Skip to content
Snippets Groups Projects
cdg.c 1.7 KiB
Newer Older
  • Learn to ignore specific revisions
  • Michael Tison's avatar
    Michael Tison committed
    /*
     * 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"
    
    #define CDG_PACKET_SIZE    24
    
    static int read_header(AVFormatContext *s, AVFormatParameters *ap)
    {
        AVStream *vst;
        int ret;
    
        vst = av_new_stream(s, 0);
        if (!vst)
            return AVERROR(ENOMEM);
    
        vst->codec->codec_type = CODEC_TYPE_VIDEO;
        vst->codec->codec_id   = CODEC_ID_CDGRAPHICS;
    
        /// 75 sectors/sec * 4 packets/sector = 300 packets/sec
        av_set_pts_info(vst, 32, 1, 300);
    
        ret = url_fsize(s->pb);
        if (ret > 0)
            vst->duration = (ret * 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;
        return ret;
    }
    
    AVInputFormat cdg_demuxer = {
        "cdg",
        NULL_IF_CONFIG_SMALL("CD Graphics Format"),
        0,
        NULL,
        read_header,
        read_packet,
        .extensions = "cdg"
    };