djpeg.c File Reference

#include "cdjpeg.h"
#include "jversion.h"
#include <ctype.h>
#include "cderror.h"

Include dependency graph for djpeg.c:

Go to the source code of this file.

Macros
#define	JMESSAGE(code, string)   string ,
#define	DEFAULT_FMT   FMT_PPM

Enumerations
enum	IMAGE_FORMATS {   FMT_BMP , FMT_GIF , FMT_GIF0 , FMT_OS2 ,   FMT_PPM , FMT_RLE , FMT_TARGA , FMT_TIFF }

Functions
	usage (void)
	parse_switches (j_decompress_ptr cinfo, int argc, char **argv, int last_file_arg_seen, boolean for_real)
	jpeg_getc (j_decompress_ptr cinfo)
	print_text_marker (j_decompress_ptr cinfo)
int	main (int argc, char **argv)

Variables
static const char *const	cdjpeg_message_table []
static IMAGE_FORMATS	requested_fmt
static const char *	progname
static char *	outfilename

Macro Definition Documentation

DEFAULT_FMT

#define DEFAULT_FMT   FMT_PPM

Definition at line 72 of file djpeg.c.

JMESSAGE

#define JMESSAGE	(		code,
			string
	)		string ,

Definition at line 45 of file djpeg.c.

Enumeration Type Documentation

IMAGE_FORMATS

enum IMAGE_FORMATS

Enumerator
FMT_BMP
FMT_GIF
FMT_GIF0
FMT_OS2
FMT_PPM
FMT_RLE
FMT_TARGA
FMT_TIFF

Definition at line 60 of file djpeg.c.

             {
    FMT_BMP,        /* BMP format (Windows flavor) */
    FMT_GIF,        /* GIF format (LZW compressed) */
    FMT_GIF0,       /* GIF format (uncompressed) */
    FMT_OS2,        /* BMP format (OS/2 flavor) */
    FMT_PPM,        /* PPM/PGM (PBMPLUS formats) */
    FMT_RLE,        /* RLE format */
    FMT_TARGA,      /* Targa format */
    FMT_TIFF        /* TIFF format */
} IMAGE_FORMATS;

Function Documentation

jpeg_getc()

jpeg_getc

(

j_decompress_ptr

cinfo

)

Definition at line 367 of file djpeg.c.

{
  struct jpeg_source_mgr * datasrc = cinfo->src;
 
  if (datasrc->bytes_in_buffer == 0) {
    if (! (*datasrc->fill_input_buffer) (cinfo))
      ERREXIT(cinfo, JERR_CANT_SUSPEND);
  }
  datasrc->bytes_in_buffer--;
  return GETJOCTET(*datasrc->next_input_byte++);
}

Referenced by print_text_marker().

main()

int main	(	int argc	,
		char **	argv
	)

Definition at line 437 of file djpeg.c.

{
  struct jpeg_decompress_struct cinfo;
  struct jpeg_error_mgr jerr;
#ifdef PROGRESS_REPORT
  struct cdjpeg_progress_mgr progress;
#endif
  int file_index;
  djpeg_dest_ptr dest_mgr = NULL;
  FILE * input_file;
  FILE * output_file;
  JDIMENSION num_scanlines;
 
  /* On Mac, fetch a command line. */
#ifdef USE_CCOMMAND
  argc = ccommand(&argv);
#endif
 
  progname = argv[0];
  if (progname == NULL || progname[0] == 0)
    progname = "djpeg";     /* in case C library doesn't provide it */
 
  /* Initialize the JPEG decompression object with default error handling. */
  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_decompress(&cinfo);
  /* Add some application-specific error messages (from cderror.h) */
  jerr.addon_message_table = cdjpeg_message_table;
  jerr.first_addon_message = JMSG_FIRSTADDONCODE;
  jerr.last_addon_message = JMSG_LASTADDONCODE;
 
  /* Insert custom marker processor for COM and APP12.
   * APP12 is used by some digital camera makers for textual info,
   * so we provide the ability to display it as text.
   * If you like, additional APPn marker types can be selected for display,
   * but don't try to override APP0 or APP14 this way (see libjpeg.txt).
   */
  jpeg_set_marker_processor(&cinfo, JPEG_COM, print_text_marker);
  jpeg_set_marker_processor(&cinfo, JPEG_APP0+12, print_text_marker);
 
  /* Now safe to enable signal catcher. */
#ifdef NEED_SIGNAL_CATCHER
  enable_signal_catcher((j_common_ptr) &cinfo);
#endif
 
