workbench/libs/jpeg/wrjpgcom.c

   1 /*
   2  * wrjpgcom.c
   3  *
   4  * Copyright (C) 1994-1997, 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 a very simple stand-alone application that inserts
   9  * user-supplied text as a COM (comment) marker in a JFIF file.
  10  * This may be useful as an example of the minimum logic needed to parse
  11  * JPEG markers.
  12  */
  13
  14 #define JPEG_CJPEG_DJPEG        /* to get the command-line config symbols */
  15 #include "jinclude.h"           /* get auto-config symbols, <stdio.h> */
  16
  17 #ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc() */
  18 extern void * malloc ();
  19 #endif
  20 #include <ctype.h>              /* to declare isupper(), tolower() */
  21 #ifdef USE_SETMODE
  22 #include <fcntl.h>              /* to declare setmode()'s parameter macros */
  23 /* If you have setmode() but not <io.h>, just delete this line: */
  24 #include <io.h>                 /* to declare setmode() */
  25 #endif
  26
  27 #ifdef USE_CCOMMAND             /* command-line reader for Macintosh */
  28 #ifdef __MWERKS__
  29 #include <SIOUX.h>              /* Metrowerks needs this */
  30 #include <console.h>            /* ... and this */
  31 #endif
  32 #ifdef THINK_C
  33 #include <console.h>            /* Think declares it here */
  34 #endif
  35 #endif
  36
  37 #ifdef DONT_USE_B_MODE          /* define mode parameters for fopen() */
  38 #define READ_BINARY     "r"
  39 #define WRITE_BINARY    "w"
  40 #else
  41 #ifdef VMS                      /* VMS is very nonstandard */
  42 #define READ_BINARY     "rb", "ctx=stm"
  43 #define WRITE_BINARY    "wb", "ctx=stm"
  44 #else                           /* standard ANSI-compliant case */
  45 #define READ_BINARY     "rb"
  46 #define WRITE_BINARY    "wb"
  47 #endif
  48 #endif
  49
  50 #ifndef EXIT_FAILURE            /* define exit() codes if not provided */
  51 #define EXIT_FAILURE  1
  52 #endif
  53 #ifndef EXIT_SUCCESS
  54 #ifdef VMS
  55 #define EXIT_SUCCESS  1         /* VMS is very nonstandard */
  56 #else
  57 #define EXIT_SUCCESS  0
  58 #endif
  59 #endif
  60
  61 /* Reduce this value if your malloc() can't allocate blocks up to 64K.
  62  * On DOS, compiling in large model is usually a better solution.
  63  */
  64
  65 #ifndef MAX_COM_LENGTH
  66 #define MAX_COM_LENGTH 65000L   /* must be <= 65533 in any case */
  67 #endif
  68
  69
  70 /*
  71  * These macros are used to read the input file and write the output file.
  72  * To reuse this code in another application, you might need to change these.
  73  */
  74
  75 static FILE * infile;           /* input JPEG file */
  76
  77 /* Return next input byte, or EOF if no more */
  78 #define NEXTBYTE()  getc(infile)
  79
  80 static FILE * outfile;          /* output JPEG file */
  81
  82 /* Emit an output byte */
  83 #define PUTBYTE(x)  putc((x), outfile)
  84
  85
  86 /* Error exit handler */
  87 #define ERREXIT(msg)  (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE))
  88
  89
  90 /* Read one byte, testing for EOF */
  91 static int
  92 read_1_byte (void)
  93 {
  94   int c;
  95
  96   c = NEXTBYTE();
  97   if (c == EOF)
  98     ERREXIT("Premature EOF in JPEG file");
  99   return c;
 100 }
 101
 102 /* Read 2 bytes, convert to unsigned int */
 103 /* All 2-byte quantities in JPEG markers are MSB first */
 104 static unsigned int
 105 read_2_bytes (void)
 106 {
 107   int c1, c2;
 108
 109   c1 = NEXTBYTE();
 110   if (c1 == EOF)
 111     ERREXIT("Premature EOF in JPEG file");
 112   c2 = NEXTBYTE();
 113   if (c2 == EOF)
 114     ERREXIT("Premature EOF in JPEG file");
 115   return (((unsigned int) c1) << 8) + ((unsigned int) c2);
 116 }
 117
 118
 119 /* Routines to write data to output file */
 120
 121 static void
 122 write_1_byte (int c)
 123 {
 124   PUTBYTE(c);
 125 }
 126
 127 static void
 128 write_2_bytes (unsigned int val)
 129 {
 130   PUTBYTE((val >> 8) & 0xFF);
 131   PUTBYTE(val & 0xFF);
 132 }
 133
 134 static void
 135 write_marker (int marker)
 136 {
 137   PUTBYTE(0xFF);
 138   PUTBYTE(marker);
 139 }
 140
 141 static void
 142 copy_rest_of_file (void)
 143 {
 144   int c;
 145
 146   while ((c = NEXTBYTE()) != EOF)
 147     PUTBYTE(c);
 148 }
 149
 150
 151 /*
 152  * JPEG markers consist of one or more 0xFF bytes, followed by a marker
 153  * code byte (which is not an FF).  Here are the marker codes of interest
 154  * in this program.  (See jdmarker.c for a more complete list.)
