Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * wrjpgcom.c |
| 3 | * |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 4 | * Copyright (C) 1994-1997, Thomas G. Lane. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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__ |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 29 | #include <SIOUX.h> /* Metrowerks needs this */ |
| 30 | #include <console.h> /* ... and this */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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 |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 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 */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 45 | #define READ_BINARY "rb" |
| 46 | #define WRITE_BINARY "wb" |
| 47 | #endif |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 48 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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 |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 66 | #define MAX_COM_LENGTH 65000L /* must be <= 65533 in any case */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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 */ |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 159 | #define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 160 | #define M_SOF3 0xC3 |
Thomas G. Lane | a8b67c4 | 1995-03-15 00:00:00 +0000 | [diff] [blame] | 161 | #define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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) { |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 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 | */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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 (;;) { |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 458 | comment_length = (unsigned int) strlen(comment_arg); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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 | } |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 469 | comment_length = (unsigned int) strlen(comment_arg); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 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 | } |