workbench/libs/jpeg/wrjpgcom.c

   1 /*
   2  * wrjpgcom.c
   3  *
   4  * Copyright (C) 1994-1997, Thomas G. Lane.
   5  * Modified 2015 by Guido Vollbeding.
   6  * This file is part of the Independent JPEG Group's software.
   7  * For conditions of distribution and use, see the accompanying README file.
   8  *
   9  * This file contains a very simple stand-alone application that inserts
  10  * user-supplied text as a COM (comment) marker in a JFIF file.
  11  * This may be useful as an example of the minimum logic needed to parse
  12  * JPEG markers.
  13  */
  14
  15 #define JPEG_CJPEG_DJPEG        /* to get the command-line config symbols */
  16 #include "jinclude.h"           /* get auto-config symbols, <stdio.h> */
  17
  18 #ifndef HAVE_STDLIB_H           /* <stdlib.h> should declare malloc() */
  19 extern void * malloc ();
  20 #endif
  21 #include <ctype.h>              /* to declare isupper(), tolower() */
  22 #ifdef USE_SETMODE
  23 #include <fcntl.h>              /* to declare setmode()'s parameter macros */
  24 /* If you have setmode() but not <io.h>, just delete this line: */
  25 #include <io.h>                 /* to declare setmode() */
  26 #endif
  27
  28 #ifdef USE_CCOMMAND             /* command-line reader for Macintosh */
  29 #ifdef __MWERKS__
  30 #include <SIOUX.h>              /* Metrowerks needs this */
  31 #include <console.h>            /* ... and this */
  32 #endif
  33 #ifdef THINK_C
  34 #include <console.h>            /* Think declares it here */
  35 #endif
  36 #endif
  37
  38 #ifdef DONT_USE_B_MODE          /* define mode parameters for fopen() */
  39 #define READ_BINARY     "r"
  40 #define WRITE_BINARY    "w"
  41 #else
  42 #ifdef VMS                      /* VMS is very nonstandard */
  43 #define READ_BINARY     "rb", "ctx=stm"
  44 #define WRITE_BINARY    "wb", "ctx=stm"
  45 #else                           /* standard ANSI-compliant case */
  46 #define READ_BINARY     "rb"
  47 #define WRITE_BINARY    "wb"
  48 #endif
  49 #endif
  50
  51 #ifndef EXIT_FAILURE            /* define exit() codes if not provided */
  52 #define EXIT_FAILURE  1
  53 #endif
  54 #ifndef EXIT_SUCCESS
  55 #ifdef VMS
  56 #define EXIT_SUCCESS  1         /* VMS is very nonstandard */
  57 #else
  58 #define EXIT_SUCCESS  0
  59 #endif
  60 #endif
  61
  62 /* Reduce this value if your malloc() can't allocate blocks up to 64K.
  63  * On DOS, compiling in large model is usually a better solution.
  64  */
  65
  66 #ifndef MAX_COM_LENGTH
  67 #define MAX_COM_LENGTH 65000L   /* must be <= 65533 in any case */
  68 #endif
  69
  70
  71 /*
  72  * These macros are used to read the input file and write the output file.
  73  * To reuse this code in another application, you might need to change these.
  74  */
  75
  76 static FILE * infile;           /* input JPEG file */
  77
  78 /* Return next input byte, or EOF if no more */
  79 #define NEXTBYTE()  getc(infile)
  80
  81 static FILE * outfile;          /* output JPEG file */
  82
  83 /* Emit an output byte */
  84 #define PUTBYTE(x)  putc((x), outfile)
  85
  86
  87 /* Error exit handler */
  88 #define ERREXIT(msg)  (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE))
  89
  90
  91 /* Read one byte, testing for EOF */
  92 static int
  93 read_1_byte (void)
  94 {
  95   int c;
  96
  97   c = NEXTBYTE();
  98   if (c == EOF)
  99     ERREXIT("Premature EOF in JPEG file");
 100   return c;
 101 }
 102
 103 /* Read 2 bytes, convert to unsigned int */
 104 /* All 2-byte quantities in JPEG markers are MSB first */
 105 static unsigned int
 106 read_2_bytes (void)
 107 {
 108   int c1, c2;
 109
 110   c1 = NEXTBYTE();
 111   if (c1 == EOF)
 112     ERREXIT("Premature EOF in JPEG file");
 113   c2 = NEXTBYTE();
 114   if (c2 == EOF)
 115     ERREXIT("Premature EOF in JPEG file");
 116   return (((unsigned int) c1) << 8) + ((unsigned int) c2);
 117 }
 118
 119
 120 /* Routines to write data to output file */
 121
 122 static void
 123 write_1_byte (int c)
 124 {
 125   PUTBYTE(c);
 126 }
 127
 128 static void
 129 write_2_bytes (unsigned int val)
 130 {
 131   PUTBYTE((val >> 8) & 0xFF);
 132   PUTBYTE(val & 0xFF);
 133 }
 134
 135 static void
 136 write_marker (int marker)
 137 {
 138   PUTBYTE(0xFF);
 139   PUTBYTE(marker);
 140 }
 141
 142 static void
 143 copy_rest_of_file (void)
 144 {
 145   int c;
 146
 147   while ((c = NEXTBYTE()) != EOF)
 148     PUTBYTE(c);
 149 }
 150
 151
 152 /*
 153  * JPEG markers consist of one or more 0xFF bytes, followed by a marker
 154  * code byte (which is not an FF).  Here are the marker codes of interest
 155  * in this program.  (See jdmarker.c for a more complete list.)
