/* * sample6.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 PPM format (color). * * It demonstrates how to use the following features of libmpeg2: * - Output buffers use the RGB 24-bit chunky format. * - Output buffers are allocated and managed by the caller. */#include <stdio.h>#include <stdlib.h>#include <inttypes.h>#include "mpeg2.h"#include "mpeg2convert.h"static void save_ppm (int width, int height, uint8_t * buf, int num){    char filename[100];    FILE * ppmfile;    sprintf (filename, "%d.ppm", num);    ppmfile = fopen (filename, "wb");    if (!ppmfile) {	fprintf (stderr, "Could not open file \"%s\".\n", filename);	exit (1);    }    fprintf (ppmfile, "P6\n%d %d\n255\n", width, height);    fwrite (buf, 3 * width, height, ppmfile);    fclose (ppmfile);}static struct fbuf_s {    uint8_t * rgb[3];    int used;} fbuf[3];static struct fbuf_s * get_fbuf (void){    int i;    for (i = 0; i < 3; i++)	if (!fbuf[i].used) {	    fbuf[i].used = 1;	    return fbuf + i;	}    fprintf (stderr, "Could not find a free fbuf.\n");    exit (1);}static void sample6 (FILE * mpgfile){#define BUFFER_SIZE 4096    uint8_t buffer[BUFFER_SIZE];    mpeg2dec_t * decoder;    const mpeg2_info_t * info;    mpeg2_state_t state;    size_t size;    int framenum = 0;    int pixels;    int i;    struct fbuf_s * current_fbuf;    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);	switch (state) {	case STATE_BUFFER:	    size = fread (buffer, 1, BUFFER_SIZE, mpgfile);	    mpeg2_buffer (decoder, buffer, buffer + size);	    break;	case STATE_SEQUENCE:	    mpeg2_convert (decoder, mpeg2convert_rgb24, NULL);	    mpeg2_custom_fbuf (decoder, 1);	    pixels = info->sequence->width * info->sequence->height;	    for (i = 0; i < 3; i++) {		fbuf[i].rgb[0] = (uint8_t *) malloc (3 * pixels);		fbuf[i].rgb[1] = fbuf[i].rgb[2] = NULL;		if (!fbuf[i].rgb[0]) {		    fprintf (stderr, "Could not allocate an output buffer.\n");		    exit (1);		}		fbuf[i].used = 0;	    }	    for (i = 0; i < 2; i++) {		current_fbuf = get_fbuf ();		mpeg2_set_buf (decoder, current_fbuf->rgb, current_fbuf);	    }	    break;	case STATE_PICTURE:	    current_fbuf = get_fbuf ();	    mpeg2_set_buf (decoder, current_fbuf->rgb, current_fbuf);	    break;	case STATE_SLICE:	case STATE_END:	case STATE_INVALID_END:	    if (info->display_fbuf)		save_ppm (info->sequence->width, info->sequence->height,			  info->display_fbuf->buf[0], framenum++);	    if (info->discard_fbuf)                ((struct fbuf_s *)info->discard_fbuf->id)->used = 0;	    if (state != STATE_SLICE)		for (i = 0; i < 3; i++)		    free (fbuf[i].rgb[0]);	    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;    sample6 (mpgfile);    return 0;}