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- /*
- * rdswitch.c
- *
- * This file was part of the Independent JPEG Group's software:
- * Copyright (C) 1991-1996, Thomas G. Lane.
- * libjpeg-turbo Modifications:
- * Copyright (C) 2010, 2018, D. R. Commander.
- * For conditions of distribution and use, see the accompanying README.ijg
- * file.
- *
- * This file contains routines to process some of cjpeg's more complicated
- * command-line switches. Switches processed here are:
- * -qtables file Read quantization tables from text file
- * -scans file Read scan script from text file
- * -quality N[,N,...] Set quality ratings
- * -qslots N[,N,...] Set component quantization table selectors
- * -sample HxV[,HxV,...] Set component sampling factors
- */
- #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
- #include <ctype.h> /* to declare isdigit(), isspace() */
- LOCAL(int)
- text_getc (FILE *file)
- /* Read next char, skipping over any comments (# to end of line) */
- /* A comment/newline sequence is returned as a newline */
- {
- register int ch;
- ch = getc(file);
- if (ch == '#') {
- do {
- ch = getc(file);
- } while (ch != '\n' && ch != EOF);
- }
- return ch;
- }
- LOCAL(boolean)
- read_text_integer (FILE *file, long *result, int *termchar)
- /* Read an unsigned decimal integer from a file, store it in result */
- /* Reads one trailing character after the integer; returns it in termchar */
- {
- register int ch;
- register long val;
- /* Skip any leading whitespace, detect EOF */
- do {
- ch = text_getc(file);
- if (ch == EOF) {
- *termchar = ch;
- return FALSE;
- }
- } while (isspace(ch));
- if (! isdigit(ch)) {
- *termchar = ch;
- return FALSE;
- }
- val = ch - '0';
- while ((ch = text_getc(file)) != EOF) {
- if (! isdigit(ch))
- break;
- val *= 10;
- val += ch - '0';
- }
- *result = val;
- *termchar = ch;
- return TRUE;
- }
- #if JPEG_LIB_VERSION < 70
- static int q_scale_factor[NUM_QUANT_TBLS] = {100, 100, 100, 100};
- #endif
- GLOBAL(boolean)
- read_quant_tables(j_compress_ptr cinfo, char *filename, boolean force_baseline)
- /* Read a set of quantization tables from the specified file.
- * The file is plain ASCII text: decimal numbers with whitespace between.
- * Comments preceded by '#' may be included in the file.
- * There may be one to NUM_QUANT_TBLS tables in the file, each of 64 values.
- * The tables are implicitly numbered 0,1,etc.
- * NOTE: does not affect the qslots mapping, which will default to selecting
- * table 0 for luminance (or primary) components, 1 for chrominance components.
- * You must use -qslots if you want a different component->table mapping.
- */
- {
- FILE *fp;
- int tblno, i, termchar;
- long val;
- unsigned int table[DCTSIZE2];
- if ((fp = fopen(filename, "r")) == NULL) {
- fprintf(stderr, "Can't open table file %s\n", filename);
- return FALSE;
- }
- tblno = 0;
- while (read_text_integer(fp, &val, &termchar)) { /* read 1st element of table */
- if (tblno >= NUM_QUANT_TBLS) {
- fprintf(stderr, "Too many tables in file %s\n", filename);
- fclose(fp);
- return FALSE;
- }
- table[0] = (unsigned int) val;
- for (i = 1; i < DCTSIZE2; i++) {
- if (! read_text_integer(fp, &val, &termchar)) {
- fprintf(stderr, "Invalid table data in file %s\n", filename);
- fclose(fp);
- return FALSE;
- }
- table[i] = (unsigned int) val;
- }
- #if JPEG_LIB_VERSION >= 70
- jpeg_add_quant_table(cinfo, tblno, table, cinfo->q_scale_factor[tblno],
- force_baseline);
- #else
- jpeg_add_quant_table(cinfo, tblno, table, q_scale_factor[tblno],
- force_baseline);
- #endif
- tblno++;
- }
- if (termchar != EOF) {
- fprintf(stderr, "Non-numeric data in file %s\n", filename);
- fclose(fp);
- return FALSE;
- }
- fclose(fp);
- return TRUE;
- }
- #ifdef C_MULTISCAN_FILES_SUPPORTED
- LOCAL(boolean)
- read_scan_integer (FILE *file, long *result, int *termchar)
- /* Variant of read_text_integer that always looks for a non-space termchar;
- * this simplifies parsing of punctuation in scan scripts.