 156  */
 157
 158 #define M_SOF0  0xC0            /* Start Of Frame N */
 159 #define M_SOF1  0xC1            /* N indicates which compression process */
 160 #define M_SOF2  0xC2            /* Only SOF0-SOF2 are now in common use */
 161 #define M_SOF3  0xC3
 162 #define M_SOF5  0xC5            /* NB: codes C4 and CC are NOT SOF markers */
 163 #define M_SOF6  0xC6
 164 #define M_SOF7  0xC7
 165 #define M_SOF9  0xC9
 166 #define M_SOF10 0xCA
 167 #define M_SOF11 0xCB
 168 #define M_SOF13 0xCD
 169 #define M_SOF14 0xCE
 170 #define M_SOF15 0xCF
 171 #define M_SOI   0xD8            /* Start Of Image (beginning of datastream) */
 172 #define M_EOI   0xD9            /* End Of Image (end of datastream) */
 173 #define M_SOS   0xDA            /* Start Of Scan (begins compressed data) */
 174 #define M_COM   0xFE            /* COMment */
 175
 176
 177 /*
 178  * Find the next JPEG marker and return its marker code.
 179  * We expect at least one FF byte, possibly more if the compressor used FFs
 180  * to pad the file.  (Padding FFs will NOT be replicated in the output file.)
 181  * There could also be non-FF garbage between markers.  The treatment of such
 182  * garbage is unspecified; we choose to skip over it but emit a warning msg.
 183  * NB: this routine must not be used after seeing SOS marker, since it will
 184  * not deal correctly with FF/00 sequences in the compressed image data...
 185  */
 186
 187 static int
 188 next_marker (void)
 189 {
 190   int c;
 191   int discarded_bytes = 0;
 192
 193   /* Find 0xFF byte; count and skip any non-FFs. */
 194   c = read_1_byte();
 195   while (c != 0xFF) {
 196     discarded_bytes++;
 197     c = read_1_byte();
 198   }
 199   /* Get marker code byte, swallowing any duplicate FF bytes.  Extra FFs
 200    * are legal as pad bytes, so don't count them in discarded_bytes.
 201    */
 202   do {
 203     c = read_1_byte();
 204   } while (c == 0xFF);
 205
 206   if (discarded_bytes != 0) {
 207     fprintf(stderr, "Warning: garbage data found in JPEG file\n");
 208   }
 209
 210   return c;
 211 }
 212
 213
 214 /*
 215  * Read the initial marker, which should be SOI.
 216  * For a JFIF file, the first two bytes of the file should be literally
 217  * 0xFF M_SOI.  To be more general, we could use next_marker, but if the
 218  * input file weren't actually JPEG at all, next_marker might read the whole
 219  * file and then return a misleading error message...
 220  */
 221
 222 static int
 223 first_marker (void)
 224 {
 225   int c1, c2;
 226
 227   c1 = NEXTBYTE();
 228   c2 = NEXTBYTE();
 229   if (c1 != 0xFF || c2 != M_SOI)
 230     ERREXIT("Not a JPEG file");
 231   return c2;
 232 }
 233
 234
 235 /*
 236  * Most types of marker are followed by a variable-length parameter segment.
 237  * This routine skips over the parameters for any marker we don't otherwise
 238  * want to process.
 239  * Note that we MUST skip the parameter segment explicitly in order not to
 240  * be fooled by 0xFF bytes that might appear within the parameter segment;
 241  * such bytes do NOT introduce new markers.
