blob: 145fb859021114a9ee534a7b84e28293378dcd59
1 | /* |
2 | * RAW H.263 video demuxer |
3 | * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
7 | * FFmpeg 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 | * FFmpeg 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 FFmpeg; 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 | static int h263_probe(AVProbeData *p) |
26 | { |
27 | uint64_t code= -1; |
28 | int i; |
29 | int valid_psc=0; |
30 | int invalid_psc=0; |
31 | int res_change=0; |
32 | int src_fmt, last_src_fmt=-1; |
33 | int last_gn=0; |
34 | int tr, last_tr = -1; |
35 | |
36 | for(i=0; i<p->buf_size; i++){ |
37 | code = (code<<8) + p->buf[i]; |
38 | if ((code & 0xfffffc000000) == 0x80000000) { |
39 | tr = (code >> 18) & 0xFF; |
40 | src_fmt= (code>>10)&7; |
41 | if( src_fmt != last_src_fmt |
42 | && last_src_fmt>0 && last_src_fmt<6 |
43 | && src_fmt<6) |
44 | res_change++; |
45 | |
46 | if (tr == last_tr) { |
47 | invalid_psc++; |
48 | continue; |
49 | } |
50 | |
51 | if (src_fmt != 7 && !(code&(1<<9)) && (code&(1<<5))) { |
52 | invalid_psc++; |
53 | continue; |
54 | } |
55 | |
56 | if((code&0x30000)==0x20000 && src_fmt){ |
57 | valid_psc++; |
58 | last_gn=0; |
59 | }else |
60 | invalid_psc++; |
61 | last_src_fmt= src_fmt; |
62 | last_tr = tr; |
63 | } else if((code & 0xffff80000000) == 0x80000000) { |
64 | int gn= (code>>(31-5)) & 0x1F; |
65 | if(gn<last_gn){ |
66 | invalid_psc++; |
67 | }else |
68 | last_gn= gn; |
69 | } |
70 | } |
71 | if(valid_psc > 2*invalid_psc + 2*res_change + 3){ |
72 | return AVPROBE_SCORE_EXTENSION; |
73 | }else if(valid_psc > 2*invalid_psc) |
74 | return AVPROBE_SCORE_EXTENSION / 2; |
75 | return 0; |
76 | } |
77 | |
78 | FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, AV_CODEC_ID_H263) |
79 |