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/*
* sample5.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>
* Copyright (C) 2006 Sam Hocevar <sam@zoy.org>
*
* 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 must be 16-byte aligned.
* - Output buffers are allocated and managed by the caller.
*/
#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 struct fbuf_s {
uint8_t * mbuf[3];
uint8_t * yuv[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 sample5 (FILE * mpgfile)
{
#define BUFFER_SIZE 4096
#define ALIGN_16(p) ((void *)(((uintptr_t)(p) + 15) & ~((uintptr_t)15)))
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;
int i, j;
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);
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:
mpeg2_custom_fbuf (decoder, 1);
for (i = 0; i < 3; i++) {
fbuf[i].mbuf[0] = (uint8_t *) malloc (sequence->width *
sequence->height + 15);
fbuf[i].mbuf[1] = (uint8_t *) malloc (sequence->chroma_width *
sequence->chroma_height + 15);
fbuf[i].mbuf[2] = (uint8_t *) malloc (sequence->chroma_width *
sequence->chroma_height + 15);
if (!fbuf[i].mbuf[0] || !fbuf[i].mbuf[1] || !fbuf[i].mbuf[2]) {
fprintf (stderr, "Could not allocate an output buffer.\n");
exit (1);
}
for (j = 0; j < 3; j++)
fbuf[i].yuv[j] = ALIGN_16 (fbuf[i].mbuf[j]);
fbuf[i].used = 0;
}
for (i = 0; i < 2; i++) {
current_fbuf = get_fbuf ();
mpeg2_set_buf (decoder, current_fbuf->yuv, current_fbuf);
}
break;
case STATE_PICTURE:
current_fbuf = get_fbuf ();
mpeg2_set_buf (decoder, current_fbuf->yuv, current_fbuf);
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 (info->discard_fbuf)
((struct fbuf_s *)info->discard_fbuf->id)->used = 0;
if (state != STATE_SLICE)
for (i = 0; i < 3; i++)
for (j = 0; j < 3; j++)
free (fbuf[i].mbuf[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;
sample5 (mpgfile);
return 0;
}
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