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Diffstat (limited to 'libjpegtwrp/wrjpgcom.c')
-rw-r--r-- | libjpegtwrp/wrjpgcom.c | 583 |
1 files changed, 583 insertions, 0 deletions
diff --git a/libjpegtwrp/wrjpgcom.c b/libjpegtwrp/wrjpgcom.c new file mode 100644 index 000000000..8c04b0551 --- /dev/null +++ b/libjpegtwrp/wrjpgcom.c @@ -0,0 +1,583 @@ +/* + * 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 */ +} |