 242  */
 243
 244 static void
 245 copy_variable (void)
 246 /* Copy an unknown or uninteresting variable-length marker */
 247 {
 248   unsigned int length;
 249
 250   /* Get the marker parameter length count */
 251   length = read_2_bytes();
 252   write_2_bytes(length);
 253   /* Length includes itself, so must be at least 2 */
 254   if (length < 2)
 255     ERREXIT("Erroneous JPEG marker length");
 256   length -= 2;
 257   /* Skip over the remaining bytes */
 258   while (length > 0) {
 259     write_1_byte(read_1_byte());
 260     length--;
 261   }
 262 }
 263
 264 static void
 265 skip_variable (void)
 266 /* Skip over an unknown or uninteresting variable-length marker */
 267 {
 268   unsigned int length;
 269
 270   /* Get the marker parameter length count */
 271   length = read_2_bytes();
 272   /* Length includes itself, so must be at least 2 */
 273   if (length < 2)
 274     ERREXIT("Erroneous JPEG marker length");
 275   length -= 2;
 276   /* Skip over the remaining bytes */
 277   while (length > 0) {
 278     (void) read_1_byte();
 279     length--;
 280   }
 281 }
 282
 283
 284 /*
 285  * Parse the marker stream until SOFn or EOI is seen;
 286  * copy data to output, but discard COM markers unless keep_COM is true.
 287  */
 288
 289 static int
 290 scan_JPEG_header (int keep_COM)
 291 {
 292   int marker;
 293
 294   /* Expect SOI at start of file */
 295   if (first_marker() != M_SOI)
 296     ERREXIT("Expected SOI marker first");
 297   write_marker(M_SOI);
 298
 299   /* Scan miscellaneous markers until we reach SOFn. */
 300   for (;;) {
 301     marker = next_marker();
 302     switch (marker) {
 303       /* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be,
 304        * treated as SOFn.  C4 in particular is actually DHT.
 305        */
 306     case M_SOF0:                /* Baseline */
 307     case M_SOF1:                /* Extended sequential, Huffman */
 308     case M_SOF2:                /* Progressive, Huffman */
 309     case M_SOF3:                /* Lossless, Huffman */
 310     case M_SOF5:                /* Differential sequential, Huffman */
 311     case M_SOF6:                /* Differential progressive, Huffman */
 312     case M_SOF7:                /* Differential lossless, Huffman */
 313     case M_SOF9:                /* Extended sequential, arithmetic */
 314     case M_SOF10:               /* Progressive, arithmetic */
 315     case M_SOF11:               /* Lossless, arithmetic */
 316     case M_SOF13:               /* Differential sequential, arithmetic */
 317     case M_SOF14:               /* Differential progressive, arithmetic */
 318     case M_SOF15:               /* Differential lossless, arithmetic */
 319       return marker;
 320
 321     case M_SOS:                 /* should not see compressed data before SOF */
 322       ERREXIT("SOS without prior SOFn");
 323       break;
 324
 325     case M_EOI:                 /* in case it's a tables-only JPEG stream */
 326       return marker;
 327
 328     case M_COM:                 /* Existing COM: conditionally discard */
 329       if (keep_COM) {
 330         write_marker(marker);
 331         copy_variable();
 332       } else {
 333         skip_variable();
 334       }
 335       break;
 336
 337     default:                    /* Anything else just gets copied */
 338       write_marker(marker);
 339       copy_variable();          /* we assume it has a parameter count... */
 340       break;
 341     }
 342   } /* end loop */
 343 }
 344
 345
 346 /* Command line parsing code */
 347
 348 static const char * progname;   /* program name for error messages */
 349
 350
 351 static void
 352 usage (void)
 353 /* complain about bad command line */
 354 {
 355   fprintf(stderr, "wrjpgcom inserts a textual comment in a JPEG file.\n");
 356   fprintf(stderr, "You can add to or replace any existing comment(s).\n");
 357
 358   fprintf(stderr, "Usage: %s [switches] ", progname);
 359 #ifdef TWO_FILE_COMMANDLINE
 360   fprintf(stderr, "inputfile outputfile\n");
 361 #else
 362   fprintf(stderr, "[inputfile]\n");
 363 #endif
 364
 365   fprintf(stderr, "Switches (names may be abbreviated):\n");
 366   fprintf(stderr, "  -replace         Delete any existing comments\n");
 367   fprintf(stderr, "  -comment \"text\"  Insert comment with given text\n");
 368   fprintf(stderr, "  -cfile name      Read comment from named file\n");
 369   fprintf(stderr, "Notice that you must put quotes around the comment text\n");
 370   fprintf(stderr, "when you use -comment.\n");
 371   fprintf(stderr, "If you do not give either -comment or -cfile on the command line,\n");
 372   fprintf(stderr, "then the comment text is read from standard input.\n");
