1/* 2 * CD Graphics Demuxer 3 * Copyright (c) 2009 Michael Tison 4 * 5 * This file is part of FFmpeg. 6 * 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. 11 * 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. 16 * 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 20 */ 21 22#include "avformat.h" 23 24#define CDG_PACKET_SIZE 24 25 26static int read_header(AVFormatContext *s, AVFormatParameters *ap) 27{ 28 AVStream *vst; 29 int ret; 30 31 vst = av_new_stream(s, 0); 32 if (!vst) 33 return AVERROR(ENOMEM); 34 35 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; 36 vst->codec->codec_id = CODEC_ID_CDGRAPHICS; 37 38 /// 75 sectors/sec * 4 packets/sector = 300 packets/sec 39 av_set_pts_info(vst, 32, 1, 300); 40 41 ret = url_fsize(s->pb); 42 if (ret > 0) 43 vst->duration = (ret * vst->time_base.den) / (CDG_PACKET_SIZE * 300); 44 45 return 0; 46} 47 48static int read_packet(AVFormatContext *s, AVPacket *pkt) 49{ 50 int ret; 51 52 ret = av_get_packet(s->pb, pkt, CDG_PACKET_SIZE); 53 54 pkt->stream_index = 0; 55 return ret; 56} 57 58AVInputFormat cdg_demuxer = { 59 "cdg", 60 NULL_IF_CONFIG_SMALL("CD Graphics Format"), 61 0, 62 NULL, 63 read_header, 64 read_packet, 65 .extensions = "cdg" 66}; 67