| 1 | /* |
| 2 | * RAW H.263 video demuxer |
| 3 | * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> |
| 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 | 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 | |
| 35 | for(i=0; i<p->buf_size; i++){ |
| 36 | code = (code<<8) + p->buf[i]; |
| 37 | if ((code & 0xfffffc0000) == 0x800000) { |
| 38 | src_fmt= (code>>2)&3; |
| 39 | if( src_fmt != last_src_fmt |
| 40 | && last_src_fmt>0 && last_src_fmt<6 |
| 41 | && src_fmt<6) |
| 42 | res_change++; |
| 43 | |
| 44 | if((code&0x300)==0x200 && src_fmt){ |
| 45 | valid_psc++; |
| 46 | last_gn=0; |
| 47 | }else |
| 48 | invalid_psc++; |
| 49 | last_src_fmt= src_fmt; |
| 50 | } else if((code & 0xffff800000) == 0x800000) { |
| 51 | int gn= (code>>(23-5)) & 0x1F; |
| 52 | if(gn<last_gn){ |
| 53 | invalid_psc++; |
| 54 | }else |
| 55 | last_gn= gn; |
| 56 | } |
| 57 | } |
| 58 | if(valid_psc > 2*invalid_psc + 2*res_change + 3){ |
| 59 | return AVPROBE_SCORE_EXTENSION; |
| 60 | }else if(valid_psc > 2*invalid_psc) |
| 61 | return AVPROBE_SCORE_EXTENSION / 2; |
| 62 | return 0; |
| 63 | } |
| 64 | |
| 65 | FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, AV_CODEC_ID_H263) |