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libavformat
cdg.c
Go to the documentation of this file.
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/*
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* CD Graphics Demuxer
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* Copyright (c) 2009 Michael Tison
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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 "
internal.h
"
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#define CDG_PACKET_SIZE 24
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#define CDG_COMMAND 0x09
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#define CDG_MASK 0x3F
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static
int
read_header
(
AVFormatContext
*
s
)
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{
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AVStream
*vst;
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int
ret
;
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vst =
avformat_new_stream
(s, NULL);
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if
(!vst)
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return
AVERROR
(ENOMEM);
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vst->
codec
->
codec_type
=
AVMEDIA_TYPE_VIDEO
;
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vst->
codec
->
codec_id
=
AV_CODEC_ID_CDGRAPHICS
;
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/// 75 sectors/sec * 4 packets/sector = 300 packets/sec
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avpriv_set_pts_info
(vst, 32, 1, 300);
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ret =
avio_size
(s->
pb
);
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if
(ret > 0)
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vst->
duration
= (ret * vst->
time_base
.
den
) / (
CDG_PACKET_SIZE
* 300);
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return
0;
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}
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static
int
read_packet
(
AVFormatContext
*
s
,
AVPacket
*
pkt
)
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{
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int
ret
;
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while
(1) {
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ret =
av_get_packet
(s->
pb
, pkt,
CDG_PACKET_SIZE
);
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if
(ret < 1 || (pkt->
data
[0] &
CDG_MASK
) ==
CDG_COMMAND
)
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break
;
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av_free_packet
(pkt);
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}
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pkt->
stream_index
= 0;
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pkt->
dts
=
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pkt->
pts
= pkt->
pos
/
CDG_PACKET_SIZE
;
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if
(ret>5 && (pkt->
data
[0]&0x3F) == 9 && (pkt->
data
[1]&0x3F)==1 && !(pkt->
data
[2+2+1] & 0x0F)){
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pkt->
flags
=
AV_PKT_FLAG_KEY
;
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}
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return
ret
;
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}
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AVInputFormat
ff_cdg_demuxer
= {
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.
name
=
"cdg"
,
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.long_name =
NULL_IF_CONFIG_SMALL
(
"CD Graphics"
),
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.read_header =
read_header
,
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.read_packet =
read_packet
,
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.flags =
AVFMT_GENERIC_INDEX
,
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.extensions =
"cdg"
,
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};
Generated on Wed Jul 10 2013 23:48:11 for FFmpeg by
1.8.2