  /* Scan command line to find file names. */
  /* It is convenient to use just one switch-parsing routine, but the switch
   * values read here are ignored; we will rescan the switches after opening
   * the input file.
   * (Exception: tracing level set here controls verbosity for COM markers
   * found during jpeg_read_header...)
   */
 
  file_index = parse_switches(&cinfo, argc, argv, 0, FALSE);
 
#ifdef TWO_FILE_COMMANDLINE
  /* Must have either -outfile switch or explicit output file name */
  if (outfilename == NULL) {
    if (file_index != argc-2) {
      fprintf(stderr, "%s: must name one input and one output file\n",
          progname);
      usage();
    }
    outfilename = argv[file_index+1];
  } else {
    if (file_index != argc-1) {
      fprintf(stderr, "%s: must name one input and one output file\n",
          progname);
      usage();
    }
  }
#else
  /* Unix style: expect zero or one file name */
  if (file_index < argc-1) {
    fprintf(stderr, "%s: only one input file\n", progname);
    usage();
  }
#endif /* TWO_FILE_COMMANDLINE */
 
  /* Open the input file. */
  if (file_index < argc) {
    if ((input_file = fopen(argv[file_index], READ_BINARY)) == NULL) {
      fprintf(stderr, "%s: can't open %s\n", progname, argv[file_index]);
      exit(EXIT_FAILURE);
    }
  } else {
    /* default input file is stdin */
    input_file = read_stdin();
  }
 
  /* Open the output file. */
  if (outfilename != NULL) {
    if ((output_file = fopen(outfilename, WRITE_BINARY)) == NULL) {
      fprintf(stderr, "%s: can't open %s\n", progname, outfilename);
      exit(EXIT_FAILURE);
    }
  } else {
    /* default output file is stdout */
    output_file = write_stdout();
  }
 
#ifdef PROGRESS_REPORT
  start_progress_monitor((j_common_ptr) &cinfo, &progress);
#endif
 
  /* Specify data source for decompression */
  jpeg_stdio_src(&cinfo, input_file);
 
  /* Read file header, set default decompression parameters */
  (void) jpeg_read_header(&cinfo, TRUE);
 
  /* Adjust default decompression parameters by re-parsing the options */
  file_index = parse_switches(&cinfo, argc, argv, 0, TRUE);
 
  /* Initialize the output module now to let it override any crucial
   * option settings (for instance, GIF wants to force color quantization).
   */
  switch (requested_fmt) {
#ifdef BMP_SUPPORTED
  case FMT_BMP:
    dest_mgr = jinit_write_bmp(&cinfo, FALSE);
    break;
  case FMT_OS2:
    dest_mgr = jinit_write_bmp(&cinfo, TRUE);
    break;
#endif
#ifdef GIF_SUPPORTED
  case FMT_GIF:
    dest_mgr = jinit_write_gif(&cinfo, TRUE);
    break;
  case FMT_GIF0:
    dest_mgr = jinit_write_gif(&cinfo, FALSE);
    break;
#endif
#ifdef PPM_SUPPORTED
  case FMT_PPM:
    dest_mgr = jinit_write_ppm(&cinfo);
    break;
#endif
#ifdef RLE_SUPPORTED
  case FMT_RLE:
    dest_mgr = jinit_write_rle(&cinfo);
    break;
#endif
#ifdef TARGA_SUPPORTED
  case FMT_TARGA:
    dest_mgr = jinit_write_targa(&cinfo);
    break;
#endif
  default:
    ERREXIT(&cinfo, JERR_UNSUPPORTED_FORMAT);
  }
  dest_mgr->output_file = output_file;
 
  /* Start decompressor */
  (void) jpeg_start_decompress(&cinfo);
 
  /* Write output file header */
  (*dest_mgr->start_output) (&cinfo, dest_mgr);
 
  /* Process data */
  while (cinfo.output_scanline < cinfo.output_height) {
    num_scanlines = jpeg_read_scanlines(&cinfo, dest_mgr->buffer,
                    dest_mgr->buffer_height);
    (*dest_mgr->put_pixel_rows) (&cinfo, dest_mgr, num_scanlines);
  }
 
#ifdef PROGRESS_REPORT
  /* Hack: count final pass as done in case finish_output does an extra pass.
   * The library won't have updated completed_passes.
   */
  progress.pub.completed_passes = progress.pub.total_passes;
#endif
 