- */
- {
- register int ch;
- if (! read_text_integer(file, result, termchar))
- return FALSE;
- ch = *termchar;
- while (ch != EOF && isspace(ch))
- ch = text_getc(file);
- if (isdigit(ch)) { /* oops, put it back */
- if (ungetc(ch, file) == EOF)
- return FALSE;
- ch = ' ';
- } else {
- /* Any separators other than ';' and ':' are ignored;
- * this allows user to insert commas, etc, if desired.
- */
- if (ch != EOF && ch != ';' && ch != ':')
- ch = ' ';
- }
- *termchar = ch;
- return TRUE;
- }
- GLOBAL(boolean)
- read_scan_script (j_compress_ptr cinfo, char *filename)
- /* Read a scan script from the specified text file.
- * Each entry in the file defines one scan to be emitted.
- * Entries are separated by semicolons ';'.
- * An entry contains one to four component indexes,
- * optionally followed by a colon ':' and four progressive-JPEG parameters.
- * The component indexes denote which component(s) are to be transmitted
- * in the current scan. The first component has index 0.
- * Sequential JPEG is used if the progressive-JPEG parameters are omitted.
- * The file is free format text: any whitespace may appear between numbers
- * and the ':' and ';' punctuation marks. Also, other punctuation (such
- * as commas or dashes) can be placed between numbers if desired.
- * Comments preceded by '#' may be included in the file.
- * Note: we do very little validity checking here;
- * jcmaster.c will validate the script parameters.
- */
- {
- FILE *fp;
- int scanno, ncomps, termchar;
- long val;
- jpeg_scan_info *scanptr;
- #define MAX_SCANS 100 /* quite arbitrary limit */
- jpeg_scan_info scans[MAX_SCANS];
- if ((fp = fopen(filename, "r")) == NULL) {
- fprintf(stderr, "Can't open scan definition file %s\n", filename);
- return FALSE;
- }
- scanptr = scans;
- scanno = 0;
- while (read_scan_integer(fp, &val, &termchar)) {
- if (scanno >= MAX_SCANS) {
- fprintf(stderr, "Too many scans defined in file %s\n", filename);
- fclose(fp);
- return FALSE;
- }
- scanptr->component_index[0] = (int) val;
- ncomps = 1;
- while (termchar == ' ') {
- if (ncomps >= MAX_COMPS_IN_SCAN) {
- fprintf(stderr, "Too many components in one scan in file %s\n",
- filename);
- fclose(fp);
- return FALSE;
- }
- if (! read_scan_integer(fp, &val, &termchar))
- goto bogus;
- scanptr->component_index[ncomps] = (int) val;
- ncomps++;
- }
- scanptr->comps_in_scan = ncomps;
- if (termchar == ':') {
- if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
- goto bogus;
- scanptr->Ss = (int) val;
- if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
- goto bogus;
- scanptr->Se = (int) val;
- if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
- goto bogus;
- scanptr->Ah = (int) val;
- if (! read_scan_integer(fp, &val, &termchar))
- goto bogus;
- scanptr->Al = (int) val;
- } else {
- /* set non-progressive parameters */
- scanptr->Ss = 0;
- scanptr->Se = DCTSIZE2-1;
- scanptr->Ah = 0;
- scanptr->Al = 0;
- }
- if (termchar != ';' && termchar != EOF) {
- bogus:
- fprintf(stderr, "Invalid scan entry format in file %s\n", filename);
- fclose(fp);
- return FALSE;
- }
- scanptr++, scanno++;
- }
- if (termchar != EOF) {
- fprintf(stderr, "Non-numeric data in file %s\n", filename);
- fclose(fp);
- return FALSE;
- }
- if (scanno > 0) {
- /* Stash completed scan list in cinfo structure.
- * NOTE: for cjpeg's use, JPOOL_IMAGE is the right lifetime for this data,
- * but if you want to compress multiple images you'd want JPOOL_PERMANENT.
- */
- scanptr = (jpeg_scan_info *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- scanno * sizeof(jpeg_scan_info));
- MEMCOPY(scanptr, scans, scanno * sizeof(jpeg_scan_info));
- cinfo->scan_info = scanptr;
- cinfo->num_scans = scanno;
-
- /* Disable scan optimization if using custom scan */
- jpeg_c_set_bool_param(cinfo, JBOOLEAN_OPTIMIZE_SCANS, FALSE);
- }
- fclose(fp);
- return TRUE;
- }
- #endif /* C_MULTISCAN_FILES_SUPPORTED */
- #if JPEG_LIB_VERSION < 70
- /* These are the sample quantization tables given in Annex K (Clause K.1) of
- * Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994.