 373   fprintf(stderr, "It can be multiple lines, up to %u characters total.\n",
 374           (unsigned int) MAX_COM_LENGTH);
 375 #ifndef TWO_FILE_COMMANDLINE
 376   fprintf(stderr, "You must specify an input JPEG file name when supplying\n");
 377   fprintf(stderr, "comment text from standard input.\n");
 378 #endif
 379
 380   exit(EXIT_FAILURE);
 381 }
 382
 383
 384 static int
 385 keymatch (char * arg, const char * keyword, int minchars)
 386 /* Case-insensitive matching of (possibly abbreviated) keyword switches. */
 387 /* keyword is the constant keyword (must be lower case already), */
 388 /* minchars is length of minimum legal abbreviation. */
 389 {
 390   register int ca, ck;
 391   register int nmatched = 0;
 392
 393   while ((ca = *arg++) != '\0') {
 394     if ((ck = *keyword++) == '\0')
 395       return 0;                 /* arg longer than keyword, no good */
 396     if (isupper(ca))            /* force arg to lcase (assume ck is already) */
 397       ca = tolower(ca);
 398     if (ca != ck)
 399       return 0;                 /* no good */
 400     nmatched++;                 /* count matched characters */
 401   }
 402   /* reached end of argument; fail if it's too short for unique abbrev */
 403   if (nmatched < minchars)
 404     return 0;
 405   return 1;                     /* A-OK */
 406 }
 407
 408
 409 /*
 410  * The main program.
 411  */
 412
 413 int
 414 main (int argc, char **argv)
 415 {
 416   int argn;
 417   char * arg;
 418   int keep_COM = 1;
 419   char * comment_arg = NULL;
 420   FILE * comment_file = NULL;
 421   unsigned int comment_length = 0;
 422   int marker;
 423
 424   /* On Mac, fetch a command line. */
 425 #ifdef USE_CCOMMAND
 426   argc = ccommand(&argv);
 427 #endif
 428
 429   progname = argv[0];
 430   if (progname == NULL || progname[0] == 0)
 431     progname = "wrjpgcom";      /* in case C library doesn't provide it */
 432
 433   /* Parse switches, if any */
 434   for (argn = 1; argn < argc; argn++) {
 435     arg = argv[argn];
 436     if (arg[0] != '-')
 437       break;                    /* not switch, must be file name */
 438     arg++;                      /* advance over '-' */
 439     if (keymatch(arg, "replace", 1)) {
 440       keep_COM = 0;
 441     } else if (keymatch(arg, "cfile", 2)) {
 442       if (++argn >= argc) usage();
 443       if ((comment_file = fopen(argv[argn], "r")) == NULL) {
 444         fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
 445         exit(EXIT_FAILURE);
 446       }
 447     } else if (keymatch(arg, "comment", 1)) {
 448       if (++argn >= argc) usage();
 449       comment_arg = argv[argn];
 450       /* If the comment text starts with '"', then we are probably running
 451        * under MS-DOG and must parse out the quoted string ourselves.  Sigh.
 452        */
 453       if (comment_arg[0] == '"') {
 454         comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
 455         if (comment_arg == NULL)
 456           ERREXIT("Insufficient memory");
 457         if (strlen(argv[argn]+1) >= (size_t) MAX_COM_LENGTH) {
 458           fprintf(stderr, "Comment text may not exceed %u bytes\n",
 459                   (unsigned int) MAX_COM_LENGTH);
 460           exit(EXIT_FAILURE);
 461         }
 462         strcpy(comment_arg, argv[argn]+1);
 463         for (;;) {
 464           comment_length = (unsigned int) strlen(comment_arg);
 465           if (comment_length > 0 && comment_arg[comment_length-1] == '"') {
 466             comment_arg[comment_length-1] = '\0'; /* zap terminating quote */
 467             break;
 468           }
 469           if (++argn >= argc)
 470             ERREXIT("Missing ending quote mark");
 471           if (strlen(comment_arg) + 1 + strlen(argv[argn]) >=
 472               (size_t) MAX_COM_LENGTH) {
 473             fprintf(stderr, "Comment text may not exceed %u bytes\n",
 474                     (unsigned int) MAX_COM_LENGTH);
 475             exit(EXIT_FAILURE);
 476           }
 477           strcat(comment_arg, " ");
 478           strcat(comment_arg, argv[argn]);
 479         }
 480       } else if (strlen(comment_arg) >= (size_t) MAX_COM_LENGTH) {
 481         fprintf(stderr, "Comment text may not exceed %u bytes\n",
 482                 (unsigned int) MAX_COM_LENGTH);
 483         exit(EXIT_FAILURE);
 484       }
 485       comment_length = (unsigned int) strlen(comment_arg);
 486     } else
 487       usage();
 488   }
 489
 490   /* Cannot use both -comment and -cfile. */
 491   if (comment_arg != NULL && comment_file != NULL)
 492     usage();
 493   /* If there is neither -comment nor -cfile, we will read the comment text
 494    * from stdin; in this case there MUST be an input JPEG file name.
