ffmpeg / libavformat / h263dec.c @ 4dcde00c
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| 1 | b30593c7 | Aurelien Jacobs | /*
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| 2 | * RAW H.263 video demuxer
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| 3 | * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at>
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| 4 | *
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| 5 | 2912e87a | Mans Rullgard | * This file is part of Libav.
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| 6 | b30593c7 | Aurelien Jacobs | *
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| 7 | 2912e87a | Mans Rullgard | * Libav is free software; you can redistribute it and/or
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| 8 | b30593c7 | Aurelien Jacobs | * modify it under the terms of the GNU Lesser General Public
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| 9 | * License as published by the Free Software Foundation; either
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| 10 | * version 2.1 of the License, or (at your option) any later version.
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| 11 | *
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| 12 | 2912e87a | Mans Rullgard | * Libav is distributed in the hope that it will be useful,
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| 13 | b30593c7 | Aurelien Jacobs | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 15 | * Lesser General Public License for more details.
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| 16 | *
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| 17 | * You should have received a copy of the GNU Lesser General Public
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| 18 | 2912e87a | Mans Rullgard | * License along with Libav; if not, write to the Free Software
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| 19 | b30593c7 | Aurelien Jacobs | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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| 20 | */
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| 21 | |||
| 22 | #include "avformat.h" |
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| 23 | 4ca31edc | Aurelien Jacobs | #include "rawdec.h" |
| 24 | b30593c7 | Aurelien Jacobs | |
| 25 | static int h263_probe(AVProbeData *p) |
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| 26 | {
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| 27 | uint64_t code= -1;
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| 28 | int i;
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| 29 | int valid_psc=0; |
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| 30 | int invalid_psc=0; |
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| 31 | int res_change=0; |
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| 32 | int src_fmt, last_src_fmt=-1; |
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| 33 | int last_gn=0; |
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| 34 | |||
| 35 | for(i=0; i<p->buf_size; i++){ |
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| 36 | code = (code<<8) + p->buf[i];
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| 37 | if ((code & 0xfffffc0000) == 0x800000) { |
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| 38 | src_fmt= (code>>2)&3; |
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| 39 | if( src_fmt != last_src_fmt
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| 40 | && last_src_fmt>0 && last_src_fmt<6 |
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| 41 | && src_fmt<6)
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| 42 | res_change++; |
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| 43 | |||
| 44 | if((code&0x300)==0x200 && src_fmt){ |
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| 45 | valid_psc++; |
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| 46 | last_gn=0;
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| 47 | }else
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| 48 | invalid_psc++; |
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| 49 | last_src_fmt= src_fmt; |
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| 50 | } else if((code & 0xffff800000) == 0x800000) { |
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| 51 | int gn= (code>>(23-5)) & 0x1F; |
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| 52 | if(gn<last_gn){
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| 53 | invalid_psc++; |
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| 54 | }else
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| 55 | last_gn= gn; |
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| 56 | } |
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| 57 | } |
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| 58 | //av_log(NULL, AV_LOG_ERROR, "h263_probe: psc:%d invalid:%d res_change:%d\n", valid_psc, invalid_psc, res_change);
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| 59 | //h263_probe: psc:3 invalid:0 res_change:0 (1588/recent_ffmpeg_parses_mpg_incorrectly.mpg)
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| 60 | if(valid_psc > 2*invalid_psc + 2*res_change + 3){ |
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| 61 | return 50; |
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| 62 | }else if(valid_psc > 2*invalid_psc) |
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| 63 | return 25; |
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| 64 | return 0; |
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| 65 | } |
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| 66 | |||
| 67 | c6610a21 | Diego Elio Pettenò | AVInputFormat ff_h263_demuxer = {
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| 68 | b30593c7 | Aurelien Jacobs | "h263",
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| 69 | NULL_IF_CONFIG_SMALL("raw H.263"),
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| 70 | 0,
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| 71 | h263_probe, |
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| 72 | ff_raw_video_read_header, |
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| 73 | ff_raw_read_partial_packet, |
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| 74 | .flags= AVFMT_GENERIC_INDEX, |
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| 75 | // .extensions = "h263", //FIXME remove after writing mpeg4_probe
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| 76 | .value = CODEC_ID_H263, |
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| 77 | }; |