  /* Finish decompression and release memory.
   * I must do it in this order because output module has allocated memory
   * of lifespan JPOOL_IMAGE; it needs to finish before releasing memory.
   */
  (*dest_mgr->finish_output) (&cinfo, dest_mgr);
  (void) jpeg_finish_decompress(&cinfo);
  jpeg_destroy_decompress(&cinfo);
 
  /* Close files, if we opened them */
  if (input_file != stdin)
    fclose(input_file);
  if (output_file != stdout)
    fclose(output_file);
 
#ifdef PROGRESS_REPORT
  end_progress_monitor((j_common_ptr) &cinfo);
#endif
 
  /* All done. */
  exit(jerr.num_warnings ? EXIT_WARNING : EXIT_SUCCESS);
  return 0;         /* suppress no-return-value warnings */
}

parse_switches()

parse_switches	(	j_decompress_ptr	cinfo,
		int	argc,
		char **	argv,
		int	last_file_arg_seen,
		boolean	for_real
	)

Definition at line 167 of file djpeg.c.

{
  int argn;
  char * arg;
 
  /* Set up default JPEG parameters. */
  requested_fmt = DEFAULT_FMT;  /* set default output file format */
  outfilename = NULL;
  cinfo->err->trace_level = 0;
 
  /* Scan command line options, adjust parameters */
 
  for (argn = 1; argn < argc; argn++) {
    arg = argv[argn];
    if (*arg != '-') {
      /* Not a switch, must be a file name argument */
      if (argn <= last_file_arg_seen) {
    outfilename = NULL; /* -outfile applies to just one input file */
    continue;       /* ignore this name if previously processed */
      }
      break;            /* else done parsing switches */
    }
    arg++;          /* advance past switch marker character */
 
    if (keymatch(arg, "bmp", 1)) {
      /* BMP output format (Windows flavor). */
      requested_fmt = FMT_BMP;
 
    } else if (keymatch(arg, "colors", 1) || keymatch(arg, "colours", 1) ||
           keymatch(arg, "quantize", 1) || keymatch(arg, "quantise", 1)) {
      /* Do color quantization. */
      int val;
 
      if (++argn >= argc)   /* advance to next argument */
    usage();
      if (sscanf(argv[argn], "%d", &val) != 1)
    usage();
      cinfo->desired_number_of_colors = val;
      cinfo->quantize_colors = TRUE;
 
    } else if (keymatch(arg, "dct", 2)) {
      /* Select IDCT algorithm. */
      if (++argn >= argc)   /* advance to next argument */
    usage();
      if (keymatch(argv[argn], "int", 1)) {
    cinfo->dct_method = JDCT_ISLOW;
      } else if (keymatch(argv[argn], "fast", 2)) {
    cinfo->dct_method = JDCT_IFAST;
      } else if (keymatch(argv[argn], "float", 2)) {
    cinfo->dct_method = JDCT_FLOAT;
      } else
    usage();
 
    } else if (keymatch(arg, "dither", 2)) {
      /* Select dithering algorithm. */
      if (++argn >= argc)   /* advance to next argument */
    usage();
      if (keymatch(argv[argn], "fs", 2)) {
    cinfo->dither_mode = JDITHER_FS;
      } else if (keymatch(argv[argn], "none", 2)) {
    cinfo->dither_mode = JDITHER_NONE;
      } else if (keymatch(argv[argn], "ordered", 2)) {
    cinfo->dither_mode = JDITHER_ORDERED;
      } else
    usage();
 
    } else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
      /* Enable debug printouts. */
      /* On first -d, print version identification */
      static boolean printed_version = FALSE;
 
      if (! printed_version) {
    fprintf(stderr, "Independent JPEG Group's DJPEG, version %s\n%s\n",
        JVERSION, JCOPYRIGHT);
    printed_version = TRUE;
      }
      cinfo->err->trace_level++;
 
    } else if (keymatch(arg, "fast", 1)) {
      /* Select recommended processing options for quick-and-dirty output. */
      cinfo->two_pass_quantize = FALSE;
      cinfo->dither_mode = JDITHER_ORDERED;
      if (! cinfo->quantize_colors) /* don't override an earlier -colors */
    cinfo->desired_number_of_colors = 216;
      cinfo->dct_method = JDCT_FASTEST;
      cinfo->do_fancy_upsampling = FALSE;
 
    } else if (keymatch(arg, "gif", 1)) {
      /* GIF output format (LZW compressed). */
      requested_fmt = FMT_GIF;
 
    } else if (keymatch(arg, "gif0", 4)) {
      /* GIF output format (uncompressed). */
      requested_fmt = FMT_GIF0;
 
