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libavformat
mpegvideodec.c
Go to the documentation of this file.
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/*
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* RAW MPEG video demuxer
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* Copyright (c) 2002-2003 Fabrice Bellard
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* Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "
avformat.h
"
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#include "
rawdec.h
"
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#define SEQ_START_CODE 0x000001b3
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#define GOP_START_CODE 0x000001b8
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#define PICTURE_START_CODE 0x00000100
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#define SLICE_START_CODE 0x00000101
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#define PACK_START_CODE 0x000001ba
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#define VIDEO_ID 0x000001e0
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#define AUDIO_ID 0x000001c0
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static
int
mpegvideo_probe
(
AVProbeData
*p)
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{
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uint32_t code= -1;
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int
pic=0, seq=0, slice=0, pspack=0, pes=0;
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int
i;
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for
(i=0; i<p->
buf_size
; i++){
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code = (code<<8) + p->
buf
[i];
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if ((code & 0xffffff00) == 0x100) {
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switch
(code){
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case
SEQ_START_CODE
: seq++;
break
;
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case
PICTURE_START_CODE
: pic++;
break
;
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case
SLICE_START_CODE
: slice++;
break
;
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case
PACK_START_CODE
: pspack++;
break
;
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}
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if
((code & 0x1f0) ==
VIDEO_ID
) pes++;
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else
if
((code & 0x1e0) ==
AUDIO_ID
) pes++;
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}
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}
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if
(seq && seq*9<=pic*10 && pic*9<=slice*10 && !pspack && !pes)
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return
pic>1 ?
AVPROBE_SCORE_MAX
/2+1 :
AVPROBE_SCORE_MAX
/4;
// +1 for .mpg
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return
0;
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}
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FF_DEF_RAWVIDEO_DEMUXER
(mpegvideo,
"raw MPEG video"
,
mpegvideo_probe
,
NULL
,
CODEC_ID_MPEG1VIDEO
)