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2ba45a60 DM |
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 FFmpeg. | |
7 | * | |
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. | |
12 | * | |
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. | |
17 | * | |
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 | |
21 | */ | |
22 | ||
23 | #include "avformat.h" | |
24 | #include "rawdec.h" | |
25 | ||
26 | #include "libavutil/intreadwrite.h" | |
27 | ||
28 | #define SEQ_START_CODE 0x000001b3 | |
29 | #define GOP_START_CODE 0x000001b8 | |
30 | #define PICTURE_START_CODE 0x00000100 | |
31 | #define SLICE_START_CODE 0x00000101 | |
32 | #define PACK_START_CODE 0x000001ba | |
33 | #define VIDEO_ID 0x000001e0 | |
34 | #define AUDIO_ID 0x000001c0 | |
35 | ||
36 | static int mpegvideo_probe(AVProbeData *p) | |
37 | { | |
38 | uint32_t code= -1; | |
39 | int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0; | |
40 | int i, j; | |
41 | uint32_t last = 0; | |
42 | ||
43 | for(i=0; i<p->buf_size; i++){ | |
44 | code = (code<<8) + p->buf[i]; | |
45 | if ((code & 0xffffff00) == 0x100) { | |
46 | switch(code){ | |
47 | case SEQ_START_CODE: | |
48 | if (!(p->buf[i+1+3+1+2] & 0x20)) | |
49 | break; | |
50 | j = i; | |
51 | if (p->buf[j+8] & 2) | |
52 | j+= 64; | |
53 | if (j >= p->buf_size) | |
54 | break; | |
55 | if (p->buf[j+8] & 1) | |
56 | j+= 64; | |
57 | if (j >= p->buf_size) | |
58 | break; | |
59 | if (AV_RB24(p->buf + j + 9) & 0xFFFFFE) | |
60 | break; | |
61 | seq++; | |
62 | break; | |
63 | case PICTURE_START_CODE: pic++; break; | |
64 | case PACK_START_CODE: pspack++; break; | |
65 | case 0x1b6: | |
66 | res++; break; | |
67 | } | |
68 | if (code >= SLICE_START_CODE && code <= 0x1af) { | |
69 | if (last >= SLICE_START_CODE && last <= 0x1af) { | |
70 | if (code >= last) slice++; | |
71 | else sicle++; | |
72 | }else{ | |
73 | if (code == SLICE_START_CODE) slice++; | |
74 | else sicle++; | |
75 | } | |
76 | } | |
77 | if ((code & 0x1f0) == VIDEO_ID) vpes++; | |
78 | else if((code & 0x1e0) == AUDIO_ID) apes++; | |
79 | last = code; | |
80 | } | |
81 | } | |
82 | if(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !apes && !res && slice > sicle) { | |
83 | if(vpes) return AVPROBE_SCORE_EXTENSION / 4; | |
84 | else return pic>1 ? AVPROBE_SCORE_EXTENSION + 1 : AVPROBE_SCORE_EXTENSION / 2; // +1 for .mpg | |
85 | } | |
86 | return 0; | |
87 | } | |
88 | ||
89 | FF_DEF_RAWVIDEO_DEMUXER(mpegvideo, "raw MPEG video", mpegvideo_probe, NULL, AV_CODEC_ID_MPEG1VIDEO) |