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/*
 * 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 */
}

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[/] [openrisc/] [trunk/] [rtos/] [ecos-2.0/] [packages/] [services/] [gfx/] [mw/] [v2_0/] [src/] [jpeg-6b/] [wrjpgcom.c] - Blame information for rev 654

Line No.	Rev	Author	Line
1	27	unneback	`/*`
2			`* wrjpgcom.c`
3			`*`
4			`* Copyright (C) 1994-1997, Thomas G. Lane.`
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__`
29			`#include <SIOUX.h> /* Metrowerks needs this */`
30			`#include <console.h> /* ... and this */`
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`
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 */`
45			`#define READ_BINARY "rb"`
46			`#define WRITE_BINARY "wb"`
47			`#endif`
48			`#endif`
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`
66			`#define MAX_COM_LENGTH 65000L /* must be <= 65533 in any case */`
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 */`
159			`#define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */`
160			`#define M_SOF3 0xC3`
161			`#define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */`
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) {`
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			`*/`
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 (;;) {`
458			`comment_length = (unsigned int) strlen(comment_arg);`
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			`}`
469			`comment_length = (unsigned int) strlen(comment_arg);`
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			`}`