- * 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[9][DCTSIZE2] = {
- {
- /* JPEG Annex K
- */
- 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
- },
- {
- /* flat
- */
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16
- },
- {
- 12, 17, 20, 21, 30, 34, 56, 63,
- 18, 20, 20, 26, 28, 51, 61, 55,
- 19, 20, 21, 26, 33, 58, 69, 55,
- 26, 26, 26, 30, 46, 87, 86, 66,
- 31, 33, 36, 40, 46, 96, 100, 73,
- 40, 35, 46, 62, 81, 100, 111, 91,
- 46, 66, 76, 86, 102, 121, 120, 101,
- 68, 90, 90, 96, 113, 102, 105, 103
- },
- {
- /* From http://www.imagemagick.org/discourse-server/viewtopic.php?f=22&t=20333&p=98008#p98008
- */
- 16, 16, 16, 18, 25, 37, 56, 85,
- 16, 17, 20, 27, 34, 40, 53, 75,
- 16, 20, 24, 31, 43, 62, 91, 135,
- 18, 27, 31, 40, 53, 74, 106, 156,
- 25, 34, 43, 53, 69, 94, 131, 189,
- 37, 40, 62, 74, 94, 124, 169, 238,
- 56, 53, 91, 106, 131, 169, 226, 311,
- 85, 75, 135, 156, 189, 238, 311, 418
- },
- {
- 9, 10, 12, 14, 27, 32, 51, 62,
- 11, 12, 14, 19, 27, 44, 59, 73,
- 12, 14, 18, 25, 42, 59, 79, 78,
- 17, 18, 25, 42, 61, 92, 87, 92,
- 23, 28, 42, 75, 79, 112, 112, 99,
- 40, 42, 59, 84, 88, 124, 132, 111,
- 42, 64, 78, 95, 105, 126, 125, 99,
- 70, 75, 100, 102, 116, 100, 107, 98
- },
- {
- /* Relevance of human vision to JPEG-DCT compression (1992) Klein, Silverstein and Carney.
- */
- 10, 12, 14, 19, 26, 38, 57, 86,
- 12, 18, 21, 28, 35, 41, 54, 76,
- 14, 21, 25, 32, 44, 63, 92, 136,
- 19, 28, 32, 41, 54, 75, 107, 157,
- 26, 35, 44, 54, 70, 95, 132, 190,
- 38, 41, 63, 75, 95, 125, 170, 239,
- 57, 54, 92, 107, 132, 170, 227, 312,
- 86, 76, 136, 157, 190, 239, 312, 419
- },
- {
- /* DCTune perceptual optimization of compressed dental X-Rays (1997) Watson, Taylor, Borthwick
- */
- 7, 8, 10, 14, 23, 44, 95, 241,
- 8, 8, 11, 15, 25, 47, 102, 255,
- 10, 11, 13, 19, 31, 58, 127, 255,
- 14, 15, 19, 27, 44, 83, 181, 255,
- 23, 25, 31, 44, 72, 136, 255, 255,
- 44, 47, 58, 83, 136, 255, 255, 255,
- 95, 102, 127, 181, 255, 255, 255, 255,
- 241, 255, 255, 255, 255, 255, 255, 255
- },
- {
- /* A visual detection model for DCT coefficient quantization (12/9/93) Ahumada, Watson, Peterson
- */
- 15, 11, 11, 12, 15, 19, 25, 32,
- 11, 13, 10, 10, 12, 15, 19, 24,
- 11, 10, 14, 14, 16, 18, 22, 27,
- 12, 10, 14, 18, 21, 24, 28, 33,
- 15, 12, 16, 21, 26, 31, 36, 42,
- 19, 15, 18, 24, 31, 38, 45, 53,
- 25, 19, 22, 28, 36, 45, 55, 65,
- 32, 24, 27, 33, 42, 53, 65, 77
- },
- {
- /* An improved detection model for DCT coefficient quantization (1993) Peterson, Ahumada and Watson
- */
- 14, 10, 11, 14, 19, 25, 34, 45,
- 10, 11, 11, 12, 15, 20, 26, 33,
- 11, 11, 15, 18, 21, 25, 31, 38,
- 14, 12, 18, 24, 28, 33, 39, 47,
- 19, 15, 21, 28, 36, 43, 51, 59,
- 25, 20, 25, 33, 43, 54, 64, 74,
- 34, 26, 31, 39, 51, 64, 77, 91,
- 45, 33, 38, 47, 59, 74, 91, 108
- }
- };
- static const unsigned int std_chrominance_quant_tbl[9][DCTSIZE2] = {
- {
- /* JPEG Annex K
- */
- 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
- },
- {
- /* flat
- */
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16,
- 16, 16, 16, 16, 16, 16, 16, 16
- },
- {
- 8, 12, 15, 15, 86, 96, 96, 98,
- 13, 13, 15, 26, 90, 96, 99, 98,
