3 * Copyright (c) 2009 Michael Tison
5 * This file is part of FFmpeg.
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.
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.
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
25 #define CDG_PACKET_SIZE 24
26 #define CDG_COMMAND 0x09
29 typedef struct CDGContext
{
33 static int read_header(AVFormatContext
*s
)
38 vst
= avformat_new_stream(s
, NULL
);
40 return AVERROR(ENOMEM
);
42 vst
->codec
->codec_type
= AVMEDIA_TYPE_VIDEO
;
43 vst
->codec
->codec_id
= AV_CODEC_ID_CDGRAPHICS
;
45 /// 75 sectors/sec * 4 packets/sector = 300 packets/sec
46 avpriv_set_pts_info(vst
, 32, 1, 300);
48 ret
= avio_size(s
->pb
);
50 av_log(s
, AV_LOG_WARNING
, "Cannot calculate duration as file size cannot be determined\n");
52 vst
->duration
= (ret
* vst
->time_base
.den
) / (CDG_PACKET_SIZE
* 300);
57 static int read_packet(AVFormatContext
*s
, AVPacket
*pkt
)
59 CDGContext
*priv
= s
->priv_data
;
63 ret
= av_get_packet(s
->pb
, pkt
, CDG_PACKET_SIZE
);
64 if (ret
< 1 || (pkt
->data
[0] & CDG_MASK
) == CDG_COMMAND
)
69 if (!priv
->got_first_packet
) {
70 pkt
->flags
|= AV_PKT_FLAG_KEY
;
71 priv
->got_first_packet
= 1;
74 pkt
->stream_index
= 0;
76 pkt
->pts
= pkt
->pos
/ CDG_PACKET_SIZE
;
78 if(ret
>5 && (pkt
->data
[0]&0x3F) == 9 && (pkt
->data
[1]&0x3F)==1 && !(pkt
->data
[2+2+1] & 0x0F)){
79 pkt
->flags
= AV_PKT_FLAG_KEY
;
84 AVInputFormat ff_cdg_demuxer
= {
86 .long_name
= NULL_IF_CONFIG_SMALL("CD Graphics"),
87 .priv_data_size
= sizeof(CDGContext
),
88 .read_header
= read_header
,
89 .read_packet
= read_packet
,
90 .flags
= AVFMT_GENERIC_INDEX
,