 155  */
 156
 157 #define M_SOF0  0xC0            /* Start Of Frame N */
 158 #define M_SOF1  0xC1            /* N indicates which compression process */
 159 #define M_SOF2  0xC2            /* Only SOF0-SOF2 are now in common use */
 160 #define M_SOF3  0xC3
 161 #define M_SOF5  0xC5            /* NB: codes C4 and CC are NOT SOF markers */
 162 #define M_SOF6  0xC6
 163 #define M_SOF7  0xC7
 164 #define M_SOF9  0xC9
 165 #define M_SOF10 0xCA
 166 #define M_SOF11 0xCB
 167 #define M_SOF13 0xCD
 168 #define M_SOF14 0xCE
 169 #define M_SOF15 0xCF
 170 #define M_SOI   0xD8            /* Start Of Image (beginning of datastream) */
 171 #define M_EOI   0xD9            /* End Of Image (end of datastream) */
 172 #define M_SOS   0xDA            /* Start Of Scan (begins compressed data) */
 173 #define M_COM   0xFE            /* COMment */
 174
 175
 176 /*
 177  * Find the next JPEG marker and return its marker code.
 178  * We expect at least one FF byte, possibly more if the compressor used FFs
 179  * to pad the file.  (Padding FFs will NOT be replicated in the output file.)
 180  * There could also be non-FF garbage between markers.  The treatment of such
 181  * garbage is unspecified; we choose to skip over it but emit a warning msg.
 182  * NB: this routine must not be used after seeing SOS marker, since it will
 183  * not deal correctly with FF/00 sequences in the compressed image data...
 184  */
 185
 186 static int
 187 next_marker (void)
 188 {
 189   int c;
 190   int discarded_bytes = 0;
 191
 192   /* Find 0xFF byte; count and skip any non-FFs. */
 193   c = read_1_byte();
 194   while (c != 0xFF) {
 195     discarded_bytes++;
 196     c = read_1_byte();
 197   }
 198   /* Get marker code byte, swallowing any duplicate FF bytes.  Extra FFs
 199    * are legal as pad bytes, so don't count them in discarded_bytes.
 200    */
 201   do {
 202     c = read_1_byte();
 203   } while (c == 0xFF);
 204
 205   if (discarded_bytes != 0) {
 206     fprintf(stderr, "Warning: garbage data found in JPEG file\n");
 207   }
 208
 209   return c;
 210 }
 211
 212
 213 /*
 214  * Read the initial marker, which should be SOI.
 215  * For a JFIF file, the first two bytes of the file should be literally
 216  * 0xFF M_SOI.  To be more general, we could use next_marker, but if the
 217  * input file weren't actually JPEG at all, next_marker might read the whole
 218  * file and then return a misleading error message...
 219  */
 220
 221 static int
 222 first_marker (void)
 223 {
 224   int c1, c2;
 225
 226   c1 = NEXTBYTE();
 227   c2 = NEXTBYTE();
 228   if (c1 != 0xFF || c2 != M_SOI)
 229     ERREXIT("Not a JPEG file");
 230   return c2;
 231 }
 232
 233
 234 /*
 235  * Most types of marker are followed by a variable-length parameter segment.
 236  * This routine skips over the parameters for any marker we don't otherwise
 237  * want to process.
 238  * Note that we MUST skip the parameter segment explicitly in order not to
 239  * be fooled by 0xFF bytes that might appear within the parameter segment;
 240  * such bytes do NOT introduce new markers.
