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 25static 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//av_log(NULL, AV_LOG_ERROR, "h263_probe: psc:%d invalid:%d res_change:%d\n", valid_psc, invalid_psc, res_change); 59//h263_probe: psc:3 invalid:0 res_change:0 (1588/recent_ffmpeg_parses_mpg_incorrectly.mpg) 60 if(valid_psc > 2*invalid_psc + 2*res_change + 3){ 61 return 50; 62 }else if(valid_psc > 2*invalid_psc) 63 return 25; 64 return 0; 65} 66 67FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, CODEC_ID_H263) 68