Home | History | Annotate | Download | only in jpeg
      1 /*
      2  * rdswitch.c
      3  *
      4  * Copyright (C) 1991-1996, Thomas G. Lane.
      5  * This file is part of the Independent JPEG Group's software.
      6  * For conditions of distribution and use, see the accompanying README file.
      7  *
      8  * This file contains routines to process some of cjpeg's more complicated
      9  * command-line switches.  Switches processed here are:
     10  *	-qtables file		Read quantization tables from text file
     11  *	-scans file		Read scan script from text file
     12  *	-qslots N[,N,...]	Set component quantization table selectors
     13  *	-sample HxV[,HxV,...]	Set component sampling factors
     14  */
     15 
     16 #include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
     17 #include <ctype.h>		/* to declare isdigit(), isspace() */
     18 
     19 
     20 LOCAL(int)
     21 text_getc (FILE * file)
     22 /* Read next char, skipping over any comments (# to end of line) */
     23 /* A comment/newline sequence is returned as a newline */
     24 {
     25   register int ch;
     26 
     27   ch = getc(file);
     28   if (ch == '#') {
     29     do {
     30       ch = getc(file);
     31     } while (ch != '\n' && ch != EOF);
     32   }
     33   return ch;
     34 }
     35 
     36 
     37 LOCAL(boolean)
     38 read_text_integer (FILE * file, long * result, int * termchar)
     39 /* Read an unsigned decimal integer from a file, store it in result */
     40 /* Reads one trailing character after the integer; returns it in termchar */
     41 {
     42   register int ch;
     43   register long val;
     44 
     45   /* Skip any leading whitespace, detect EOF */
     46   do {
     47     ch = text_getc(file);
     48     if (ch == EOF) {
     49       *termchar = ch;
     50       return FALSE;
     51     }
     52   } while (isspace(ch));
     53 
     54   if (! isdigit(ch)) {
     55     *termchar = ch;
     56     return FALSE;
     57   }
     58 
     59   val = ch - '0';
     60   while ((ch = text_getc(file)) != EOF) {
     61     if (! isdigit(ch))
     62       break;
     63     val *= 10;
     64     val += ch - '0';
     65   }
     66   *result = val;
     67   *termchar = ch;
     68   return TRUE;
     69 }
     70 
     71 
     72 GLOBAL(boolean)
     73 read_quant_tables (j_compress_ptr cinfo, char * filename,
     74 		   int scale_factor, boolean force_baseline)
     75 /* Read a set of quantization tables from the specified file.
     76  * The file is plain ASCII text: decimal numbers with whitespace between.
     77  * Comments preceded by '#' may be included in the file.
     78  * There may be one to NUM_QUANT_TBLS tables in the file, each of 64 values.
     79  * The tables are implicitly numbered 0,1,etc.
     80  * NOTE: does not affect the qslots mapping, which will default to selecting
     81  * table 0 for luminance (or primary) components, 1 for chrominance components.
     82  * You must use -qslots if you want a different component->table mapping.
     83  */
     84 {
     85   FILE * fp;
     86   int tblno, i, termchar;
     87   long val;
     88   unsigned int table[DCTSIZE2];
     89 
     90   if ((fp = fopen(filename, "r")) == NULL) {
     91     fprintf(stderr, "Can't open table file %s\n", filename);
     92     return FALSE;
     93   }
     94   tblno = 0;
     95 
     96   while (read_text_integer(fp, &val, &termchar)) { /* read 1st element of table */
     97     if (tblno >= NUM_QUANT_TBLS) {
     98       fprintf(stderr, "Too many tables in file %s\n", filename);
     99       fclose(fp);
    100       return FALSE;
    101     }
    102     table[0] = (unsigned int) val;
    103     for (i = 1; i < DCTSIZE2; i++) {
    104       if (! read_text_integer(fp, &val, &termchar)) {
    105 	fprintf(stderr, "Invalid table data in file %s\n", filename);
    106 	fclose(fp);
    107 	return FALSE;
    108       }
    109       table[i] = (unsigned int) val;
    110     }
    111     jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);
    112     tblno++;
    113   }
    114 
    115   if (termchar != EOF) {
    116     fprintf(stderr, "Non-numeric data in file %s\n", filename);
    117     fclose(fp);
    118     return FALSE;
    119   }
    120 
    121   fclose(fp);
    122   return TRUE;
    123 }
    124 
    125 
    126 #ifdef C_MULTISCAN_FILES_SUPPORTED
    127 
    128 LOCAL(boolean)
    129 read_scan_integer (FILE * file, long * result, int * termchar)
    130 /* Variant of read_text_integer that always looks for a non-space termchar;
    131  * this simplifies parsing of punctuation in scan scripts.
