1/* 2 * RAW H.263 video demuxer 3 * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 int tr, last_tr = -1; 35 36 for(i=0; i<p->buf_size; i++){ 37 code = (code<<8) + p->buf[i]; 38 if ((code & 0xfffffc000000) == 0x80000000) { 39 tr = (code >> 18) & 0xFF; 40 src_fmt= (code>>10)&7; 41 if( src_fmt != last_src_fmt 42 && last_src_fmt>0 && last_src_fmt<6 43 && src_fmt<6) 44 res_change++; 45 46 if (tr == last_tr) { 47 invalid_psc++; 48 continue; 49 } 50 51 if (src_fmt != 7 && !(code&(1<<9)) && (code&(1<<5))) { 52 invalid_psc++; 53 continue; 54 } 55 56 if((code&0x30000)==0x20000 && src_fmt){ 57 valid_psc++; 58 last_gn=0; 59 }else 60 invalid_psc++; 61 last_src_fmt= src_fmt; 62 last_tr = tr; 63 } else if((code & 0xffff80000000) == 0x80000000) { 64 int gn= (code>>(31-5)) & 0x1F; 65 if(gn<last_gn){ 66 invalid_psc++; 67 }else 68 last_gn= gn; 69 } 70 } 71 if(valid_psc > 2*invalid_psc + 2*res_change + 3){ 72 return AVPROBE_SCORE_EXTENSION; 73 }else if(valid_psc > 2*invalid_psc) 74 return AVPROBE_SCORE_EXTENSION / 2; 75 return 0; 76} 77 78FF_DEF_RAWVIDEO_DEMUXER(h263, "raw H.263", h263_probe, NULL, AV_CODEC_ID_H263) 79