- 12, 15, 18, 96, 99, 99, 99, 99,
- 17, 16, 90, 96, 99, 99, 99, 99,
- 96, 96, 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
- },
- {
- /* From http://www.imagemagick.org/discourse-server/viewtopic.php?f=22&t=20333&p=98008#p98008
- */
- 16, 16, 16, 18, 25, 37, 56, 85,
- 16, 17, 20, 27, 34, 40, 53, 75,
- 16, 20, 24, 31, 43, 62, 91, 135,
- 18, 27, 31, 40, 53, 74, 106, 156,
- 25, 34, 43, 53, 69, 94, 131, 189,
- 37, 40, 62, 74, 94, 124, 169, 238,
- 56, 53, 91, 106, 131, 169, 226, 311,
- 85, 75, 135, 156, 189, 238, 311, 418
- },
- {
- 9, 10, 17, 19, 62, 89, 91, 97,
- 12, 13, 18, 29, 84, 91, 88, 98,
- 14, 19, 29, 93, 95, 95, 98, 97,
- 20, 26, 84, 88, 95, 95, 98, 94,
- 26, 86, 91, 93, 97, 99, 98, 99,
- 99, 100, 98, 99, 99, 99, 99, 99,
- 99, 99, 99, 99, 99, 99, 99, 99,
- 97, 97, 99, 99, 99, 99, 97, 99
- },
- {
- /* Relevance of human vision to JPEG-DCT compression (1992) Klein, Silverstein and Carney.
- * Copied from luma
- */
- 10, 12, 14, 19, 26, 38, 57, 86,
- 12, 18, 21, 28, 35, 41, 54, 76,
- 14, 21, 25, 32, 44, 63, 92, 136,
- 19, 28, 32, 41, 54, 75, 107, 157,
- 26, 35, 44, 54, 70, 95, 132, 190,
- 38, 41, 63, 75, 95, 125, 170, 239,
- 57, 54, 92, 107, 132, 170, 227, 312,
- 86, 76, 136, 157, 190, 239, 312, 419
- },
- {
- /* DCTune perceptual optimization of compressed dental X-Rays (1997) Watson, Taylor, Borthwick
- * Copied from luma
- */
- 7, 8, 10, 14, 23, 44, 95, 241,
- 8, 8, 11, 15, 25, 47, 102, 255,
- 10, 11, 13, 19, 31, 58, 127, 255,
- 14, 15, 19, 27, 44, 83, 181, 255,
- 23, 25, 31, 44, 72, 136, 255, 255,
- 44, 47, 58, 83, 136, 255, 255, 255,
- 95, 102, 127, 181, 255, 255, 255, 255,
- 241, 255, 255, 255, 255, 255, 255, 255
- },
- {
- /* A visual detection model for DCT coefficient quantization (12/9/93) Ahumada, Watson, Peterson
- * Copied from luma
- */
- 15, 11, 11, 12, 15, 19, 25, 32,
- 11, 13, 10, 10, 12, 15, 19, 24,
- 11, 10, 14, 14, 16, 18, 22, 27,
- 12, 10, 14, 18, 21, 24, 28, 33,
- 15, 12, 16, 21, 26, 31, 36, 42,
- 19, 15, 18, 24, 31, 38, 45, 53,
- 25, 19, 22, 28, 36, 45, 55, 65,
- 32, 24, 27, 33, 42, 53, 65, 77
- },
- {
- /* An improved detection model for DCT coefficient quantization (1993) Peterson, Ahumada and Watson
- * Copied from luma
- */
- 14, 10, 11, 14, 19, 25, 34, 45,
- 10, 11, 11, 12, 15, 20, 26, 33,
- 11, 11, 15, 18, 21, 25, 31, 38,
- 14, 12, 18, 24, 28, 33, 39, 47,
- 19, 15, 21, 28, 36, 43, 51, 59,
- 25, 20, 25, 33, 43, 54, 64, 74,
- 34, 26, 31, 39, 51, 64, 77, 91,
- 45, 33, 38, 47, 59, 74, 91, 108
- }
- };
- LOCAL(void)
- jpeg_default_qtables (j_compress_ptr cinfo, boolean force_baseline)
- {
- int quant_tbl_master_idx = 0;
- if (jpeg_c_int_param_supported(cinfo, JINT_BASE_QUANT_TBL_IDX))
- quant_tbl_master_idx = jpeg_c_get_int_param(cinfo, JINT_BASE_QUANT_TBL_IDX);
-
- jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl[quant_tbl_master_idx],
- q_scale_factor[0], force_baseline);
- jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl[quant_tbl_master_idx],
- q_scale_factor[1], force_baseline);
- }
- #endif
- GLOBAL(boolean)
- set_quality_ratings (j_compress_ptr cinfo, char *arg, boolean force_baseline)
- /* Process a quality-ratings parameter string, of the form
- * N[,N,...]
