view release on metacpan or  search on metacpan

src/Source/LibJPEG/cjpeg.c  view on Meta::CPAN

/*
 * cjpeg.c
 *
 * Copyright (C) 1991-1998, Thomas G. Lane.
 * Modified 2003-2013 by 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 command-line user interface for the JPEG compressor.
 * It should work on any system with Unix- or MS-DOS-style command lines.
 *
 * Two different command line styles are permitted, depending on the
 * compile-time switch TWO_FILE_COMMANDLINE:
 *	cjpeg [options]  inputfile outputfile
 *	cjpeg [options]  [inputfile]
 * In the second style, output is always to standard output, which you'd
 * normally redirect to a file or pipe to some other program.  Input is
 * either from a named file or from standard input (typically redirected).
 * The second style is convenient on Unix but is unhelpful on systems that
 * don't support pipes.  Also, you MUST use the first style if your system
 * doesn't do binary I/O to stdin/stdout.
 * To simplify script writing, the "-outfile" switch is provided.  The syntax
 *	cjpeg [options]  -outfile outputfile  inputfile
 * works regardless of which command line style is used.
 */

#include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
#include "jversion.h"		/* for version message */

#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


/* Create the add-on message string table. */

#define JMESSAGE(code,string)	string ,

static const char * const cdjpeg_message_table[] = {
#include "cderror.h"
  NULL
};


/*
 * This routine determines what format the input file is,
 * and selects the appropriate input-reading module.
 *
 * To determine which family of input formats the file belongs to,
 * we may look only at the first byte of the file, since C does not
 * guarantee that more than one character can be pushed back with ungetc.
 * Looking at additional bytes would require one of these approaches:
 *     1) assume we can fseek() the input file (fails for piped input);
 *     2) assume we can push back more than one character (works in
 *        some C implementations, but unportable);
 *     3) provide our own buffering (breaks input readers that want to use
 *        stdio directly, such as the RLE library);
 * or  4) don't put back the data, and modify the input_init methods to assume
 *        they start reading after the start of file (also breaks RLE library).
 * #1 is attractive for MS-DOS but is untenable on Unix.
 *
 * The most portable solution for file types that can't be identified by their
 * first byte is to make the user tell us what they are.  This is also the
 * only approach for "raw" file types that contain only arbitrary values.
 * We presently apply this method for Targa files.  Most of the time Targa
 * files start with 0x00, so we recognize that case.  Potentially, however,
 * a Targa file could start with any byte value (byte 0 is the length of the
 * seldom-used ID field), so we provide a switch to force Targa input mode.
 */

static boolean is_targa;	/* records user -targa switch */


LOCAL(cjpeg_source_ptr)
select_file_type (j_compress_ptr cinfo, FILE * infile)
{
  int c;

  if (is_targa) {
#ifdef TARGA_SUPPORTED
    return jinit_read_targa(cinfo);
#else
    ERREXIT(cinfo, JERR_TGA_NOTCOMP);
#endif
  }

  if ((c = getc(infile)) == EOF)
    ERREXIT(cinfo, JERR_INPUT_EMPTY);
  if (ungetc(c, infile) == EOF)
    ERREXIT(cinfo, JERR_UNGETC_FAILED);

  switch (c) {
#ifdef BMP_SUPPORTED
  case 'B':
    return jinit_read_bmp(cinfo);
#endif
#ifdef GIF_SUPPORTED
  case 'G':
    return jinit_read_gif(cinfo);
#endif
#ifdef PPM_SUPPORTED
  case 'P':
    return jinit_read_ppm(cinfo);
#endif
#ifdef RLE_SUPPORTED
  case 'R':
    return jinit_read_rle(cinfo);
#endif
#ifdef TARGA_SUPPORTED
  case 0x00:
    return jinit_read_targa(cinfo);
#endif
  default:
    ERREXIT(cinfo, JERR_UNKNOWN_FORMAT);
    break;
  }

  return NULL;			/* suppress compiler warnings */
}


/*
 * Argument-parsing code.
 * The switch parser is designed to be useful with DOS-style command line
 * syntax, ie, intermixed switches and file names, where only the switches
 * to the left of a given file name affect processing of that file.
 * The main program in this file doesn't actually use this capability...
 */


static const char * progname;	/* program name for error messages */
static char * outfilename;	/* for -outfile switch */


