ppmtoy4m.c

Motion JPEG编解码器源代码

/*
 * ppmtoy4m.c:  Generate a YUV4MPEG2 stream from one or more PPM images
 *
 *              Converts R'G'B' to ITU-Rec.601 Y'CbCr colorspace and
 *               performs 4:2:0 chroma subsampling.
 *
 *
 *  Copyright (C) 2004 Matthew J. Marjanovic <[e-mail]>
 *
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

#include <config.h>

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>

#include <yuv4mpeg.h>
#include <mpegconsts.h>
#include "subsample.h"
#include "colorspace.h"

#ifndef O_BINARY
# define O_BINARY 0
#endif

#define DEFAULT_CHROMA_MODE Y4M_CHROMA_444


/* command-line parameters */
typedef struct _cl_info {
  y4m_ratio_t aspect;    
  y4m_ratio_t framerate; 
  int interlace;         
  int interleave;
  int offset;
  int framecount;
  int repeatlast;
  int ss_mode;
  int verbosity;
  int fdin;
  int bgr;
} cl_info_t;


/* PPM image information */
typedef struct _ppm_info {
  int width;
  int height;
} ppm_info_t;



static
void usage(const char *progname)
{
  fprintf(stdout, "\n");
  fprintf(stdout, "usage:  %s [options] [ppm-file]\n", progname);
  fprintf(stdout, "\n");
  fprintf(stdout, "Reads RAW PPM image(s), and produces YUV4MPEG2 stream on stdout.\n");
  fprintf(stdout, "Converts computer graphics R'G'B' colorspace to digital video Y'CbCr,\n");
  fprintf(stdout, " and performs chroma subsampling.\n");
  fprintf(stdout, "\n");
  fprintf(stdout, "If 'ppm-file' is not specified, reads from stdin.\n");
  fprintf(stdout, "\n");
  fprintf(stdout, " options:  (defaults specified in [])\n");
  fprintf(stdout, "\n");
  fprintf(stdout, "  -o n     frame offset (skip n input frames) [0]\n");
  fprintf(stdout, "  -n n     frame count (output n frames; 0 == all of them) [0]\n");
  fprintf(stdout, "  -F n:d   framerate [30000:1001 = NTSC]\n");
  fprintf(stdout, "  -A w:h   pixel aspect ratio [1:1]\n");
  fprintf(stdout, "  -I x     interlacing [p]\n");
  fprintf(stdout, "             p = none/progressive\n");
  fprintf(stdout, "             t = top-field-first\n");
  fprintf(stdout, "             b = bottom-field-first\n");
  fprintf(stdout, "  -L       treat PPM images as 2-field interleaved\n");
  fprintf(stdout, "  -r       repeat last input frame\n");
  {
    int m;
    const char *keyword;

    fprintf(stdout, "  -S mode  chroma subsampling mode [%s]\n",
	    y4m_chroma_keyword(DEFAULT_CHROMA_MODE));
    for (m = 0;
	 (keyword = y4m_chroma_keyword(m)) != NULL;
	 m++)
      if (chroma_sub_implemented(m))
	fprintf(stdout, "            '%s' -> %s\n",
		keyword, y4m_chroma_description(m));
  }
  /*  fprintf(stdout, "  -R type  subsampling filter type\n");*/
  fprintf(stdout, "  -v n     verbosity (0,1,2) [1]\n");
  fprintf(stdout, "  -B       PPM image is packed with BGR pixels [RGB]\n");
}



static
void parse_args(cl_info_t *cl, int argc, char **argv)
{
  int c;

  cl->offset = 0;
  cl->framecount = 0;
  cl->aspect = y4m_sar_SQUARE;
  cl->interlace = Y4M_ILACE_NONE;
  cl->framerate = y4m_fps_NTSC;
  cl->interleave = 0;
  cl->repeatlast = 0;
  cl->ss_mode = DEFAULT_CHROMA_MODE;
  cl->verbosity = 1;
  cl->bgr = 0;
  cl->fdin = 0; /* default to stdin */

