4 * This file was part of the Independent JPEG Group's software:
5 * Copyright (C) 1994-1997, Thomas G. Lane.
6 * libjpeg-turbo Modifications:
7 * Copyright (C) 2014, D. R. Commander.
8 * For conditions of distribution and use, see the accompanying README.ijg
11 * This file contains a very simple stand-alone application that inserts
12 * user-supplied text as a COM (comment) marker in a JFIF file.
13 * This may be useful as an example of the minimum logic needed to parse
17 #define JPEG_CJPEG_DJPEG /* to get the command-line config symbols */
18 #include "jinclude.h" /* get auto-config symbols, <stdio.h> */
20 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc() */
21 extern void *malloc ();
23 #include <ctype.h> /* to declare isupper(), tolower() */
25 #include <fcntl.h> /* to declare setmode()'s parameter macros */
26 /* If you have setmode() but not <io.h>, just delete this line: */
27 #include <io.h> /* to declare setmode() */
30 #ifdef USE_CCOMMAND /* command-line reader for Macintosh */
32 #include <SIOUX.h> /* Metrowerks needs this */
33 #include <console.h> /* ... and this */
36 #include <console.h> /* Think declares it here */
40 #ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
41 #define READ_BINARY "r"
42 #define WRITE_BINARY "w"
44 #define READ_BINARY "rb"
45 #define WRITE_BINARY "wb"
48 #ifndef EXIT_FAILURE /* define exit() codes if not provided */
49 #define EXIT_FAILURE 1
52 #define EXIT_SUCCESS 0
55 /* Reduce this value if your malloc() can't allocate blocks up to 64K.
56 * On DOS, compiling in large model is usually a better solution.
59 #ifndef MAX_COM_LENGTH
60 #define MAX_COM_LENGTH 65000L /* must be <= 65533 in any case */
65 * These macros are used to read the input file and write the output file.
66 * To reuse this code in another application, you might need to change these.
69 static FILE *infile; /* input JPEG file */
71 /* Return next input byte, or EOF if no more */
72 #define NEXTBYTE() getc(infile)
74 static FILE *outfile; /* output JPEG file */
76 /* Emit an output byte */
77 #define PUTBYTE(x) putc((x), outfile)
80 /* Error exit handler */
81 #define ERREXIT(msg) (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE))
84 /* Read one byte, testing for EOF */
92 ERREXIT("Premature EOF in JPEG file");
96 /* Read 2 bytes, convert to unsigned int */
97 /* All 2-byte quantities in JPEG markers are MSB first */
105 ERREXIT("Premature EOF in JPEG file");
108 ERREXIT("Premature EOF in JPEG file");
109 return (((unsigned int) c1) << 8) + ((unsigned int) c2);
113 /* Routines to write data to output file */
122 write_2_bytes (unsigned int val)
124 PUTBYTE((val >> 8) & 0xFF);
129 write_marker (int marker)
136 copy_rest_of_file (void)
140 while ((c = NEXTBYTE()) != EOF)
146 * JPEG markers consist of one or more 0xFF bytes, followed by a marker
147 * code byte (which is not an FF). Here are the marker codes of interest
148 * in this program. (See jdmarker.c for a more complete list.)
151 #define M_SOF0 0xC0 /* Start Of Frame N */
152 #define M_SOF1 0xC1 /* N indicates which compression process */
153 #define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */
155 #define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */
164 #define M_SOI 0xD8 /* Start Of Image (beginning of datastream) */
165 #define M_EOI 0xD9 /* End Of Image (end of datastream) */
166 #define M_SOS 0xDA /* Start Of Scan (begins compressed data) */
167 #define M_COM 0xFE /* COMment */
171 * Find the next JPEG marker and return its marker code.
172 * We expect at least one FF byte, possibly more if the compressor used FFs
173 * to pad the file. (Padding FFs will NOT be replicated in the output file.)
174 * There could also be non-FF garbage between markers. The treatment of such
175 * garbage is unspecified; we choose to skip over it but emit a warning msg.
176 * NB: this routine must not be used after seeing SOS marker, since it will
177 * not deal correctly with FF/00 sequences in the compressed image data...
184 int discarded_bytes = 0;
186 /* Find 0xFF byte; count and skip any non-FFs. */
192 /* Get marker code byte, swallowing any duplicate FF bytes. Extra FFs
193 * are legal as pad bytes, so don't count them in discarded_bytes.
199 if (discarded_bytes != 0) {
200 fprintf(stderr, "Warning: garbage data found in JPEG file\n");
208 * Read the initial marker, which should be SOI.
209 * For a JFIF file, the first two bytes of the file should be literally
210 * 0xFF M_SOI. To be more general, we could use next_marker, but if the
211 * input file weren't actually JPEG at all, next_marker might read the whole
212 * file and then return a misleading error message...
222 if (c1 != 0xFF || c2 != M_SOI)
223 ERREXIT("Not a JPEG file");
229 * Most types of marker are followed by a variable-length parameter segment.
