584 lines
16 KiB
C
584 lines
16 KiB
C
/*
|
|
* wrjpgcom.c
|
|
*
|
|
* Copyright (C) 1994-1997, Thomas G. Lane.
|
|
* This file is part of the Independent JPEG Group's software.
|
|
* For conditions of distribution and use, see the accompanying README file.
|
|
*
|
|
* This file contains a very simple stand-alone application that inserts
|
|
* user-supplied text as a COM (comment) marker in a JFIF file.
|
|
* This may be useful as an example of the minimum logic needed to parse
|
|
* JPEG markers.
|
|
*/
|
|
|
|
#define JPEG_CJPEG_DJPEG /* to get the command-line config symbols */
|
|
#include "jinclude.h" /* get auto-config symbols, <stdio.h> */
|
|
|
|
#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc() */
|
|
extern void * malloc ();
|
|
#endif
|
|
#include <ctype.h> /* to declare isupper(), tolower() */
|
|
#ifdef USE_SETMODE
|
|
#include <fcntl.h> /* to declare setmode()'s parameter macros */
|
|
/* If you have setmode() but not <io.h>, just delete this line: */
|
|
#include <io.h> /* to declare setmode() */
|
|
#endif
|
|
|
|
#ifdef USE_CCOMMAND /* command-line reader for Macintosh */
|
|
#ifdef __MWERKS__
|
|
#include <SIOUX.h> /* Metrowerks needs this */
|
|
#include <console.h> /* ... and this */
|
|
#endif
|
|
#ifdef THINK_C
|
|
#include <console.h> /* Think declares it here */
|
|
#endif
|
|
#endif
|
|
|
|
#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
|
|
#define READ_BINARY "r"
|
|
#define WRITE_BINARY "w"
|
|
#else
|
|
#ifdef VMS /* VMS is very nonstandard */
|
|
#define READ_BINARY "rb", "ctx=stm"
|
|
#define WRITE_BINARY "wb", "ctx=stm"
|
|
#else /* standard ANSI-compliant case */
|
|
#define READ_BINARY "rb"
|
|
#define WRITE_BINARY "wb"
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef EXIT_FAILURE /* define exit() codes if not provided */
|
|
#define EXIT_FAILURE 1
|
|
#endif
|
|
#ifndef EXIT_SUCCESS
|
|
#ifdef VMS
|
|
#define EXIT_SUCCESS 1 /* VMS is very nonstandard */
|
|
#else
|
|
#define EXIT_SUCCESS 0
|
|
#endif
|
|
#endif
|
|
|
|
/* Reduce this value if your malloc() can't allocate blocks up to 64K.
|
|
* On DOS, compiling in large model is usually a better solution.
|
|
*/
|
|
|
|
#ifndef MAX_COM_LENGTH
|
|
#define MAX_COM_LENGTH 65000L /* must be <= 65533 in any case */
|
|
#endif
|
|
|
|
|
|
/*
|
|
* These macros are used to read the input file and write the output file.
|
|
* To reuse this code in another application, you might need to change these.
|
|
*/
|
|
|
|
static FILE * infile; /* input JPEG file */
|
|
|
|
/* Return next input byte, or EOF if no more */
|
|
#define NEXTBYTE() getc(infile)
|
|
|
|
static FILE * outfile; /* output JPEG file */
|
|
|
|
/* Emit an output byte */
|
|
#define PUTBYTE(x) putc((x), outfile)
|
|
|
|
|
|
/* Error exit handler */
|
|
#define ERREXIT(msg) (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE))
|
|
|
|
|
|
/* Read one byte, testing for EOF */
|
|
static int
|
|
read_1_byte (void)
|
|
{
|
|
int c;
|
|
|
|
c = NEXTBYTE();
|
|
if (c == EOF)
|
|
ERREXIT("Premature EOF in JPEG file");
|
|
return c;
|
|
}
|
|
|
|
/* Read 2 bytes, convert to unsigned int */
|
|
/* All 2-byte quantities in JPEG markers are MSB first */
|
|
static unsigned int
|
|
read_2_bytes (void)
|
|
{
|
|
int c1, c2;
|
|
|
|
c1 = NEXTBYTE();
|
|
if (c1 == EOF)
|
|
ERREXIT("Premature EOF in JPEG file");
|
|
c2 = NEXTBYTE();
|
|
if (c2 == EOF)
|
|
ERREXIT("Premature EOF in JPEG file");
|
|
return (((unsigned int) c1) << 8) + ((unsigned int) c2);
|
|
}
|
|
|
|
|
|
/* Routines to write data to output file */
|
|
|
|
static void
|
|
write_1_byte (int c)
|
|
{
|
|
PUTBYTE(c);
|
|
}
|
|
|
|
static void
|
|
write_2_bytes (unsigned int val)
|
|
{
|
|
PUTBYTE((val >> 8) & 0xFF);
|
|
PUTBYTE(val & 0xFF);
|
|
}
|
|
|
|
static void
|
|
write_marker (int marker)
|
|
{
|
|
PUTBYTE(0xFF);
|
|
PUTBYTE(marker);
|
|
}
|
|
|
|
static void
|
|
copy_rest_of_file (void)
|
|
{
|
|
int c;
|
|
|
|
while ((c = NEXTBYTE()) != EOF)
|
|
PUTBYTE(c);
|
|
}
|
|
|
|
|
|
/*
|
|
* JPEG markers consist of one or more 0xFF bytes, followed by a marker
|
|
* code byte (which is not an FF). Here are the marker codes of interest
|
|
* in this program. (See jdmarker.c for a more complete list.)