    } else if (keymatch(arg, "grayscale", 2) || keymatch(arg, "greyscale",2)) {
      /* Force monochrome output. */
      cinfo->out_color_space = JCS_GRAYSCALE;
 
    } else if (keymatch(arg, "rgb", 3)) {
      /* Force RGB output. */
      cinfo->out_color_space = JCS_RGB;
 
    } else if (keymatch(arg, "map", 3)) {
      /* Quantize to a color map taken from an input file. */
      if (++argn >= argc)   /* advance to next argument */
    usage();
      if (for_real) {       /* too expensive to do twice! */
#ifdef QUANT_2PASS_SUPPORTED    /* otherwise can't quantize to supplied map */
    FILE * mapfile;
 
    if ((mapfile = fopen(argv[argn], READ_BINARY)) == NULL) {
      fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
      exit(EXIT_FAILURE);
    }
    read_color_map(cinfo, mapfile);
    fclose(mapfile);
    cinfo->quantize_colors = TRUE;
#else
    ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
      }
 
    } else if (keymatch(arg, "maxmemory", 3)) {
      /* Maximum memory in Kb (or Mb with 'm'). */
      long lval;
      char ch = 'x';
 
      if (++argn >= argc)   /* advance to next argument */
    usage();
      if (sscanf(argv[argn], "%ld%c", &lval, &ch) < 1)
    usage();
      if (ch == 'm' || ch == 'M')
    lval *= 1000L;
      cinfo->mem->max_memory_to_use = lval * 1000L;
 
    } else if (keymatch(arg, "nosmooth", 3)) {
      /* Suppress fancy upsampling. */
      cinfo->do_fancy_upsampling = FALSE;
 
    } else if (keymatch(arg, "onepass", 3)) {
      /* Use fast one-pass quantization. */
      cinfo->two_pass_quantize = FALSE;
 
    } else if (keymatch(arg, "os2", 3)) {
      /* BMP output format (OS/2 flavor). */
      requested_fmt = FMT_OS2;
 
    } else if (keymatch(arg, "outfile", 4)) {
      /* Set output file name. */
      if (++argn >= argc)   /* advance to next argument */
    usage();
      outfilename = argv[argn]; /* save it away for later use */
 
    } else if (keymatch(arg, "pnm", 1) || keymatch(arg, "ppm", 1)) {
      /* PPM/PGM output format. */
      requested_fmt = FMT_PPM;
 
    } else if (keymatch(arg, "rle", 1)) {
      /* RLE output format. */
      requested_fmt = FMT_RLE;
 
    } else if (keymatch(arg, "scale", 1)) {
      /* Scale the output image by a fraction M/N. */
      if (++argn >= argc)   /* advance to next argument */
    usage();
      if (sscanf(argv[argn], "%u/%u",
         &cinfo->scale_num, &cinfo->scale_denom) < 1)
    usage();
 
    } else if (keymatch(arg, "targa", 1)) {
      /* Targa output format. */
      requested_fmt = FMT_TARGA;
 
    } else {
      usage();          /* bogus switch */
    }
  }
 
  return argn;          /* return index of next arg (file name) */
}

Referenced by main().

print_text_marker()

print_text_marker

(

j_decompress_ptr

cinfo

)

Definition at line 382 of file djpeg.c.

{
  boolean traceit = (cinfo->err->trace_level >= 1);
  INT32 length;
  unsigned int ch;
  unsigned int lastch = 0;
 
  length = jpeg_getc(cinfo) << 8;
  length += jpeg_getc(cinfo);
  length -= 2;          /* discount the length word itself */
 
  if (traceit) {
    if (cinfo->unread_marker == JPEG_COM)
      fprintf(stderr, "Comment, length %ld:\n", (long) length);
    else            /* assume it is an APPn otherwise */
      fprintf(stderr, "APP%d, length %ld:\n",
          cinfo->unread_marker - JPEG_APP0, (long) length);
  }
 
  while (--length >= 0) {
    ch = jpeg_getc(cinfo);
    if (traceit) {
      /* 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.
       */
      if (ch == '\r') {
    fprintf(stderr, "\n");
      } else if (ch == '\n') {
    if (lastch != '\r')
      fprintf(stderr, "\n");
      } else if (ch == '\\') {
    fprintf(stderr, "\\\\");
      } else if (isprint(ch)) {
    putc(ch, stderr);
      } else {
    fprintf(stderr, "\\%03o", ch);
      }
      lastch = ch;
    }
  }
 
  if (traceit)
    fprintf(stderr, "\n");
 
  return TRUE;
}

Referenced by main().

usage()

usage

(

void

)

Definition at line 92 of file djpeg.c.