230 * This routine skips over the parameters for any marker we don't otherwise
232 * Note that we MUST skip the parameter segment explicitly in order not to
233 * be fooled by 0xFF bytes that might appear within the parameter segment;
234 * such bytes do NOT introduce new markers.
239 /* Copy an unknown or uninteresting variable-length marker */
243 /* Get the marker parameter length count */
244 length = read_2_bytes();
245 write_2_bytes(length);
246 /* Length includes itself, so must be at least 2 */
248 ERREXIT("Erroneous JPEG marker length");
250 /* Copy the remaining bytes */
252 write_1_byte(read_1_byte());
259 /* Skip over an unknown or uninteresting variable-length marker */
263 /* Get the marker parameter length count */
264 length = read_2_bytes();
265 /* Length includes itself, so must be at least 2 */
267 ERREXIT("Erroneous JPEG marker length");
269 /* Skip over the remaining bytes */
271 (void) read_1_byte();
278 * Parse the marker stream until SOFn or EOI is seen;
279 * copy data to output, but discard COM markers unless keep_COM is true.
283 scan_JPEG_header (int keep_COM)
287 /* Expect SOI at start of file */
288 if (first_marker() != M_SOI)
289 ERREXIT("Expected SOI marker first");
292 /* Scan miscellaneous markers until we reach SOFn. */
294 marker = next_marker();
296 /* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be,
297 * treated as SOFn. C4 in particular is actually DHT.
299 case M_SOF0: /* Baseline */
300 case M_SOF1: /* Extended sequential, Huffman */
301 case M_SOF2: /* Progressive, Huffman */
302 case M_SOF3: /* Lossless, Huffman */
303 case M_SOF5: /* Differential sequential, Huffman */
304 case M_SOF6: /* Differential progressive, Huffman */
305 case M_SOF7: /* Differential lossless, Huffman */
306 case M_SOF9: /* Extended sequential, arithmetic */
307 case M_SOF10: /* Progressive, arithmetic */
308 case M_SOF11: /* Lossless, arithmetic */
309 case M_SOF13: /* Differential sequential, arithmetic */
310 case M_SOF14: /* Differential progressive, arithmetic */
311 case M_SOF15: /* Differential lossless, arithmetic */
314 case M_SOS: /* should not see compressed data before SOF */
315 ERREXIT("SOS without prior SOFn");
318 case M_EOI: /* in case it's a tables-only JPEG stream */
321 case M_COM: /* Existing COM: conditionally discard */
323 write_marker(marker);
330 default: /* Anything else just gets copied */
331 write_marker(marker);
332 copy_variable(); /* we assume it has a parameter count... */
339 /* Command line parsing code */
341 static const char *progname; /* program name for error messages */
346 /* complain about bad command line */
348 fprintf(stderr, "wrjpgcom inserts a textual comment in a JPEG file.\n");
349 fprintf(stderr, "You can add to or replace any existing comment(s).\n");
351 fprintf(stderr, "Usage: %s [switches] ", progname);
352 #ifdef TWO_FILE_COMMANDLINE
353 fprintf(stderr, "inputfile outputfile\n");
355 fprintf(stderr, "[inputfile]\n");
358 fprintf(stderr, "Switches (names may be abbreviated):\n");
359 fprintf(stderr, " -replace Delete any existing comments\n");
360 fprintf(stderr, " -comment \"text\" Insert comment with given text\n");
361 fprintf(stderr, " -cfile name Read comment from named file\n");
362 fprintf(stderr, "Notice that you must put quotes around the comment text\n");
363 fprintf(stderr, "when you use -comment.\n");
364 fprintf(stderr, "If you do not give either -comment or -cfile on the command line,\n");
365 fprintf(stderr, "then the comment text is read from standard input.\n");
366 fprintf(stderr, "It can be multiple lines, up to %u characters total.\n",
367 (unsigned int) MAX_COM_LENGTH);
368 #ifndef TWO_FILE_COMMANDLINE
369 fprintf(stderr, "You must specify an input JPEG file name when supplying\n");
370 fprintf(stderr, "comment text from standard input.\n");
378 keymatch (char *arg, const char *keyword, int minchars)
379 /* Case-insensitive matching of (possibly abbreviated) keyword switches. */
380 /* keyword is the constant keyword (must be lower case already), */
381 /* minchars is length of minimum legal abbreviation. */
384 register int nmatched = 0;
386 while ((ca = *arg++) != '\0') {
387 if ((ck = *keyword++) == '\0')
388 return 0; /* arg longer than keyword, no good */
389 if (isupper(ca)) /* force arg to lcase (assume ck is already) */
392 return 0; /* no good */
393 nmatched++; /* count matched characters */
395 /* reached end of argument; fail if it's too short for unique abbrev */
396 if (nmatched < minchars)
407 main (int argc, char **argv)
412 char *comment_arg = NULL;
413 FILE *comment_file = NULL;
414 unsigned int comment_length = 0;
417 /* On Mac, fetch a command line. */
419 argc = ccommand(&argv);
423 if (progname == NULL || progname[0] == 0)
424 progname = "wrjpgcom"; /* in case C library doesn't provide it */
426 /* Parse switches, if any */
427 for (argn = 1; argn < argc; argn++) {
430 break; /* not switch, must be file name */
431 arg++; /* advance over '-' */
432 if (keymatch(arg, "replace", 1)) {
434 } else if (keymatch(arg, "cfile", 2)) {
435 if (++argn >= argc) usage();
436 if ((comment_file = fopen(argv[argn], "r")) == NULL) {
437 fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
440 } else if (keymatch(arg, "comment", 1)) {
441 if (++argn >= argc) usage();
442 comment_arg = argv[argn];
443 /* If the comment text starts with '"', then we are probably running
444 * under MS-DOG and must parse out the quoted string ourselves. Sigh.
