1/*
2 * RAW MPEG video demuxer
3 * Copyright (c) 2002-2003 Fabrice Bellard
4 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
5 *
6 * This file is part of Libav.
7 *
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "avformat.h"
24#include "rawdec.h"
25
26#define SEQ_START_CODE          0x000001b3
27#define GOP_START_CODE          0x000001b8
28#define PICTURE_START_CODE      0x00000100
29#define SLICE_START_CODE        0x00000101
30#define PACK_START_CODE         0x000001ba
31#define VIDEO_ID                0x000001e0
32#define AUDIO_ID                0x000001c0
33
34static int mpegvideo_probe(AVProbeData *p)
35{
36    uint32_t code= -1;
37    int pic=0, seq=0, slice=0, pspack=0, pes=0;
38    int i;
39
40    for(i=0; i<p->buf_size; i++){
41        code = (code<<8) + p->buf[i];
42        if ((code & 0xffffff00) == 0x100) {
43            switch(code){
44            case     SEQ_START_CODE:   seq++; break;
45            case PICTURE_START_CODE:   pic++; break;
46            case   SLICE_START_CODE: slice++; break;
47            case    PACK_START_CODE: pspack++; break;
48            }
49            if     ((code & 0x1f0) == VIDEO_ID)   pes++;
50            else if((code & 0x1e0) == AUDIO_ID)   pes++;
51        }
52    }
53    if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !pes)
54        return pic>1 ? AVPROBE_SCORE_MAX/2+1 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
55    return 0;
56}
57
58FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, CODEC_ID_MPEG1VIDEO)
59