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Diffstat (limited to 'jpeg/rdjpgcom.c')
| -rwxr-xr-x | jpeg/rdjpgcom.c | 515 |
1 files changed, 0 insertions, 515 deletions
diff --git a/jpeg/rdjpgcom.c b/jpeg/rdjpgcom.c deleted file mode 100755 index 3719154..0000000 --- a/jpeg/rdjpgcom.c +++ /dev/null @@ -1,515 +0,0 @@ -/* - * rdjpgcom.c - * - * Copyright (C) 1994-1997, Thomas G. Lane. - * Modified 2009 by Bill Allombert, Guido Vollbeding. - * 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 displays - * the text in COM (comment) markers 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> */ - -#ifdef HAVE_LOCALE_H -#include <locale.h> /* Bill Allombert: use locale for isprint */ -#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" -#else -#ifdef VMS /* VMS is very nonstandard */ -#define READ_BINARY "rb", "ctx=stm" -#else /* standard ANSI-compliant case */ -#define READ_BINARY "rb" -#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 - - -/* - * These macros are used to read the input 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) - - -/* 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); -} - - -/* - * 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_APP0 0xE0 /* Application-specific marker, type N */ -#define M_APP12 0xEC /* (we don't bother to list all 16 APPn's) */ -#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. - * 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 -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--; - } -} - - -/* - * Process a COM marker. - * We want to print out the marker contents as legible text; - * we must guard against non-text junk and varying newline representations. - */ - -static void -process_COM (int raw) -{ - unsigned int length; - int ch; - int lastch = 0; - - /* Bill Allombert: set locale properly for isprint */ -#ifdef HAVE_LOCALE_H - setlocale(LC_CTYPE, ""); -#endif - - /* 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; - - while (length > 0) { - ch = read_1_byte(); - if (raw) { - putc(ch, stdout); - /* Emit the character in a readable form. - * Nonprintables are converted to \nnn form, - * while \ is converted to \\. - * Newlines in CR, CR/LF, or LF form will be printed as one newline. - */ - } else if (ch == '\r') { - printf("\n"); - } else if (ch == '\n') { - if (lastch != '\r') - printf("\n"); - } else if (ch == '\\') { - printf("\\\\"); - } else if (isprint(ch)) { - putc(ch, stdout); - } else { - printf("\\%03o", ch); - } - lastch = ch; - length--; - } - printf("\n"); - - /* Bill Allombert: revert to C locale */ -#ifdef HAVE_LOCALE_H - setlocale(LC_CTYPE, "C"); -#endif -} - - -/* - * Process a SOFn marker. - * This code is only needed if you want to know the image dimensions... - */ - -static void -process_SOFn (int marker) -{ - unsigned int length; - unsigned int image_height, image_width; - int data_precision, num_components; - const char * process; - int ci; - - length = read_2_bytes(); /* usual parameter length count */ - - data_precision = read_1_byte(); - image_height = read_2_bytes(); - image_width = read_2_bytes(); - num_components = read_1_byte(); - - switch (marker) { - case M_SOF0: process = "Baseline"; break; - case M_SOF1: process = "Extended sequential"; break; - case M_SOF2: process = "Progressive"; break; - case M_SOF3: process = "Lossless"; break; - case M_SOF5: process = "Differential sequential"; break; - case M_SOF6: process = "Differential progressive"; break; - case M_SOF7: process = "Differential lossless"; break; - case M_SOF9: process = "Extended sequential, arithmetic coding"; break; - case M_SOF10: process = "Progressive, arithmetic coding"; break; - case M_SOF11: process = "Lossless, arithmetic coding"; break; - case M_SOF13: process = "Differential sequential, arithmetic coding"; break; - case M_SOF14: process = "Differential progressive, arithmetic coding"; break; - case M_SOF15: process = "Differential lossless, arithmetic coding"; break; - default: process = "Unknown"; break; - } - - printf("JPEG image is %uw * %uh, %d color components, %d bits per sample\n", - image_width, image_height, num_components, data_precision); - printf("JPEG process: %s\n", process); - - if (length != (unsigned int) (8 + num_components * 3)) - ERREXIT("Bogus SOF marker length"); - - for (ci = 0; ci < num_components; ci++) { - (void) read_1_byte(); /* Component ID code */ - (void) read_1_byte(); /* H, V sampling factors */ - (void) read_1_byte(); /* Quantization table number */ - } -} - - -/* - * Parse the marker stream until SOS or EOI is seen; - * display any COM markers. - * While the companion program wrjpgcom will always insert COM markers before - * SOFn, other implementations might not, so we scan to SOS before stopping. - * If we were only interested in the image dimensions, we would stop at SOFn. - * (Conversely, if we only cared about COM markers, there would be no need - * for special code to handle SOFn; we could treat it like other markers.) - */ - -static int -scan_JPEG_header (int verbose, int raw) -{ - int marker; - - /* Expect SOI at start of file */ - if (first_marker() != M_SOI) - ERREXIT("Expected SOI marker first"); - - /* Scan miscellaneous markers until we reach SOS. */ - 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 */ - if (verbose) - process_SOFn(marker); - else - skip_variable(); - break; - - case M_SOS: /* stop before hitting compressed data */ - return marker; - - case M_EOI: /* in case it's a tables-only JPEG stream */ - return marker; - - case M_COM: - process_COM(raw); - break; - - case M_APP12: - /* Some digital camera makers put useful textual information into - * APP12 markers, so we print those out too when in -verbose mode. - */ - if (verbose) { - printf("APP12 contains:\n"); - process_COM(raw); - } else - skip_variable(); - break; - - default: /* Anything else just gets skipped */ - skip_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, "rdjpgcom displays any textual comments in a JPEG file.\n"); - - fprintf(stderr, "Usage: %s [switches] [inputfile]\n", progname); - - fprintf(stderr, "Switches (names may be abbreviated):\n"); - fprintf(stderr, " -raw Display non-printable characters in comments (unsafe)\n"); - fprintf(stderr, " -verbose Also display dimensions of JPEG image\n"); - - 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 verbose = 0, raw = 0; - - /* On Mac, fetch a command line. */ -#ifdef USE_CCOMMAND - argc = ccommand(&argv); -#endif - - progname = argv[0]; - if (progname == NULL || progname[0] == 0) - progname = "rdjpgcom"; /* 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, "verbose", 1)) { - verbose++; - } else if (keymatch(arg, "raw", 1)) { - raw = 1; - } else - usage(); - } - - /* Open the input file. */ - /* Unix style: expect zero or one file name */ - if (argn < argc-1) { - fprintf(stderr, "%s: only one input file\n", progname); - usage(); - } - 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 - } - - /* Scan the JPEG headers. */ - (void) scan_JPEG_header(verbose, raw); - - /* All done. */ - exit(EXIT_SUCCESS); - return 0; /* suppress no-return-value warnings */ -} |