04bd0621bc48e2a67bf12fa3a7b34097ec16a99c
[libav.git] / libavformat / m4vdec.c
1 /*
2 * RAW MPEG-4 video demuxer
3 * Copyright (c) 2006 Thijs Vermeir <thijs.vermeir@barco.com>
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "avformat.h"
23 #include "rawdec.h"
24
25 #define VISUAL_OBJECT_START_CODE 0x000001b5
26 #define VOP_START_CODE 0x000001b6
27
28 static int mpeg4video_probe(AVProbeData *probe_packet)
29 {
30 uint32_t temp_buffer= -1;
31 int VO=0, VOL=0, VOP = 0, VISO = 0, res=0;
32 int i;
33
34 for(i=0; i<probe_packet->buf_size; i++){
35 temp_buffer = (temp_buffer<<8) + probe_packet->buf[i];
36 if ((temp_buffer & 0xffffff00) != 0x100)
37 continue;
38
39 if (temp_buffer == VOP_START_CODE) VOP++;
40 else if (temp_buffer == VISUAL_OBJECT_START_CODE) VISO++;
41 else if (temp_buffer < 0x120) VO++;
42 else if (temp_buffer < 0x130) VOL++;
43 else if ( !(0x1AF < temp_buffer && temp_buffer < 0x1B7)
44 && !(0x1B9 < temp_buffer && temp_buffer < 0x1C4)) res++;
45 }
46
47 if (VOP >= VISO && VOP >= VOL && VO >= VOL && VOL > 0 && res==0)
48 return AVPROBE_SCORE_EXTENSION;
49 return 0;
50 }
51
52 FF_DEF_RAWVIDEO_DEMUXER(m4v, "raw MPEG-4 video", mpeg4video_probe, "m4v", AV_CODEC_ID_MPEG4)