    132  */
    133 {
    134   register int ch;
    135 
    136   if (! read_text_integer(file, result, termchar))
    137     return FALSE;
    138   ch = *termchar;
    139   while (ch != EOF && isspace(ch))
    140     ch = text_getc(file);
    141   if (isdigit(ch)) {		/* oops, put it back */
    142     if (ungetc(ch, file) == EOF)
    143       return FALSE;
    144     ch = ' ';
    145   } else {
    146     /* Any separators other than ';' and ':' are ignored;
    147      * this allows user to insert commas, etc, if desired.
    148      */
    149     if (ch != EOF && ch != ';' && ch != ':')
    150       ch = ' ';
    151   }
    152   *termchar = ch;
    153   return TRUE;
    154 }
    155 
    156 
    157 GLOBAL(boolean)
    158 read_scan_script (j_compress_ptr cinfo, char * filename)
    159 /* Read a scan script from the specified text file.
    160  * Each entry in the file defines one scan to be emitted.
    161  * Entries are separated by semicolons ';'.
    162  * An entry contains one to four component indexes,
    163  * optionally followed by a colon ':' and four progressive-JPEG parameters.
    164  * The component indexes denote which component(s) are to be transmitted
    165  * in the current scan.  The first component has index 0.
    166  * Sequential JPEG is used if the progressive-JPEG parameters are omitted.
    167  * The file is free format text: any whitespace may appear between numbers
    168  * and the ':' and ';' punctuation marks.  Also, other punctuation (such
    169  * as commas or dashes) can be placed between numbers if desired.
    170  * Comments preceded by '#' may be included in the file.
    171  * Note: we do very little validity checking here;
    172  * jcmaster.c will validate the script parameters.
    173  */
    174 {
    175   FILE * fp;
    176   int scanno, ncomps, termchar;
    177   long val;
    178   jpeg_scan_info * scanptr;
    179 #define MAX_SCANS  100		/* quite arbitrary limit */
    180   jpeg_scan_info scans[MAX_SCANS];
    181 
    182   if ((fp = fopen(filename, "r")) == NULL) {
    183     fprintf(stderr, "Can't open scan definition file %s\n", filename);
    184     return FALSE;
    185   }
    186   scanptr = scans;
    187   scanno = 0;
    188 
    189   while (read_scan_integer(fp, &val, &termchar)) {
    190     if (scanno >= MAX_SCANS) {
    191       fprintf(stderr, "Too many scans defined in file %s\n", filename);
    192       fclose(fp);
    193       return FALSE;
    194     }
    195     scanptr->component_index[0] = (int) val;
    196     ncomps = 1;
    197     while (termchar == ' ') {
    198       if (ncomps >= MAX_COMPS_IN_SCAN) {
    199 	fprintf(stderr, "Too many components in one scan in file %s\n",
    200 		filename);
    201 	fclose(fp);
    202 	return FALSE;
    203       }
    204       if (! read_scan_integer(fp, &val, &termchar))
    205 	goto bogus;
    206       scanptr->component_index[ncomps] = (int) val;
    207       ncomps++;
    208     }
    209     scanptr->comps_in_scan = ncomps;
    210     if (termchar == ':') {
    211       if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
    212 	goto bogus;
    213       scanptr->Ss = (int) val;
    214       if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
    215 	goto bogus;
    216       scanptr->Se = (int) val;
    217       if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
    218 	goto bogus;
    219       scanptr->Ah = (int) val;
    220       if (! read_scan_integer(fp, &val, &termchar))
    221 	goto bogus;
    222       scanptr->Al = (int) val;
    223     } else {
    224       /* set non-progressive parameters */
    225       scanptr->Ss = 0;
    226       scanptr->Se = DCTSIZE2-1;
    227       scanptr->Ah = 0;
    228       scanptr->Al = 0;
    229     }
    230     if (termchar != ';' && termchar != EOF) {
    231 bogus:
    232       fprintf(stderr, "Invalid scan entry format in file %s\n", filename);
    233       fclose(fp);
    234       return FALSE;
    235     }
    236     scanptr++, scanno++;
    237   }
    238 
    239   if (termchar != EOF) {
    240     fprintf(stderr, "Non-numeric data in file %s\n", filename);
    241     fclose(fp);
    242     return FALSE;
    243   }
    244 
    245   if (scanno > 0) {
    246     /* Stash completed scan list in cinfo structure.
