2 * RAW MPEG video demuxer
3 * Copyright (c) 2002-2003 Fabrice Bellard
4 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
6 * This file is part of FFmpeg.
8 * FFmpeg 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.
13 * FFmpeg 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.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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
34 static int mpegvideo_probe(AVProbeData *p)
37 int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0;
41 for(i=0; i<p->buf_size; i++){
42 code = (code<<8) + p->buf[i];
43 if ((code & 0xffffff00) == 0x100) {
45 case SEQ_START_CODE: seq++; break;
46 case PICTURE_START_CODE: pic++; break;
47 case PACK_START_CODE: pspack++; break;
51 if (code >= SLICE_START_CODE && code <= 0x1af) {
52 if (last >= SLICE_START_CODE && last <= 0x1af) {
53 if (code >= last) slice++;
56 if (code == SLICE_START_CODE) slice++;
60 if ((code & 0x1f0) == VIDEO_ID) vpes++;
61 else if((code & 0x1e0) == AUDIO_ID) apes++;
65 if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !apes && !res && slice > sicle) {
66 if(vpes) return AVPROBE_SCORE_EXTENSION / 4;
67 else return pic>1 ? AVPROBE_SCORE_EXTENSION + 1 : AVPROBE_SCORE_EXTENSION / 2; // +1 for .mpg
72 FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, AV_CODEC_ID_MPEG1VIDEO)