yading@11: /*
yading@11:  * RAW H.263 video demuxer
yading@11:  * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "rawdec.h"
yading@11: 
yading@11: static int h263_probe(AVProbeData *p)
yading@11: {
yading@11:     uint64_t code= -1;
yading@11:     int i;
yading@11:     int valid_psc=0;
yading@11:     int invalid_psc=0;
yading@11:     int res_change=0;
yading@11:     int src_fmt, last_src_fmt=-1;
yading@11:     int last_gn=0;
yading@11: 
yading@11:     for(i=0; i<p->buf_size; i++){
yading@11:         code = (code<<8) + p->buf[i];
yading@11:         if ((code & 0xfffffc0000) == 0x800000) {
yading@11:             src_fmt= (code>>2)&3;
yading@11:             if(   src_fmt != last_src_fmt
yading@11:                && last_src_fmt>0 && last_src_fmt<6
yading@11:                && src_fmt<6)
yading@11:                 res_change++;
yading@11: 
yading@11:             if((code&0x300)==0x200 && src_fmt){
yading@11:                 valid_psc++;
yading@11:                 last_gn=0;
yading@11:             }else
yading@11:                 invalid_psc++;
yading@11:             last_src_fmt= src_fmt;
yading@11:         } else if((code & 0xffff800000) == 0x800000) {
yading@11:             int gn= (code>>(23-5)) & 0x1F;
yading@11:             if(gn<last_gn){
yading@11:                 invalid_psc++;
yading@11:             }else
yading@11:                 last_gn= gn;
yading@11:         }
yading@11:     }
yading@11:     if(valid_psc > 2*invalid_psc + 2*res_change + 3){
yading@11:         return 50;
yading@11:     }else if(valid_psc > 2*invalid_psc)
yading@11:         return 25;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, AV_CODEC_ID_H263)