|
|
*/
|
|
|
|
#define M_SOF0 0xC0 /* Start Of Frame N */
|
|
#define M_SOF1 0xC1 /* N indicates which compression process */
|
|
#define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */
|
|
#define M_SOF3 0xC3
|
|
#define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */
|
|
#define M_SOF6 0xC6
|
|
#define M_SOF7 0xC7
|
|
#define M_SOF9 0xC9
|
|
#define M_SOF10 0xCA
|
|
#define M_SOF11 0xCB
|
|
#define M_SOF13 0xCD
|
|
#define M_SOF14 0xCE
|
|
#define M_SOF15 0xCF
|
|
#define M_SOI 0xD8 /* Start Of Image (beginning of datastream) */
|
|
#define M_EOI 0xD9 /* End Of Image (end of datastream) */
|
|
#define M_SOS 0xDA /* Start Of Scan (begins compressed data) */
|
|
#define M_COM 0xFE /* COMment */
|
|
|
|
|
|
/*
|
|
* Find the next JPEG marker and return its marker code.
|
|
* We expect at least one FF byte, possibly more if the compressor used FFs
|
|
* to pad the file. (Padding FFs will NOT be replicated in the output file.)
|
|
* There could also be non-FF garbage between markers. The treatment of such
|
|
* garbage is unspecified; we choose to skip over it but emit a warning msg.
|
|
* NB: this routine must not be used after seeing SOS marker, since it will
|
|
* not deal correctly with FF/00 sequences in the compressed image data...
|
|
*/
|
|
|
|
static int
|
|
next_marker (void)
|
|
{
|
|
int c;
|
|
int discarded_bytes = 0;
|
|
|
|
/* Find 0xFF byte; count and skip any non-FFs. */
|
|
c = read_1_byte();
|
|
while (c != 0xFF) {
|
|
discarded_bytes++;
|
|
c = read_1_byte();
|
|
}
|
|
/* Get marker code byte, swallowing any duplicate FF bytes. Extra FFs
|
|
* are legal as pad bytes, so don't count them in discarded_bytes.
|
|
*/
|
|
do {
|
|
c = read_1_byte();
|
|
} while (c == 0xFF);
|
|
|
|
if (discarded_bytes != 0) {
|
|
fprintf(stderr, "Warning: garbage data found in JPEG file\n");
|
|
}
|
|
|
|
return c;
|
|
}
|
|
|
|
|
|
/*
|
|
* Read the initial marker, which should be SOI.
|
|
* For a JFIF file, the first two bytes of the file should be literally
|
|
* 0xFF M_SOI. To be more general, we could use next_marker, but if the
|
|
* input file weren't actually JPEG at all, next_marker might read the whole
|
|
* file and then return a misleading error message...
|
|
*/
|
|
|
|
static int
|
|
first_marker (void)
|
|
{
|
|
int c1, c2;
|
|
|
|
c1 = NEXTBYTE();
|
|
c2 = NEXTBYTE();
|
|
if (c1 != 0xFF || c2 != M_SOI)
|
|
ERREXIT("Not a JPEG file");
|
|
return c2;
|
|
}
|
|
|
|
|
|
/*
|
|
* Most types of marker are followed by a variable-length parameter segment.
|
|
* This routine skips over the parameters for any marker we don't otherwise
|
|
* want to process.
