yading@11: /*
yading@11:  * CD Graphics Demuxer
yading@11:  * Copyright (c) 2009 Michael Tison
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: 
yading@11: #define CDG_PACKET_SIZE    24
yading@11: #define CDG_COMMAND        0x09
yading@11: #define CDG_MASK           0x3F
yading@11: 
yading@11: static int read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVStream *vst;
yading@11:     int ret;
yading@11: 
yading@11:     vst = avformat_new_stream(s, NULL);
yading@11:     if (!vst)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     vst->codec->codec_id   = AV_CODEC_ID_CDGRAPHICS;
yading@11: 
yading@11:     /// 75 sectors/sec * 4 packets/sector = 300 packets/sec
yading@11:     avpriv_set_pts_info(vst, 32, 1, 300);
yading@11: 
yading@11:     ret = avio_size(s->pb);
yading@11:     if (ret > 0)
yading@11:         vst->duration = (ret * vst->time_base.den) / (CDG_PACKET_SIZE * 300);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     int ret;
yading@11: 
yading@11:     while (1) {
yading@11:         ret = av_get_packet(s->pb, pkt, CDG_PACKET_SIZE);
yading@11:         if (ret < 1 || (pkt->data[0] & CDG_MASK) == CDG_COMMAND)
yading@11:             break;
yading@11:         av_free_packet(pkt);
yading@11:     }
yading@11: 
yading@11:     pkt->stream_index = 0;
yading@11:     pkt->dts=
yading@11:     pkt->pts= pkt->pos / CDG_PACKET_SIZE;
yading@11: 
yading@11:     if(ret>5 && (pkt->data[0]&0x3F) == 9 && (pkt->data[1]&0x3F)==1 && !(pkt->data[2+2+1] & 0x0F)){
yading@11:         pkt->flags = AV_PKT_FLAG_KEY;
yading@11:     }
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_cdg_demuxer = {
yading@11:     .name           = "cdg",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("CD Graphics"),
yading@11:     .read_header    = read_header,
yading@11:     .read_packet    = read_packet,
yading@11:     .flags          = AVFMT_GENERIC_INDEX,
yading@11:     .extensions     = "cdg",
yading@11: };