 241  */
 242
 243 static void
 244 copy_variable (void)
 245 /* Copy an unknown or uninteresting variable-length marker */
 246 {
 247   unsigned int length;
 248
 249   /* Get the marker parameter length count */
 250   length = read_2_bytes();
 251   write_2_bytes(length);
 252   /* Length includes itself, so must be at least 2 */
 253   if (length < 2)
 254     ERREXIT("Erroneous JPEG marker length");
 255   length -= 2;
 256   /* Skip over the remaining bytes */
 257   while (length > 0) {
 258     write_1_byte(read_1_byte());
 259     length--;
 260   }
 261 }
 262
 263 static void
 264 skip_variable (void)
 265 /* Skip over an unknown or uninteresting variable-length marker */
 266 {
 267   unsigned int length;
 268
 269   /* Get the marker parameter length count */
 270   length = read_2_bytes();
 271   /* Length includes itself, so must be at least 2 */
 272   if (length < 2)
 273     ERREXIT("Erroneous JPEG marker length");
 274   length -= 2;
 275   /* Skip over the remaining bytes */
 276   while (length > 0) {
 277     (void) read_1_byte();
 278     length--;
 279   }
 280 }
 281
 282
 283 /*
 284  * Parse the marker stream until SOFn or EOI is seen;
 285  * copy data to output, but discard COM markers unless keep_COM is true.
 286  */
 287
 288 static int
 289 scan_JPEG_header (int keep_COM)
 290 {
 291   int marker;
 292
 293   /* Expect SOI at start of file */
 294   if (first_marker() != M_SOI)
 295     ERREXIT("Expected SOI marker first");
 296   write_marker(M_SOI);
 297
 298   /* Scan miscellaneous markers until we reach SOFn. */
 299   for (;;) {
 300     marker = next_marker();
 301     switch (marker) {
 302       /* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be,
 303        * treated as SOFn.  C4 in particular is actually DHT.
 304        */
 305     case M_SOF0:                /* Baseline */
 306     case M_SOF1:                /* Extended sequential, Huffman */
 307     case M_SOF2:                /* Progressive, Huffman */
 308     case M_SOF3:                /* Lossless, Huffman */
 309     case M_SOF5:                /* Differential sequential, Huffman */
 310     case M_SOF6:                /* Differential progressive, Huffman */
 311     case M_SOF7:                /* Differential lossless, Huffman */
 312     case M_SOF9:                /* Extended sequential, arithmetic */
 313     case M_SOF10:               /* Progressive, arithmetic */
 314     case M_SOF11:               /* Lossless, arithmetic */
 315     case M_SOF13:               /* Differential sequential, arithmetic */
 316     case M_SOF14:               /* Differential progressive, arithmetic */
 317     case M_SOF15:               /* Differential lossless, arithmetic */
 318       return marker;
 319
 320     case M_SOS:                 /* should not see compressed data before SOF */
 321       ERREXIT("SOS without prior SOFn");
 322       break;
 323
 324     case M_EOI:                 /* in case it's a tables-only JPEG stream */
 325       return marker;
 326
 327     case M_COM:                 /* Existing COM: conditionally discard */
 328       if (keep_COM) {
 329         write_marker(marker);
 330         copy_variable();
 331       } else {
 332         skip_variable();
 333       }
 334       break;
 335
 336     default:                    /* Anything else just gets copied */
 337       write_marker(marker);
 338       copy_variable();          /* we assume it has a parameter count... */
 339       break;
 340     }
 341   } /* end loop */
 342 }
 343
 344
 345 /* Command line parsing code */
 346
 347 static const char * progname;   /* program name for error messages */
 348
 349
 350 static void
 351 usage (void)
 352 /* complain about bad command line */
 353 {
 354   fprintf(stderr, "wrjpgcom inserts a textual comment in a JPEG file.\n");
 355   fprintf(stderr, "You can add to or replace any existing comment(s).\n");
 356
 357   fprintf(stderr, "Usage: %s [switches] ", progname);
 358 #ifdef TWO_FILE_COMMANDLINE
 359   fprintf(stderr, "inputfile outputfile\n");
 360 #else
 361   fprintf(stderr, "[inputfile]\n");
 362 #endif
 363
 364   fprintf(stderr, "Switches (names may be abbreviated):\n");
 365   fprintf(stderr, "  -replace         Delete any existing comments\n");
 366   fprintf(stderr, "  -comment \"text\"  Insert comment with given text\n");