|
|
* Note that we MUST skip the parameter segment explicitly in order not to
|
|
* be fooled by 0xFF bytes that might appear within the parameter segment;
|
|
* such bytes do NOT introduce new markers.
|
|
*/
|
|
|
|
static void
|
|
copy_variable (void)
|
|
/* Copy an unknown or uninteresting variable-length marker */
|
|
{
|
|
unsigned int length;
|
|
|
|
/* Get the marker parameter length count */
|
|
length = read_2_bytes();
|
|
write_2_bytes(length);
|
|
/* Length includes itself, so must be at least 2 */
|
|
if (length < 2)
|
|
ERREXIT("Erroneous JPEG marker length");
|
|
length -= 2;
|
|
/* Skip over the remaining bytes */
|
|
while (length > 0) {
|
|
write_1_byte(read_1_byte());
|
|
length--;
|
|
}
|
|
}
|
|
|
|
static void
|
|
skip_variable (void)
|
|
/* Skip over an unknown or uninteresting variable-length marker */
|
|
{
|
|
unsigned int length;
|
|
|
|
/* Get the marker parameter length count */
|
|
length = read_2_bytes();
|
|
/* Length includes itself, so must be at least 2 */
|
|
if (length < 2)
|
|
ERREXIT("Erroneous JPEG marker length");
|
|
length -= 2;
|
|
/* Skip over the remaining bytes */
|
|
while (length > 0) {
|
|
(void) read_1_byte();
|
|
length--;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Parse the marker stream until SOFn or EOI is seen;
|
|
* copy data to output, but discard COM markers unless keep_COM is true.
|
|
*/
|
|
|
|
static int
|
|
scan_JPEG_header (int keep_COM)
|
|
{
|
|
int marker;
|
|
|
|
/* Expect SOI at start of file */
|
|
if (first_marker() != M_SOI)
|
|
ERREXIT("Expected SOI marker first");
|
|
write_marker(M_SOI);
|
|
|
|
/* Scan miscellaneous markers until we reach SOFn. */
|
|
for (;;) {
|
|
marker = next_marker();
|
|
switch (marker) {
|
|
/* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be,
|
|
* treated as SOFn. C4 in particular is actually DHT.
|
|
*/
|
|
case M_SOF0: /* Baseline */
|
|
case M_SOF1: /* Extended sequential, Huffman */
|
|
case M_SOF2: /* Progressive, Huffman */
|
|
case M_SOF3: /* Lossless, Huffman */
|
|
case M_SOF5: /* Differential sequential, Huffman */
|
|
case M_SOF6: /* Differential progressive, Huffman */
|
|
case M_SOF7: /* Differential lossless, Huffman */
|
|
case M_SOF9: /* Extended sequential, arithmetic */
|
|
case M_SOF10: /* Progressive, arithmetic */
|
|
case M_SOF11: /* Lossless, arithmetic */
|
|
case M_SOF13: /* Differential sequential, arithmetic */
|
|
case M_SOF14: /* Differential progressive, arithmetic */
|
|
case M_SOF15: /* Differential lossless, arithmetic */
|
|
return marker;
|
|
|
|
case M_SOS: /* should not see compressed data before SOF */
|
|
ERREXIT("SOS without prior SOFn");
|
|
break;
|
|
|
|
case M_EOI: /* in case it's a tables-only JPEG stream */
|
|
return marker;
|
|
|
|
case M_COM: /* Existing COM: conditionally discard */
|
|
if (keep_COM) {
|
|
write_marker(marker);
|
|
copy_variable();
|
|
} else {
|
|
skip_variable();
|
|
}
|
|
break;
|
|
|
|
default: /* Anything else just gets copied */
|
|
write_marker(marker);
|
|
copy_variable(); /* we assume it has a parameter count... */
|
|
break;
|
|
}
|
|
} /* end loop */
|
|
}
|
|
|
|
|
|
/* Command line parsing code */
|
|
|
|
static const char * progname; /* program name for error messages */
|
|
|
|
|
|
static void
|
|
usage (void)
|
|
/* complain about bad command line */
|
|
{
|
|
fprintf(stderr, "wrjpgcom inserts a textual comment in a JPEG file.\n");
|
|
fprintf(stderr, "You can add to or replace any existing comment(s).\n");
|
|
|
|
fprintf(stderr, "Usage: %s [switches] ", progname);
|
|
#ifdef TWO_FILE_COMMANDLINE
|
|
fprintf(stderr, "inputfile outputfile\n");
|
|
#else
|
|
fprintf(stderr, "[inputfile]\n");
|
|
#endif
|
|
|
|
fprintf(stderr, "Switches (names may be abbreviated):\n");
|
|
fprintf(stderr, " -replace Delete any existing comments\n");
