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/*
* 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(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;
for(i=0; i<p->buf_size; i++){
code = (code<<8) + p->buf[i];
if ((code & 0xfffffc0000) == 0x800000) {
src_fmt= (code>>2)&3;
if( src_fmt != last_src_fmt
&& last_src_fmt>0 && last_src_fmt<6
&& src_fmt<6)
res_change++;
if((code&0x300)==0x200 && src_fmt){
valid_psc++;
last_gn=0;
}else
invalid_psc++;
last_src_fmt= src_fmt;
} else if((code & 0xffff800000) == 0x800000) {
int gn= (code>>(23-5)) & 0x1F;
if(gn<last_gn){
invalid_psc++;
}else
last_gn= gn;
}
}
//av_log(NULL, AV_LOG_ERROR, "h263_probe: psc:%d invalid:%d res_change:%d\n", valid_psc, invalid_psc, res_change);
//h263_probe: psc:3 invalid:0 res_change:0 (1588/recent_ffmpeg_parses_mpg_incorrectly.mpg)
if(valid_psc > 2*invalid_psc + 2*res_change + 3){
return 50;
}else if(valid_psc > 2*invalid_psc)
return 25;
return 0;
}
FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, AV_CODEC_ID_H263)
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