/* * sample3.c * Copyright (C) 2003      Regis Duchesne <hpreg@zoy.org> * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org> * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca> * * This file is part of mpeg2dec, a free MPEG-2 video stream decoder. * See http://libmpeg2.sourceforge.net/ for updates. * * mpeg2dec 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. * * mpeg2dec 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 * * This program reads a MPEG-2 stream, and saves each of its frames as * an image file using the PGM format (black and white). * * It demonstrates how to use the following features of libmpeg2: * - Output buffers use the YUV 4:2:0 planar format. * - Output buffers are allocated by the caller but managed by the library. */#include <stdio.h>#include <stdlib.h>#include <inttypes.h>#include "mpeg2.h"static void save_pgm (int width, int height,		      int chroma_width, int chroma_height,		      uint8_t * const * buf, int num){    char filename[100];    FILE * pgmfile;    int i;    static uint8_t black[16384] = { 0 };    sprintf (filename, "%d.pgm", num);    pgmfile = fopen (filename, "wb");    if (!pgmfile) {	fprintf (stderr, "Could not open file \"%s\".\n", filename);	exit (1);    }    fprintf (pgmfile, "P5\n%d %d\n255\n",	     2 * chroma_width, height + chroma_height);    for (i = 0; i < height; i++) {	fwrite (buf[0] + i * width, width, 1, pgmfile);	fwrite (black, 2 * chroma_width - width, 1, pgmfile);    }    for (i = 0; i < chroma_height; i++) {	fwrite (buf[1] + i * chroma_width, chroma_width, 1, pgmfile);	fwrite (buf[2] + i * chroma_width, chroma_width, 1, pgmfile);    }    fclose (pgmfile);}static void sample3 (FILE * mpgfile){#define BUFFER_SIZE 4096    uint8_t buffer[BUFFER_SIZE];    mpeg2dec_t * decoder;    const mpeg2_info_t * info;    const mpeg2_sequence_t * sequence;    mpeg2_state_t state;    size_t size;    int framenum = 0;    uint8_t * fbuf[3][3];    int i, j;    decoder = mpeg2_init ();    if (decoder == NULL) {	fprintf (stderr, "Could not allocate a decoder object.\n");	exit (1);    }    info = mpeg2_info (decoder);    size = (size_t)-1;    do {	state = mpeg2_parse (decoder);	sequence = info->sequence;	switch (state) {	case STATE_BUFFER:	    size = fread (buffer, 1, BUFFER_SIZE, mpgfile);	    mpeg2_buffer (decoder, buffer, buffer + size);	    break;	case STATE_SEQUENCE:	    for (i = 0; i < 3; i++) {		fbuf[i][0] = (uint8_t *) malloc (sequence->width *						 sequence->height);		fbuf[i][1] = (uint8_t *) malloc (sequence->chroma_width * 						 sequence->chroma_height);		fbuf[i][2] = (uint8_t *) malloc (sequence->chroma_width *  						 sequence->chroma_height);		if (!fbuf[i][0] || !fbuf[i][1] || !fbuf[i][2]) {		    fprintf (stderr, "Could not allocate an output buffer.\n");		    exit (1);		}		mpeg2_set_buf (decoder, fbuf[i], NULL);	    }	    break;	case STATE_SLICE:	case STATE_END:	case STATE_INVALID_END:	    if (info->display_fbuf)		save_pgm (sequence->width, sequence->height,			  sequence->chroma_width, sequence->chroma_height,			  info->display_fbuf->buf, framenum++);	    if (state != STATE_SLICE)		for (i = 0; i < 3; i++)		    for (j = 0; j < 3; j++)			free (fbuf[i][j]);	    break;	default:	    break;	}    } while (size);    mpeg2_close (decoder);}int main (int argc, char ** argv){    FILE * mpgfile;    if (argc > 1) {	mpgfile = fopen (argv[1], "rb");	if (!mpgfile) {	    fprintf (stderr, "Could not open file \"%s\".\n", argv[1]);	    exit (1);	}    } else	mpgfile = stdin;    sample3 (mpgfile);    return 0;}