  while ((c = getopt(argc, argv, "BA:F:I:Lo:n:rS:v:h")) != -1) {
    switch (c) {
    case 'A':
      if (y4m_parse_ratio(&(cl->aspect), optarg) != Y4M_OK) {
	mjpeg_error("Could not parse ratio:  '%s'", optarg);
	goto ERROR_EXIT;
      }
      break;
    case 'F':
      if (y4m_parse_ratio(&(cl->framerate), optarg) != Y4M_OK) {
	mjpeg_error("Could not parse ratio:  '%s'", optarg);
	goto ERROR_EXIT;
      }
      break;
    case 'I':
      switch (optarg[0]) {
      case 'p':  cl->interlace = Y4M_ILACE_NONE;  break;
      case 't':  cl->interlace = Y4M_ILACE_TOP_FIRST;  break;
      case 'b':  cl->interlace = Y4M_ILACE_BOTTOM_FIRST;  break;
      default:
	mjpeg_error("Unknown value for interlace: '%c'", optarg[0]);
	goto ERROR_EXIT;
	break;
      }
      break;
    case 'L':
      cl->interleave = 1;
      break;
    case 'B':
      cl->bgr = 1;
      break;
    case 'o':
      if ((cl->offset = atoi(optarg)) < 0)
	mjpeg_error_exit1("Offset must be >= 0:  '%s'", optarg);
      break;
    case 'n':
      if ((cl->framecount = atoi(optarg)) < 0)
	mjpeg_error_exit1("Frame count must be >= 0:  '%s'", optarg);
      break;
    case 'r':
      cl->repeatlast = 1;
      break;
    case 'S':
      cl->ss_mode = y4m_chroma_parse_keyword(optarg);
      if (cl->ss_mode == Y4M_UNKNOWN) {
	mjpeg_error("Unknown subsampling mode option:  %s", optarg);
	goto ERROR_EXIT;
      } else if (!chroma_sub_implemented(cl->ss_mode)) {
	mjpeg_error("Unsupported subsampling mode option:  %s", optarg);
	goto ERROR_EXIT;
      }
      break;
    case 'v':
      cl->verbosity = atoi(optarg);
      if ((cl->verbosity < 0) || (cl->verbosity > 2))
	mjpeg_error("Verbosity must be 0, 1, or 2:  '%s'", optarg);
      break;
    case 'h':
      usage(argv[0]);
      exit(0);
      break;
    case '?':
    default:
      goto ERROR_EXIT;
      break;
    }
  }
  /* optional remaining argument is a filename */
  if (optind == (argc - 1)) {
    if ((cl->fdin = open(argv[optind], O_RDONLY | O_BINARY)) == -1)
      mjpeg_error_exit1("Failed to open '%s':  %s",
			argv[optind], strerror(errno));
  } else if (optind != argc) 
    goto ERROR_EXIT;


  mjpeg_default_handler_verbosity(cl->verbosity);

  mjpeg_info("Command-line Parameters:");
  mjpeg_info("             framerate:  %d:%d",
	     cl->framerate.n, cl->framerate.d);
  mjpeg_info("    pixel aspect ratio:  %d:%d",
	     cl->aspect.n, cl->aspect.d);
  mjpeg_info("         pixel packing:  %s",
	     cl->bgr?"BGR":"RGB");
  mjpeg_info("             interlace:  %s%s",
	     mpeg_interlace_code_definition(cl->interlace),
	     (cl->interlace == Y4M_ILACE_NONE) ? "" :
	     (cl->interleave) ? " (interleaved PPM input)" :
	     " (field-sequential PPM input)");
  mjpeg_info("        starting frame:  %d", cl->offset);
  if (cl->framecount == 0)
    mjpeg_info("           # of frames:  all%s",
	       (cl->repeatlast) ? ", repeat last frame forever" :
	       ", until input exhausted");
  else
    mjpeg_info("           # of frames:  %d%s",
	       cl->framecount,
	       (cl->repeatlast) ? ", repeat last frame until done" :
	       ", or until input exhausted");
  mjpeg_info("    chroma subsampling:  %s",
	     y4m_chroma_description(cl->ss_mode));

  /* DONE! */
  return;

 ERROR_EXIT:
  mjpeg_error("For usage hints, use option '-h'.  Please take a hint.");
  exit(1);

}



/*
 * returns:  0 - success, got header
 *           1 - EOF, no new frame
 *          -1 - failure
 */


#define DO_READ_NUMBER(var)                                     \
  do {                                                          \
    if (!isdigit(s[0]))                                         \
      mjpeg_error_exit1("PPM read error:  bad char");         \
    (var) = ((var) * 10) + (s[0] - '0');                        \
  } while (((n = read(fd, s, 1)) == 1) && (!isspace(s[0])));    \
  if (n <= 0) return -1;                                        



#define DO_SKIP_WHITESPACE()                                     \
  incomment = 0;                                                 \
  while ( ((n = read(fd, s, 1)) == 1) &&                         \
	  ((isspace(s[0])) || (s[0] == '#') || (incomment)) ) {  \
    if (s[0] == '#') incomment = 1;                              \
    if (s[0] == '\n') incomment = 0;                             \
  }                                                              \
  if (n <= 0) return -1;                                         


static
int read_ppm_header(int fd, int *width, int *height)
{
  char s[6];
  int incomment;
  int n;
  int maxval = 0;
  
  *width = 0;
  *height = 0;

  /* look for "P6" */
  n = y4m_read(fd, s, 3);
  if (n > 0) 
    return 1;  /* EOF */

  if ((n < 0) || (strncmp(s, "P6", 2)))
    mjpeg_error_exit1("Bad Raw PPM magic!");

  incomment = 0;
  DO_SKIP_WHITESPACE();
  DO_READ_NUMBER(*width);
  DO_SKIP_WHITESPACE();
  DO_READ_NUMBER(*height);
  DO_SKIP_WHITESPACE();
  DO_READ_NUMBER(maxval);

  if (maxval != 255)
    mjpeg_error_exit1("Expecting maxval == 255, not %d!", maxval);

  return 0;
}



static
void alloc_buffers(uint8_t *buffers[], int width, int height)
{
  mjpeg_debug("Alloc'ing buffers");
  buffers[0] = malloc(width * height * 2 * sizeof(buffers[0][0]));
  buffers[1] = malloc(width * height * 2 * sizeof(buffers[1][0]));
  buffers[2] = malloc(width * height * 2 * sizeof(buffers[2][0]));
}






static
void read_ppm_into_two_buffers(int fd,