| /* |
| * RAW H.263 video demuxer |
| * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "avformat.h" |
| #include "rawdec.h" |
| |
| static int h263_probe(const AVProbeData *p) |
| { |
| uint64_t code= -1; |
| int i; |
| int valid_psc=0; |
| int invalid_psc=0; |
| int res_change=0; |
| int src_fmt, last_src_fmt=-1; |
| int last_gn=0; |
| int tr, last_tr = -1; |
| |
| for(i=0; i<p->buf_size; i++){ |
| code = (code<<8) + p->buf[i]; |
| if ((code & 0xfffffc000000) == 0x80000000) { |
| tr = (code >> 18) & 0xFF; |
| src_fmt= (code>>10)&7; |
| if( src_fmt != last_src_fmt |
| && last_src_fmt>0 && last_src_fmt<6 |
| && src_fmt<6) |
| res_change++; |
| |
| if (tr == last_tr) { |
| invalid_psc++; |
| continue; |
| } |
| |
| if (src_fmt != 7 && !(code&(1<<9)) && (code&(1<<5))) { |
| invalid_psc++; |
| continue; |
| } |
| |
| if((code&0x30000)==0x20000 && src_fmt){ |
| valid_psc++; |
| last_gn=0; |
| }else |
| invalid_psc++; |
| last_src_fmt= src_fmt; |
| last_tr = tr; |
| } else if((code & 0xffff80000000) == 0x80000000) { |
| int gn= (code>>(31-5)) & 0x1F; |
| if(gn<last_gn){ |
| invalid_psc++; |
| }else |
| last_gn= gn; |
| } |
| } |
| if(valid_psc > 2*invalid_psc + 2*res_change + 3){ |
| return AVPROBE_SCORE_EXTENSION; |
| }else if(valid_psc > 2*invalid_psc) |
| return AVPROBE_SCORE_EXTENSION / 2; |
| return 0; |
| } |
| |
| FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, AV_CODEC_ID_H263) |