    247      * NOTE: for cjpeg's use, JPOOL_IMAGE is the right lifetime for this data,
    248      * but if you want to compress multiple images you'd want JPOOL_PERMANENT.
    249      */
    250     scanptr = (jpeg_scan_info *)
    251       (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    252 				  scanno * SIZEOF(jpeg_scan_info));
    253     MEMCOPY(scanptr, scans, scanno * SIZEOF(jpeg_scan_info));
    254     cinfo->scan_info = scanptr;
    255     cinfo->num_scans = scanno;
    256   }
    257 
    258   fclose(fp);
    259   return TRUE;
    260 }
    261 
    262 #endif /* C_MULTISCAN_FILES_SUPPORTED */
    263 
    264 
    265 GLOBAL(boolean)
    266 set_quant_slots (j_compress_ptr cinfo, char *arg)
    267 /* Process a quantization-table-selectors parameter string, of the form
    268  *     N[,N,...]
    269  * If there are more components than parameters, the last value is replicated.
    270  */
    271 {
    272   int val = 0;			/* default table # */
    273   int ci;
    274   char ch;
    275 
    276   for (ci = 0; ci < MAX_COMPONENTS; ci++) {
    277     if (*arg) {
    278       ch = ',';			/* if not set by sscanf, will be ',' */
    279       if (sscanf(arg, "%d%c", &val, &ch) < 1)
    280 	return FALSE;
    281       if (ch != ',')		/* syntax check */
    282 	return FALSE;
    283       if (val < 0 || val >= NUM_QUANT_TBLS) {
    284 	fprintf(stderr, "JPEG quantization tables are numbered 0..%d\n",
    285 		NUM_QUANT_TBLS-1);
    286 	return FALSE;
    287       }
    288       cinfo->comp_info[ci].quant_tbl_no = val;
    289       while (*arg && *arg++ != ',') /* advance to next segment of arg string */
    290 	;
    291     } else {
    292       /* reached end of parameter, set remaining components to last table */
    293       cinfo->comp_info[ci].quant_tbl_no = val;
    294     }
    295   }
    296   return TRUE;
    297 }
    298 
    299 
    300 GLOBAL(boolean)
    301 set_sample_factors (j_compress_ptr cinfo, char *arg)
    302 /* Process a sample-factors parameter string, of the form
    303  *     HxV[,HxV,...]
    304  * If there are more components than parameters, "1x1" is assumed for the rest.
    305  */
    306 {
    307   int ci, val1, val2;
    308   char ch1, ch2;
    309 
    310   for (ci = 0; ci < MAX_COMPONENTS; ci++) {
    311     if (*arg) {
    312       ch2 = ',';		/* if not set by sscanf, will be ',' */
    313       if (sscanf(arg, "%d%c%d%c", &val1, &ch1, &val2, &ch2) < 3)
    314 	return FALSE;
    315       if ((ch1 != 'x' && ch1 != 'X') || ch2 != ',') /* syntax check */
    316 	return FALSE;
    317       if (val1 <= 0 || val1 > 4 || val2 <= 0 || val2 > 4) {
    318 	fprintf(stderr, "JPEG sampling factors must be 1..4\n");
    319 	return FALSE;
    320       }
    321       cinfo->comp_info[ci].h_samp_factor = val1;
    322       cinfo->comp_info[ci].v_samp_factor = val2;
    323       while (*arg && *arg++ != ',') /* advance to next segment of arg string */
    324 	;
    325     } else {
    326       /* reached end of parameter, set remaining components to 1x1 sampling */
    327       cinfo->comp_info[ci].h_samp_factor = 1;
    328       cinfo->comp_info[ci].v_samp_factor = 1;
    329     }
    330   }
    331   return TRUE;
    332 }
    333