|
|
fprintf(stderr, " -comment \"text\" Insert comment with given text\n");
|
|
fprintf(stderr, " -cfile name Read comment from named file\n");
|
|
fprintf(stderr, "Notice that you must put quotes around the comment text\n");
|
|
fprintf(stderr, "when you use -comment.\n");
|
|
fprintf(stderr, "If you do not give either -comment or -cfile on the command line,\n");
|
|
fprintf(stderr, "then the comment text is read from standard input.\n");
|
|
fprintf(stderr, "It can be multiple lines, up to %u characters total.\n",
|
|
(unsigned int) MAX_COM_LENGTH);
|
|
#ifndef TWO_FILE_COMMANDLINE
|
|
fprintf(stderr, "You must specify an input JPEG file name when supplying\n");
|
|
fprintf(stderr, "comment text from standard input.\n");
|
|
#endif
|
|
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
|
|
static int
|
|
keymatch (char * arg, const char * keyword, int minchars)
|
|
/* Case-insensitive matching of (possibly abbreviated) keyword switches. */
|
|
/* keyword is the constant keyword (must be lower case already), */
|
|
/* minchars is length of minimum legal abbreviation. */
|
|
{
|
|
register int ca, ck;
|
|
register int nmatched = 0;
|
|
|
|
while ((ca = *arg++) != '\0') {
|
|
if ((ck = *keyword++) == '\0')
|
|
return 0; /* arg longer than keyword, no good */
|
|
if (isupper(ca)) /* force arg to lcase (assume ck is already) */
|
|
ca = tolower(ca);
|
|
if (ca != ck)
|
|
return 0; /* no good */
|
|
nmatched++; /* count matched characters */
|
|
}
|
|
/* reached end of argument; fail if it's too short for unique abbrev */
|
|
if (nmatched < minchars)
|
|
return 0;
|
|
return 1; /* A-OK */
|
|
}
|
|
|
|
|
|
/*
|
|
* The main program.
|
|
*/
|
|
|
|
int
|
|
main (int argc, char **argv)
|
|
{
|
|
int argn;
|
|
char * arg;
|
|
int keep_COM = 1;
|
|
char * comment_arg = NULL;
|
|
FILE * comment_file = NULL;
|
|
unsigned int comment_length = 0;
|
|
int marker;
|
|
|
|
/* On Mac, fetch a command line. */
|
|
#ifdef USE_CCOMMAND
|
|
argc = ccommand(&argv);
|
|
#endif
|
|
|
|
progname = argv[0];
|
|
if (progname == NULL || progname[0] == 0)
|
|
progname = "wrjpgcom"; /* in case C library doesn't provide it */
|
|
|
|
/* Parse switches, if any */
|
|
for (argn = 1; argn < argc; argn++) {
|
|
arg = argv[argn];
|
|
if (arg[0] != '-')
|
|
break; /* not switch, must be file name */
|
|
arg++; /* advance over '-' */
|
|
if (keymatch(arg, "replace", 1)) {
|
|
keep_COM = 0;
|
|
} else if (keymatch(arg, "cfile", 2)) {
|
|
if (++argn >= argc) usage();
|
|
if ((comment_file = fopen(argv[argn], "r")) == NULL) {
|
|
fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
} else if (keymatch(arg, "comment", 1)) {
|
|
if (++argn >= argc) usage();
|
|
comment_arg = argv[argn];
|
|
/* If the comment text starts with '"', then we are probably running
|
|
* under MS-DOG and must parse out the quoted string ourselves. Sigh.
|
|
*/
|
|
if (comment_arg[0] == '"') {
|
|
comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
|
|
if (comment_arg == NULL)
|
|
ERREXIT("Insufficient memory");
|
|
strcpy(comment_arg, argv[argn]+1);
|
|
for (;;) {
|
|
comment_length = (unsigned int) strlen(comment_arg);
|
|
if (comment_length > 0 && comment_arg[comment_length-1] == '"') {
|
|
comment_arg[comment_length-1] = '\0'; /* zap terminating quote */
|
|
break;
|
|
}
|
|
if (++argn >= argc)
|
|
ERREXIT("Missing ending quote mark");
|
|
strcat(comment_arg, " ");
|
|
strcat(comment_arg, argv[argn]);
|
|
}
|
|
}
|
|
comment_length = (unsigned int) strlen(comment_arg);
|
|
} else
|
|
usage();
|
|
}
|
|
|
|
/* Cannot use both -comment and -cfile. */
|
|
if (comment_arg != NULL && comment_file != NULL)
|
|
usage();
|
|
/* If there is neither -comment nor -cfile, we will read the comment text
|
|
* from stdin; in this case there MUST be an input JPEG file name.