 367   fprintf(stderr, "  -cfile name      Read comment from named file\n");
 368   fprintf(stderr, "Notice that you must put quotes around the comment text\n");
 369   fprintf(stderr, "when you use -comment.\n");
 370   fprintf(stderr, "If you do not give either -comment or -cfile on the command line,\n");
 371   fprintf(stderr, "then the comment text is read from standard input.\n");
 372   fprintf(stderr, "It can be multiple lines, up to %u characters total.\n",
 373           (unsigned int) MAX_COM_LENGTH);
 374 #ifndef TWO_FILE_COMMANDLINE
 375   fprintf(stderr, "You must specify an input JPEG file name when supplying\n");
 376   fprintf(stderr, "comment text from standard input.\n");
 377 #endif
 378
 379   exit(EXIT_FAILURE);
 380 }
 381
 382
 383 static int
 384 keymatch (char * arg, const char * keyword, int minchars)
 385 /* Case-insensitive matching of (possibly abbreviated) keyword switches. */
 386 /* keyword is the constant keyword (must be lower case already), */
 387 /* minchars is length of minimum legal abbreviation. */
 388 {
 389   register int ca, ck;
 390   register int nmatched = 0;
 391
 392   while ((ca = *arg++) != '\0') {
 393     if ((ck = *keyword++) == '\0')
 394       return 0;                 /* arg longer than keyword, no good */
 395     if (isupper(ca))            /* force arg to lcase (assume ck is already) */
 396       ca = tolower(ca);
 397     if (ca != ck)
 398       return 0;                 /* no good */
 399     nmatched++;                 /* count matched characters */
 400   }
 401   /* reached end of argument; fail if it's too short for unique abbrev */
 402   if (nmatched < minchars)
 403     return 0;
 404   return 1;                     /* A-OK */
 405 }
 406
 407
 408 /*
 409  * The main program.
 410  */
 411
 412 int
 413 main (int argc, char **argv)
 414 {
 415   int argn;
 416   char * arg;
 417   int keep_COM = 1;
 418   char * comment_arg = NULL;
 419   FILE * comment_file = NULL;
 420   unsigned int comment_length = 0;
 421   int marker;
 422
 423   /* On Mac, fetch a command line. */
 424 #ifdef USE_CCOMMAND
 425   argc = ccommand(&argv);
 426 #endif
 427
 428   progname = argv[0];
 429   if (progname == NULL || progname[0] == 0)
 430     progname = "wrjpgcom";      /* in case C library doesn't provide it */
 431
 432   /* Parse switches, if any */
 433   for (argn = 1; argn < argc; argn++) {
 434     arg = argv[argn];
 435     if (arg[0] != '-')
 436       break;                    /* not switch, must be file name */
 437     arg++;                      /* advance over '-' */
 438     if (keymatch(arg, "replace", 1)) {
 439       keep_COM = 0;
 440     } else if (keymatch(arg, "cfile", 2)) {
 441       if (++argn >= argc) usage();
 442       if ((comment_file = fopen(argv[argn], "r")) == NULL) {
 443         fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
 444         exit(EXIT_FAILURE);
 445       }
 446     } else if (keymatch(arg, "comment", 1)) {
 447       if (++argn >= argc) usage();
 448       comment_arg = argv[argn];
 449       /* If the comment text starts with '"', then we are probably running
 450        * under MS-DOG and must parse out the quoted string ourselves.  Sigh.
 451        */
 452       if (comment_arg[0] == '"') {
 453         comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
 454         if (comment_arg == NULL)
 455           ERREXIT("Insufficient memory");
 456         strcpy(comment_arg, argv[argn]+1);
 457         for (;;) {
 458           comment_length = (unsigned int) strlen(comment_arg);
 459           if (comment_length > 0 && comment_arg[comment_length-1] == '"') {
 460             comment_arg[comment_length-1] = '\0'; /* zap terminating quote */
 461             break;
 462           }
 463           if (++argn >= argc)
 464             ERREXIT("Missing ending quote mark");
 465           strcat(comment_arg, " ");
 466           strcat(comment_arg, argv[argn]);
 467         }
 468       }
 469       comment_length = (unsigned int) strlen(comment_arg);
 470     } else
 471       usage();
 472   }
 473
 474   /* Cannot use both -comment and -cfile. */
 475   if (comment_arg != NULL && comment_file != NULL)
 476     usage();
 477   /* If there is neither -comment nor -cfile, we will read the comment text
 478    * from stdin; in this case there MUST be an input JPEG file name.
