1cabdff1aSopenharmony_ci/* 2cabdff1aSopenharmony_ci * RAW H.261 video demuxer 3cabdff1aSopenharmony_ci * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> 4cabdff1aSopenharmony_ci * 5cabdff1aSopenharmony_ci * This file is part of FFmpeg. 6cabdff1aSopenharmony_ci * 7cabdff1aSopenharmony_ci * FFmpeg is free software; you can redistribute it and/or 8cabdff1aSopenharmony_ci * modify it under the terms of the GNU Lesser General Public 9cabdff1aSopenharmony_ci * License as published by the Free Software Foundation; either 10cabdff1aSopenharmony_ci * version 2.1 of the License, or (at your option) any later version. 11cabdff1aSopenharmony_ci * 12cabdff1aSopenharmony_ci * FFmpeg is distributed in the hope that it will be useful, 13cabdff1aSopenharmony_ci * but WITHOUT ANY WARRANTY; without even the implied warranty of 14cabdff1aSopenharmony_ci * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15cabdff1aSopenharmony_ci * Lesser General Public License for more details. 16cabdff1aSopenharmony_ci * 17cabdff1aSopenharmony_ci * You should have received a copy of the GNU Lesser General Public 18cabdff1aSopenharmony_ci * License along with FFmpeg; if not, write to the Free Software 19cabdff1aSopenharmony_ci * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20cabdff1aSopenharmony_ci */ 21cabdff1aSopenharmony_ci 22cabdff1aSopenharmony_ci#include "libavutil/intreadwrite.h" 23cabdff1aSopenharmony_ci#include "avformat.h" 24cabdff1aSopenharmony_ci#include "rawdec.h" 25cabdff1aSopenharmony_ci 26cabdff1aSopenharmony_cistatic int h261_probe(const AVProbeData *p) 27cabdff1aSopenharmony_ci{ 28cabdff1aSopenharmony_ci int i; 29cabdff1aSopenharmony_ci int valid_psc=0; 30cabdff1aSopenharmony_ci int invalid_psc=0; 31cabdff1aSopenharmony_ci int next_gn=0; 32cabdff1aSopenharmony_ci int src_fmt=0; 33cabdff1aSopenharmony_ci 34cabdff1aSopenharmony_ci for(i=0; i<p->buf_size; i++){ 35cabdff1aSopenharmony_ci if ((AV_RB16(&p->buf[i]) - 1) < 0xFFU) { 36cabdff1aSopenharmony_ci int shift = av_log2_16bit(p->buf[i+1]); 37cabdff1aSopenharmony_ci uint32_t code = AV_RB64(&p->buf[FFMAX(i-1, 0)]) >> (24+shift); 38cabdff1aSopenharmony_ci if ((code & 0xffff0000) == 0x10000) { 39cabdff1aSopenharmony_ci int gn= (code>>12)&0xf; 40cabdff1aSopenharmony_ci if(!gn) 41cabdff1aSopenharmony_ci src_fmt= code&8; 42cabdff1aSopenharmony_ci if(gn != next_gn) invalid_psc++; 43cabdff1aSopenharmony_ci else valid_psc++; 44cabdff1aSopenharmony_ci 45cabdff1aSopenharmony_ci if(src_fmt){ // CIF 46cabdff1aSopenharmony_ci static const int lut[16]={1,2,3,4,5,6,7,8,9,10,11,12,0,16,16,16}; 47cabdff1aSopenharmony_ci next_gn = lut[gn]; 48cabdff1aSopenharmony_ci }else{ //QCIF 49cabdff1aSopenharmony_ci static const int lut[16]={1,3,16,5,16,0,16,16,16,16,16,16,16,16,16,16}; 50cabdff1aSopenharmony_ci next_gn = lut[gn]; 51cabdff1aSopenharmony_ci } 52cabdff1aSopenharmony_ci } 53cabdff1aSopenharmony_ci } 54cabdff1aSopenharmony_ci } 55cabdff1aSopenharmony_ci if(valid_psc > 2*invalid_psc + 6){ 56cabdff1aSopenharmony_ci return AVPROBE_SCORE_EXTENSION; 57cabdff1aSopenharmony_ci }else if(valid_psc > 2*invalid_psc + 2) 58cabdff1aSopenharmony_ci return AVPROBE_SCORE_EXTENSION / 2; 59cabdff1aSopenharmony_ci return 0; 60cabdff1aSopenharmony_ci} 61cabdff1aSopenharmony_ci 62cabdff1aSopenharmony_ciFF_DEF_RAWVIDEO_DEMUXER(h261, "raw H.261", h261_probe, "h261", AV_CODEC_ID_H261) 63