|
|
*/
|
|
if (comment_arg == NULL && comment_file == NULL && argn >= argc)
|
|
usage();
|
|
|
|
/* Open the input file. */
|
|
if (argn < argc) {
|
|
if ((infile = fopen(argv[argn], READ_BINARY)) == NULL) {
|
|
fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
} else {
|
|
/* default input file is stdin */
|
|
#ifdef USE_SETMODE /* need to hack file mode? */
|
|
setmode(fileno(stdin), O_BINARY);
|
|
#endif
|
|
#ifdef USE_FDOPEN /* need to re-open in binary mode? */
|
|
if ((infile = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
|
|
fprintf(stderr, "%s: can't open stdin\n", progname);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
#else
|
|
infile = stdin;
|
|
#endif
|
|
}
|
|
|
|
/* Open the output file. */
|
|
#ifdef TWO_FILE_COMMANDLINE
|
|
/* Must have explicit output file name */
|
|
if (argn != argc-2) {
|
|
fprintf(stderr, "%s: must name one input and one output file\n",
|
|
progname);
|
|
usage();
|
|
}
|
|
if ((outfile = fopen(argv[argn+1], WRITE_BINARY)) == NULL) {
|
|
fprintf(stderr, "%s: can't open %s\n", progname, argv[argn+1]);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
#else
|
|
/* Unix style: expect zero or one file name */
|
|
if (argn < argc-1) {
|
|
fprintf(stderr, "%s: only one input file\n", progname);
|
|
usage();
|
|
}
|
|
/* default output file is stdout */
|
|
#ifdef USE_SETMODE /* need to hack file mode? */
|
|
setmode(fileno(stdout), O_BINARY);
|
|
#endif
|
|
#ifdef USE_FDOPEN /* need to re-open in binary mode? */
|
|
if ((outfile = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
|
|
fprintf(stderr, "%s: can't open stdout\n", progname);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
#else
|
|
outfile = stdout;
|
|
#endif
|
|
#endif /* TWO_FILE_COMMANDLINE */
|
|
|
|
/* Collect comment text from comment_file or stdin, if necessary */
|
|
if (comment_arg == NULL) {
|
|
FILE * src_file;
|
|
int c;
|
|
|
|
comment_arg = (char *) malloc((size_t) MAX_COM_LENGTH);
|
|
if (comment_arg == NULL)
|
|
ERREXIT("Insufficient memory");
|
|
comment_length = 0;
|
|
src_file = (comment_file != NULL ? comment_file : stdin);
|
|
while ((c = getc(src_file)) != EOF) {
|
|
if (comment_length >= (unsigned int) MAX_COM_LENGTH) {
|
|
fprintf(stderr, "Comment text may not exceed %u bytes\n",
|
|
(unsigned int) MAX_COM_LENGTH);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
comment_arg[comment_length++] = (char) c;
|
|
}
|
|
if (comment_file != NULL)
|
|
fclose(comment_file);
|
|
}
|
|
|
|
/* Copy JPEG headers until SOFn marker;
|
|
* we will insert the new comment marker just before SOFn.
|
|
* This (a) causes the new comment to appear after, rather than before,
|
|
* existing comments; and (b) ensures that comments come after any JFIF
|
|
* or JFXX markers, as required by the JFIF specification.
|
|
*/
|
|
marker = scan_JPEG_header(keep_COM);
|
|
/* Insert the new COM marker, but only if nonempty text has been supplied */
|
|
if (comment_length > 0) {
|
|
write_marker(M_COM);
|
|
write_2_bytes(comment_length + 2);
|
|
while (comment_length > 0) {
|
|
write_1_byte(*comment_arg++);
|
|
comment_length--;
|
|
}
|
|
}
|
|
/* Duplicate the remainder of the source file.
|
|
* Note that any COM markers occuring after SOF will not be touched.
|
|
*/
|
|
write_marker(marker);
|
|
copy_rest_of_file();
|
|
|
|
/* All done. */
|
|
exit(EXIT_SUCCESS);
|
|
return 0; /* suppress no-return-value warnings */
|
|
}
|