 479    */
 480   if (comment_arg == NULL && comment_file == NULL && argn >= argc)
 481     usage();
 482
 483   /* Open the input file. */
 484   if (argn < argc) {
 485     if ((infile = fopen(argv[argn], READ_BINARY)) == NULL) {
 486       fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
 487       exit(EXIT_FAILURE);
 488     }
 489   } else {
 490     /* default input file is stdin */
 491 #ifdef USE_SETMODE              /* need to hack file mode? */
 492     setmode(fileno(stdin), O_BINARY);
 493 #endif
 494 #ifdef USE_FDOPEN               /* need to re-open in binary mode? */
 495     if ((infile = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
 496       fprintf(stderr, "%s: can't open stdin\n", progname);
 497       exit(EXIT_FAILURE);
 498     }
 499 #else
 500     infile = stdin;
 501 #endif
 502   }
 503
 504   /* Open the output file. */
 505 #ifdef TWO_FILE_COMMANDLINE
 506   /* Must have explicit output file name */
 507   if (argn != argc-2) {
 508     fprintf(stderr, "%s: must name one input and one output file\n",
 509             progname);
 510     usage();
 511   }
 512   if ((outfile = fopen(argv[argn+1], WRITE_BINARY)) == NULL) {
 513     fprintf(stderr, "%s: can't open %s\n", progname, argv[argn+1]);
 514     exit(EXIT_FAILURE);
 515   }
 516 #else
 517   /* Unix style: expect zero or one file name */
 518   if (argn < argc-1) {
 519     fprintf(stderr, "%s: only one input file\n", progname);
 520     usage();
 521   }
 522   /* default output file is stdout */
 523 #ifdef USE_SETMODE              /* need to hack file mode? */
 524   setmode(fileno(stdout), O_BINARY);
 525 #endif
 526 #ifdef USE_FDOPEN               /* need to re-open in binary mode? */
 527   if ((outfile = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
 528     fprintf(stderr, "%s: can't open stdout\n", progname);
 529     exit(EXIT_FAILURE);
 530   }
 531 #else
 532   outfile = stdout;
 533 #endif
 534 #endif /* TWO_FILE_COMMANDLINE */
 535
 536   /* Collect comment text from comment_file or stdin, if necessary */
 537   if (comment_arg == NULL) {
 538     FILE * src_file;
 539     int c;
 540
 541     comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
 542     if (comment_arg == NULL)
 543       ERREXIT("Insufficient memory");
 544     comment_length = 0;
 545     src_file = (comment_file != NULL ? comment_file : stdin);
 546     while ((c = getc(src_file)) != EOF) {
 547       if (comment_length >= (unsigned int) MAX_COM_LENGTH) {
 548         fprintf(stderr, "Comment text may not exceed %u bytes\n",
 549                 (unsigned int) MAX_COM_LENGTH);
 550         exit(EXIT_FAILURE);
 551       }
 552       comment_arg[comment_length++] = (char) c;
 553     }
 554     if (comment_file != NULL)
 555       fclose(comment_file);
 556   }
 557
 558   /* Copy JPEG headers until SOFn marker;
 559    * we will insert the new comment marker just before SOFn.
 560    * This (a) causes the new comment to appear after, rather than before,
 561    * existing comments; and (b) ensures that comments come after any JFIF
 562    * or JFXX markers, as required by the JFIF specification.
 563    */
 564   marker = scan_JPEG_header(keep_COM);
 565   /* Insert the new COM marker, but only if nonempty text has been supplied */
 566   if (comment_length > 0) {
 567     write_marker(M_COM);
 568     write_2_bytes(comment_length + 2);
 569     while (comment_length > 0) {
 570       write_1_byte(*comment_arg++);
 571       comment_length--;
 572     }
 573   }
 574   /* Duplicate the remainder of the source file.
 575    * Note that any COM markers occuring after SOF will not be touched.
 576    */
 577   write_marker(marker);
 578   copy_rest_of_file();
 579
 580   /* All done. */
 581   exit(EXIT_SUCCESS);
 582   return 0;                     /* suppress no-return-value warnings */
 583 }