repositories / deb_ffmpeg.git / blame
| Commit | Line | Data |
|---|---|---|
| 2ba45a60 DM |
1 | /* |
| 2 | * RAW H.261 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 "libavcodec/get_bits.h" | |
| 23 | #include "avformat.h" | |
| 24 | #include "rawdec.h" | |
| 25 | ||
| 26 | static int h261_probe(AVProbeData *p) | |
| 27 | { | |
| 28 | int i; | |
| 29 | int valid_psc=0; | |
| 30 | int invalid_psc=0; | |
| 31 | int next_gn=0; | |
| 32 | int src_fmt=0; | |
| 33 | ||
| 34 | for(i=0; i<p->buf_size; i++){ | |
| 35 | if ((AV_RB16(&p->buf[i]) - 1) < 0xFFU) { | |
| 36 | int shift = av_log2_16bit(p->buf[i+1]); | |
| 37 | uint32_t code = AV_RB64(&p->buf[FFMAX(i-1, 0)]) >> (24+shift); | |
| 38 | if ((code & 0xffff0000) == 0x10000) { | |
| 39 | int gn= (code>>12)&0xf; | |
| 40 | if(!gn) | |
| 41 | src_fmt= code&8; | |
| 42 | if(gn != next_gn) invalid_psc++; | |
| 43 | else valid_psc++; | |
| 44 | ||
| 45 | if(src_fmt){ // CIF | |
| 46 | static const int lut[16]={1,2,3,4,5,6,7,8,9,10,11,12,0,16,16,16}; | |
| 47 | next_gn = lut[gn]; | |
| 48 | }else{ //QCIF | |
| 49 | static const int lut[16]={1,3,16,5,16,0,16,16,16,16,16,16,16,16,16,16}; | |
| 50 | next_gn = lut[gn]; | |
| 51 | } | |
| 52 | } | |
| 53 | } | |
| 54 | } | |
| 55 | if(valid_psc > 2*invalid_psc + 6){ | |
| 56 | return AVPROBE_SCORE_EXTENSION; | |
| 57 | }else if(valid_psc > 2*invalid_psc + 2) | |
| 58 | return AVPROBE_SCORE_EXTENSION / 2; | |
| 59 | return 0; | |
| 60 | } | |
| 61 | ||
| 62 | FF_DEF_RAWVIDEO_DEMUXER(h261, "raw H.261", h261_probe, "h261", AV_CODEC_ID_H261) |