446 if (comment_arg[0] == '"') {
447 comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
448 if (comment_arg == NULL)
449 ERREXIT("Insufficient memory");
450 if (strlen(argv[argn]) + 2 >= (size_t) MAX_COM_LENGTH) {
451 fprintf(stderr, "Comment text may not exceed %u bytes\n",
452 (unsigned int) MAX_COM_LENGTH);
455 strcpy(comment_arg, argv[argn]+1);
457 comment_length = (unsigned int) strlen(comment_arg);
458 if (comment_length > 0 && comment_arg[comment_length-1] == '"') {
459 comment_arg[comment_length-1] = '\0'; /* zap terminating quote */
463 ERREXIT("Missing ending quote mark");
464 if (strlen(comment_arg) + strlen(argv[argn]) + 2 >=
465 (size_t) MAX_COM_LENGTH) {
466 fprintf(stderr, "Comment text may not exceed %u bytes\n",
467 (unsigned int) MAX_COM_LENGTH);
470 strcat(comment_arg, " ");
471 strcat(comment_arg, argv[argn]);
473 } else if (strlen(argv[argn]) >= (size_t) MAX_COM_LENGTH) {
474 fprintf(stderr, "Comment text may not exceed %u bytes\n",
475 (unsigned int) MAX_COM_LENGTH);
478 comment_length = (unsigned int) strlen(comment_arg);
483 /* Cannot use both -comment and -cfile. */
484 if (comment_arg != NULL && comment_file != NULL)
486 /* If there is neither -comment nor -cfile, we will read the comment text
487 * from stdin; in this case there MUST be an input JPEG file name.
489 if (comment_arg == NULL && comment_file == NULL && argn >= argc)
492 /* Open the input file. */
494 if ((infile = fopen(argv[argn], READ_BINARY)) == NULL) {
495 fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
499 /* default input file is stdin */
500 #ifdef USE_SETMODE /* need to hack file mode? */
501 setmode(fileno(stdin), O_BINARY);
503 #ifdef USE_FDOPEN /* need to re-open in binary mode? */
504 if ((infile = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
505 fprintf(stderr, "%s: can't open stdin\n", progname);
513 /* Open the output file. */
514 #ifdef TWO_FILE_COMMANDLINE
515 /* Must have explicit output file name */
516 if (argn != argc-2) {
517 fprintf(stderr, "%s: must name one input and one output file\n",
521 if ((outfile = fopen(argv[argn+1], WRITE_BINARY)) == NULL) {
522 fprintf(stderr, "%s: can't open %s\n", progname, argv[argn+1]);
526 /* Unix style: expect zero or one file name */
528 fprintf(stderr, "%s: only one input file\n", progname);
531 /* default output file is stdout */
532 #ifdef USE_SETMODE /* need to hack file mode? */
533 setmode(fileno(stdout), O_BINARY);
535 #ifdef USE_FDOPEN /* need to re-open in binary mode? */
536 if ((outfile = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
537 fprintf(stderr, "%s: can't open stdout\n", progname);
543 #endif /* TWO_FILE_COMMANDLINE */
545 /* Collect comment text from comment_file or stdin, if necessary */
546 if (comment_arg == NULL) {
550 comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
551 if (comment_arg == NULL)
552 ERREXIT("Insufficient memory");
554 src_file = (comment_file != NULL ? comment_file : stdin);
555 while ((c = getc(src_file)) != EOF) {
556 if (comment_length >= (unsigned int) MAX_COM_LENGTH) {
557 fprintf(stderr, "Comment text may not exceed %u bytes\n",
558 (unsigned int) MAX_COM_LENGTH);
561 comment_arg[comment_length++] = (char) c;
563 if (comment_file != NULL)
564 fclose(comment_file);
567 /* Copy JPEG headers until SOFn marker;
568 * we will insert the new comment marker just before SOFn.
569 * This (a) causes the new comment to appear after, rather than before,
570 * existing comments; and (b) ensures that comments come after any JFIF
571 * or JFXX markers, as required by the JFIF specification.
573 marker = scan_JPEG_header(keep_COM);
574 /* Insert the new COM marker, but only if nonempty text has been supplied */
575 if (comment_length > 0) {
577 write_2_bytes(comment_length + 2);
578 while (comment_length > 0) {
579 write_1_byte(*comment_arg++);
583 /* Duplicate the remainder of the source file.
584 * Note that any COM markers occuring after SOF will not be touched.
586 write_marker(marker);
591 return 0; /* suppress no-return-value warnings */