- * If there are more q-table slots than parameters, the last value is replicated.
- */
- {
- float val = 75.f; /* default value */
- int tblno;
- char ch;
- for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
- if (*arg) {
- ch = ','; /* if not set by sscanf, will be ',' */
- if (sscanf(arg, "%f%c", &val, &ch) < 1)
- return FALSE;
- if (ch != ',') /* syntax check */
- return FALSE;
- /* Convert user 0-100 rating to percentage scaling */
- #if JPEG_LIB_VERSION >= 70
- cinfo->q_scale_factor[tblno] = jpeg_float_quality_scaling(val);
- #else
- q_scale_factor[tblno] = jpeg_float_quality_scaling(val);
- #endif
- while (*arg && *arg++ != ','); /* advance to next segment of arg
- string */
- } else {
- /* reached end of parameter, set remaining factors to last value */
- #if JPEG_LIB_VERSION >= 70
- cinfo->q_scale_factor[tblno] = jpeg_float_quality_scaling(val);
- #else
- q_scale_factor[tblno] = jpeg_float_quality_scaling(val);
- #endif
- }
- }
- jpeg_default_qtables(cinfo, force_baseline);
- /* For some images chroma subsampling significantly degrades color quality,
- making it impossible to achieve high visual quality regardless of quality setting.
- To make the quality setting more intuitive, disable subsampling when high-quality
- color is desired. */
- if (val >= 90) {
- set_sample_factors(cinfo, "1x1");
- } else if (val >= 80) {
- set_sample_factors(cinfo, "2x1");
- }
- return TRUE;
- }
- GLOBAL(boolean)
- set_quant_slots (j_compress_ptr cinfo, char *arg)
- /* Process a quantization-table-selectors parameter string, of the form
- * N[,N,...]
- * If there are more components than parameters, the last value is replicated.
- */
- {
- int val = 0; /* default table # */
- int ci;
- char ch;
- for (ci = 0; ci < MAX_COMPONENTS; ci++) {
- if (*arg) {
- ch = ','; /* if not set by sscanf, will be ',' */
- if (sscanf(arg, "%d%c", &val, &ch) < 1)
- return FALSE;
- if (ch != ',') /* syntax check */
- return FALSE;
- if (val < 0 || val >= NUM_QUANT_TBLS) {
- fprintf(stderr, "JPEG quantization tables are numbered 0..%d\n",
- NUM_QUANT_TBLS-1);
- return FALSE;
- }
- cinfo->comp_info[ci].quant_tbl_no = val;
- while (*arg && *arg++ != ','); /* advance to next segment of arg
- string */
- } else {
- /* reached end of parameter, set remaining components to last table */
- cinfo->comp_info[ci].quant_tbl_no = val;
- }
- }
- return TRUE;
- }
- GLOBAL(boolean)
- set_sample_factors (j_compress_ptr cinfo, char *arg)
- /* Process a sample-factors parameter string, of the form
- * HxV[,HxV,...]
- * If there are more components than parameters, "1x1" is assumed for the rest.
- */
- {
- int ci, val1, val2;
- char ch1, ch2;
- for (ci = 0; ci < MAX_COMPONENTS; ci++) {
- if (*arg) {
- ch2 = ','; /* if not set by sscanf, will be ',' */
- if (sscanf(arg, "%d%c%d%c", &val1, &ch1, &val2, &ch2) < 3)
- return FALSE;
- if ((ch1 != 'x' && ch1 != 'X') || ch2 != ',') /* syntax check */
- return FALSE;
- if (val1 <= 0 || val1 > 4 || val2 <= 0 || val2 > 4) {
- fprintf(stderr, "JPEG sampling factors must be 1..4\n");
- return FALSE;
- }
- cinfo->comp_info[ci].h_samp_factor = val1;
- cinfo->comp_info[ci].v_samp_factor = val2;
- while (*arg && *arg++ != ','); /* advance to next segment of arg
- string */
- } else {
- /* reached end of parameter, set remaining components to 1x1 sampling */
- cinfo->comp_info[ci].h_samp_factor = 1;
- cinfo->comp_info[ci].v_samp_factor = 1;
- }
- }
- return TRUE;
- }
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