF_TBL **htblptr, const UINT8 *bits, const UINT8 *val)
+/* Define a Huffman table */
+{
+ int nsymbols, len;
+
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+
+ /* Copy the number-of-symbols-of-each-code-length counts */
+ MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
+
+ /* Validate the counts. We do this here mainly so we can copy the right
+ * number of symbols from the val[] array, without risking marching off
+ * the end of memory. jchuff.c will do a more thorough test later.
+ */
+ nsymbols = 0;
+ for (len = 1; len <= 16; len++)
+ nsymbols += bits[len];
+ if (nsymbols < 1 || nsymbols > 256)
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+
+ MEMCOPY((*htblptr)->huffval, val, nsymbols * SIZEOF(UINT8));
+
+ /* Initialize sent_table FALSE so table will be written to JPEG file. */
+ (*htblptr)->sent_table = FALSE;
+}
+
+
+LOCAL(void)
+std_huff_tables (j_compress_ptr cinfo)
+/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
+/* IMPORTANT: these are only valid for 8-bit data precision! */
+{
+ static const UINT8 bits_dc_luminance[17] =
+ { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
+ static const UINT8 val_dc_luminance[] =
+ { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
+
+ static const UINT8 bits_dc_chrominance[17] =
+ { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
+ static const UINT8 val_dc_chrominance[] =
+ { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
+
+ static const UINT8 bits_ac_luminance[17] =
+ { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
+ static const UINT8 val_ac_luminance[] =
+ { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
+ 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
+ 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
+ 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
+ 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
+ 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
+ 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+ 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
+ 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+ 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
+ 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
+ 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
+ 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
+ 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+ 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
+ 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
+ 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
+ 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
+ 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
+ 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
+ 0xf9, 0xfa };
+
+ static const UINT8 bits_ac_chrominance[17] =
+ { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
+ static const UINT8 val_ac_chrominance[] =
+ { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
+ 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
+ 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
+ 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
+ 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
+ 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
+ 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
+ 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
+ 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+ 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+ 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+ 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
+ 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
+ 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
+ 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
+ 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
+ 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
+ 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
+ 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
+ 0xf9, 0xfa };
+
+ add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[0],
+ bits_dc_luminance, val_dc_luminance);
+ add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[0],
+ bits_ac_luminance, val_ac_luminance);
+ add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[1],
+ bits_dc_chrominance, val_dc_chrominance);
+ add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[1],
+ bits_ac_chrominance, val_ac_chrominance);
+}
+
+
+/*
+ * 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->data_precision = BITS_IN_JSAMPLE;
+ /* Set up two quantization tables using default quality of 75 */
+ jpeg_set_quality(cinfo, 75, TRUE);
+ /* Set up two 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;
+
+ /* Use Huffman coding, not arithmetic coding, by default */
+ cinfo->arith_code = FALSE;
+
+ /* By default, don't do extra passes to optimize entropy coding */
+ cinfo->optimize_coding = FALSE;
+ /* The standard Huffman tables are only valid for 8-bit data precision.
+ * If the precision is higher, force optimization on so that usable
+ * tables will be computed. This test can be removed if default tables
+ * are supplied that are valid for the desired precision.
+ */
+ if (cinfo->data_precision > 8)
+ cinfo->optimize_coding = TRUE;
+
+ /* By default, use the simpler non-cosited sampling alignment */
+ cinfo->CCIR601_sampling = FALSE;
+
+ /* 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.
+ */
+ 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;
+
+ /* 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_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_UNKNOWN:
+ jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
+ 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_GRAYSCALE:
+ cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
+ cinfo->num_components = 1;
+ /* JFIF specifies component ID 1 */
+ SET_COMP(0, 1, 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, 0, 0,0);
+ SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
+ SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0);
+ 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, 1, 2,2, 0, 0,0);
+ SET_COMP(1, 2, 1,1, 1, 1,1);
+ SET_COMP(2, 3, 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, 1, 2,2, 0, 0,0);
+ SET_COMP(1, 2, 1,1, 1, 1,1);
+ SET_COMP(2, 3, 1,1, 1, 1,1);
+ SET_COMP(3, 4, 2,2, 0, 0,0);
+ break;
+ 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;
+ 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) {
+ /* Custom script for YCbCr 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 YCbCr 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) {
+ /* Custom script for YCbCr 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 */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-21 22:48:53 +0000