 495    */
 496   if (comment_arg == NULL && comment_file == NULL && argn >= argc)
 497     usage();
 498
 499   /* Open the input file. */
 500   if (argn < argc) {
 501     if ((infile = fopen(argv[argn], READ_BINARY)) == NULL) {
 502       fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
 503       exit(EXIT_FAILURE);
 504     }
 505   } else {
 506     /* default input file is stdin */
 507 #ifdef USE_SETMODE              /* need to hack file mode? */
 508     setmode(fileno(stdin), O_BINARY);
 509 #endif
 510 #ifdef USE_FDOPEN               /* need to re-open in binary mode? */
 511     if ((infile = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
 512       fprintf(stderr, "%s: can't open stdin\n", progname);
 513       exit(EXIT_FAILURE);
 514     }
 515 #else
 516     infile = stdin;
 517 #endif
 518   }
 519
 520   /* Open the output file. */
 521 #ifdef TWO_FILE_COMMANDLINE
 522   /* Must have explicit output file name */
 523   if (argn != argc-2) {
 524     fprintf(stderr, "%s: must name one input and one output file\n",
 525             progname);
 526     usage();
 527   }
 528   if ((outfile = fopen(argv[argn+1], WRITE_BINARY)) == NULL) {
 529     fprintf(stderr, "%s: can't open %s\n", progname, argv[argn+1]);
 530     exit(EXIT_FAILURE);
 531   }
 532 #else
 533   /* Unix style: expect zero or one file name */
 534   if (argn < argc-1) {
 535     fprintf(stderr, "%s: only one input file\n", progname);
 536     usage();
 537   }
 538   /* default output file is stdout */
 539 #ifdef USE_SETMODE              /* need to hack file mode? */
 540   setmode(fileno(stdout), O_BINARY);
 541 #endif
 542 #ifdef USE_FDOPEN               /* need to re-open in binary mode? */
 543   if ((outfile = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
 544     fprintf(stderr, "%s: can't open stdout\n", progname);
 545     exit(EXIT_FAILURE);
 546   }
 547 #else
 548   outfile = stdout;
 549 #endif
 550 #endif /* TWO_FILE_COMMANDLINE */
 551
 552   /* Collect comment text from comment_file or stdin, if necessary */
 553   if (comment_arg == NULL) {
 554     FILE * src_file;
 555     int c;
 556
 557     comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
 558     if (comment_arg == NULL)
 559       ERREXIT("Insufficient memory");
 560     comment_length = 0;
 561     src_file = (comment_file != NULL ? comment_file : stdin);
 562     while ((c = getc(src_file)) != EOF) {
 563       if (comment_length >= (unsigned int) MAX_COM_LENGTH) {
 564         fprintf(stderr, "Comment text may not exceed %u bytes\n",
 565                 (unsigned int) MAX_COM_LENGTH);
 566         exit(EXIT_FAILURE);
 567       }
 568       comment_arg[comment_length++] = (char) c;
 569     }
 570     if (comment_file != NULL)
 571       fclose(comment_file);
 572   }
 573
 574   /* Copy JPEG headers until SOFn marker;
 575    * we will insert the new comment marker just before SOFn.
 576    * This (a) causes the new comment to appear after, rather than before,
 577    * existing comments; and (b) ensures that comments come after any JFIF
 578    * or JFXX markers, as required by the JFIF specification.
 579    */
 580   marker = scan_JPEG_header(keep_COM);
 581   /* Insert the new COM marker, but only if nonempty text has been supplied */
 582   if (comment_length > 0) {
 583     write_marker(M_COM);
 584     write_2_bytes(comment_length + 2);
 585     while (comment_length > 0) {
 586       write_1_byte(*comment_arg++);
 587       comment_length--;
 588     }
 589   }
 590   /* Duplicate the remainder of the source file.
 591    * Note that any COM markers occuring after SOF will not be touched.
 592    */
 593   write_marker(marker);
 594   copy_rest_of_file();
 595
 596   /* All done. */
 597   exit(EXIT_SUCCESS);
 598   return 0;                     /* suppress no-return-value warnings */
 599 }