{
  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, "  -colors N      Reduce image to no more than N colors\n");
  fprintf(stderr, "  -fast          Fast, low-quality processing\n");
  fprintf(stderr, "  -grayscale     Force grayscale output\n");
  fprintf(stderr, "  -rgb           Force RGB output\n");
#ifdef IDCT_SCALING_SUPPORTED
  fprintf(stderr, "  -scale M/N     Scale output image by fraction M/N, eg, 1/8\n");
#endif
#ifdef BMP_SUPPORTED
  fprintf(stderr, "  -bmp           Select BMP output format (Windows style)%s\n",
      (DEFAULT_FMT == FMT_BMP ? " (default)" : ""));
#endif
#ifdef GIF_SUPPORTED
  fprintf(stderr, "  -gif           Select GIF output format (LZW compressed)%s\n",
      (DEFAULT_FMT == FMT_GIF ? " (default)" : ""));
  fprintf(stderr, "  -gif0          Select GIF output format (uncompressed)%s\n",
      (DEFAULT_FMT == FMT_GIF0 ? " (default)" : ""));
#endif
#ifdef BMP_SUPPORTED
  fprintf(stderr, "  -os2           Select BMP output format (OS/2 style)%s\n",
      (DEFAULT_FMT == FMT_OS2 ? " (default)" : ""));
#endif
#ifdef PPM_SUPPORTED
  fprintf(stderr, "  -pnm           Select PBMPLUS (PPM/PGM) output format%s\n",
      (DEFAULT_FMT == FMT_PPM ? " (default)" : ""));
#endif
#ifdef RLE_SUPPORTED
  fprintf(stderr, "  -rle           Select Utah RLE output format%s\n",
      (DEFAULT_FMT == FMT_RLE ? " (default)" : ""));
#endif
#ifdef TARGA_SUPPORTED
  fprintf(stderr, "  -targa         Select Targa output format%s\n",
      (DEFAULT_FMT == FMT_TARGA ? " (default)" : ""));
#endif
  fprintf(stderr, "Switches for advanced users:\n");
#ifdef DCT_ISLOW_SUPPORTED
  fprintf(stderr, "  -dct int       Use integer DCT method%s\n",
      (JDCT_DEFAULT == JDCT_ISLOW ? " (default)" : ""));
#endif
#ifdef DCT_IFAST_SUPPORTED
  fprintf(stderr, "  -dct fast      Use fast integer DCT (less accurate)%s\n",
      (JDCT_DEFAULT == JDCT_IFAST ? " (default)" : ""));
#endif
#ifdef DCT_FLOAT_SUPPORTED
  fprintf(stderr, "  -dct float     Use floating-point DCT method%s\n",
      (JDCT_DEFAULT == JDCT_FLOAT ? " (default)" : ""));
#endif
  fprintf(stderr, "  -dither fs     Use F-S dithering (default)\n");
  fprintf(stderr, "  -dither none   Don't use dithering in quantization\n");
  fprintf(stderr, "  -dither ordered  Use ordered dither (medium speed, quality)\n");
#ifdef QUANT_2PASS_SUPPORTED
  fprintf(stderr, "  -map FILE      Map to colors used in named image file\n");
#endif
  fprintf(stderr, "  -nosmooth      Don't use high-quality upsampling\n");
#ifdef QUANT_1PASS_SUPPORTED
  fprintf(stderr, "  -onepass       Use 1-pass quantization (fast, low quality)\n");
#endif
  fprintf(stderr, "  -maxmemory N   Maximum memory to use (in kbytes)\n");
  fprintf(stderr, "  -outfile name  Specify name for output file\n");
  fprintf(stderr, "  -verbose  or  -debug   Emit debug output\n");
  exit(EXIT_FAILURE);
}

Referenced by main(), and parse_switches().

Variable Documentation

cdjpeg_message_table

const char* const cdjpeg_message_table[]

static

Initial value:

= {
 
  NULL
}

Definition at line 47 of file djpeg.c.

Referenced by main().

outfilename

char* outfilename

static

Definition at line 88 of file djpeg.c.

Referenced by main(), and parse_switches().

progname

const char* progname

static

Definition at line 87 of file djpeg.c.

Referenced by main(), parse_switches(), and usage().

requested_fmt

IMAGE_FORMATS requested_fmt

static

Definition at line 75 of file djpeg.c.

Referenced by main(), and parse_switches().