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67 lines
2.2 KiB
67 lines
2.2 KiB
/* |
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* RAW H.263 video demuxer |
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* Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "avformat.h" |
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#include "rawdec.h" |
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static int h263_probe(AVProbeData *p) |
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{ |
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uint64_t code= -1; |
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int i; |
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int valid_psc=0; |
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int invalid_psc=0; |
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int res_change=0; |
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int src_fmt, last_src_fmt=-1; |
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int last_gn=0; |
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for(i=0; i<p->buf_size; i++){ |
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code = (code<<8) + p->buf[i]; |
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if ((code & 0xfffffc0000) == 0x800000) { |
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src_fmt= (code>>2)&3; |
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if( src_fmt != last_src_fmt |
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&& last_src_fmt>0 && last_src_fmt<6 |
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&& src_fmt<6) |
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res_change++; |
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if((code&0x300)==0x200 && src_fmt){ |
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valid_psc++; |
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last_gn=0; |
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}else |
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invalid_psc++; |
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last_src_fmt= src_fmt; |
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} else if((code & 0xffff800000) == 0x800000) { |
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int gn= (code>>(23-5)) & 0x1F; |
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if(gn<last_gn){ |
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invalid_psc++; |
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}else |
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last_gn= gn; |
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} |
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} |
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//av_log(NULL, AV_LOG_ERROR, "h263_probe: psc:%d invalid:%d res_change:%d\n", valid_psc, invalid_psc, res_change); |
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//h263_probe: psc:3 invalid:0 res_change:0 (1588/recent_ffmpeg_parses_mpg_incorrectly.mpg) |
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if(valid_psc > 2*invalid_psc + 2*res_change + 3){ |
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return 50; |
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}else if(valid_psc > 2*invalid_psc) |
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return 25; |
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return 0; |
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} |
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FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, CODEC_ID_H263)
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