LOCAL(void)
usage (void)
/* complain about bad command line */
{
  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, "  -quality N[,...]   Compression quality (0..100; 5-95 is useful range)\n");
  fprintf(stderr, "  -grayscale     Create monochrome JPEG file\n");
  fprintf(stderr, "  -rgb           Create RGB JPEG file\n");
#ifdef ENTROPY_OPT_SUPPORTED
  fprintf(stderr, "  -optimize      Optimize Huffman table (smaller file, but slow compression)\n");
#endif
#ifdef C_PROGRESSIVE_SUPPORTED
  fprintf(stderr, "  -progressive   Create progressive JPEG file\n");
#endif
#ifdef DCT_SCALING_SUPPORTED
  fprintf(stderr, "  -scale M/N     Scale image by fraction M/N, eg, 1/2\n");
#endif
#ifdef TARGA_SUPPORTED
  fprintf(stderr, "  -targa         Input file is Targa format (usually not needed)\n");
#endif
  fprintf(stderr, "Switches for advanced users:\n");
#ifdef C_ARITH_CODING_SUPPORTED
  fprintf(stderr, "  -arithmetic    Use arithmetic coding\n");
#endif
#ifdef DCT_SCALING_SUPPORTED
  fprintf(stderr, "  -block N       DCT block size (1..16; default is 8)\n");
#endif
#if JPEG_LIB_VERSION_MAJOR >= 9
  fprintf(stderr, "  -rgb1          Create RGB JPEG file with reversible color transform\n");
  fprintf(stderr, "  -bgycc         Create big gamut YCC JPEG file\n");
#endif
#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

src/Source/LibJPEG/cjpeg.c  view on Meta::CPAN

  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 = "cjpeg";		/* in case C library doesn't provide it */

  /* Initialize the JPEG compression object with default error handling. */
  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_compress(&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;

  /* Now safe to enable signal catcher. */
#ifdef NEED_SIGNAL_CATCHER
  enable_signal_catcher((j_common_ptr) &cinfo);
#endif

  /* Initialize JPEG parameters.
   * Much of this may be overridden later.
   * In particular, we don't yet know the input file's color space,
   * but we need to provide some value for jpeg_set_defaults() to work.
   */

  cinfo.in_color_space = JCS_RGB; /* arbitrary guess */
  jpeg_set_defaults(&cinfo);

  /* 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.
   */

  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

  /* Figure out the input file format, and set up to read it. */
  src_mgr = select_file_type(&cinfo, input_file);
  src_mgr->input_file = input_file;

  /* Read the input file header to obtain file size & colorspace. */
  (*src_mgr->start_input) (&cinfo, src_mgr);

  /* Now that we know input colorspace, fix colorspace-dependent defaults */
  jpeg_default_colorspace(&cinfo);

  /* Adjust default compression parameters by re-parsing the options */
  file_index = parse_switches(&cinfo, argc, argv, 0, TRUE);

  /* Specify data destination for compression */
  jpeg_stdio_dest(&cinfo, output_file);

  /* Start compressor */
  jpeg_start_compress(&cinfo, TRUE);

  /* Process data */
  while (cinfo.next_scanline < cinfo.image_height) {
    num_scanlines = (*src_mgr->get_pixel_rows) (&cinfo, src_mgr);
    (void) jpeg_write_scanlines(&cinfo, src_mgr->buffer, num_scanlines);
  }

  /* Finish compression and release memory */
  (*src_mgr->finish_input) (&cinfo, src_mgr);
  jpeg_finish_compress(&cinfo);