mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
e1da139a33
Also in cdg demuxer do not skip packets data, and remove private context which is not really needed.
78 lines
2.3 KiB
C
78 lines
2.3 KiB
C
/*
|
|
* CD Graphics Demuxer
|
|
* Copyright (c) 2009 Michael Tison
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "avformat.h"
|
|
#include "internal.h"
|
|
|
|
#define CDG_PACKET_SIZE 24
|
|
#define CDG_COMMAND 0x09
|
|
#define CDG_MASK 0x3F
|
|
|
|
static int read_header(AVFormatContext *s)
|
|
{
|
|
AVStream *vst;
|
|
int ret;
|
|
|
|
vst = avformat_new_stream(s, NULL);
|
|
if (!vst)
|
|
return AVERROR(ENOMEM);
|
|
|
|
vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
|
|
vst->codecpar->codec_id = AV_CODEC_ID_CDGRAPHICS;
|
|
|
|
/// 75 sectors/sec * 4 packets/sector = 300 packets/sec
|
|
avpriv_set_pts_info(vst, 32, 1, 300);
|
|
|
|
ret = avio_size(s->pb);
|
|
if (ret < 0) {
|
|
av_log(s, AV_LOG_WARNING, "Cannot calculate duration as file size cannot be determined\n");
|
|
} else
|
|
vst->duration = (ret * (int64_t)vst->time_base.den) / (CDG_PACKET_SIZE * 300);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int read_packet(AVFormatContext *s, AVPacket *pkt)
|
|
{
|
|
int ret;
|
|
|
|
ret = av_get_packet(s->pb, pkt, CDG_PACKET_SIZE);
|
|
pkt->stream_index = 0;
|
|
pkt->dts=
|
|
pkt->pts= pkt->pos / CDG_PACKET_SIZE;
|
|
|
|
if (!pkt->pos || (ret > 5 &&
|
|
(pkt->data[0] & CDG_MASK) == CDG_COMMAND &&
|
|
(pkt->data[1] & CDG_MASK) == 1 && !(pkt->data[2+2+1] & 0x0F))) {
|
|
pkt->flags = AV_PKT_FLAG_KEY;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
AVInputFormat ff_cdg_demuxer = {
|
|
.name = "cdg",
|
|
.long_name = NULL_IF_CONFIG_SMALL("CD Graphics"),
|
|
.read_header = read_header,
|
|
.read_packet = read_packet,
|
|
.flags = AVFMT_GENERIC_INDEX,
|
|
.extensions = "cdg",
|
|
};
|