| /* |
| * 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", |
| }; |