yading@11: /*
yading@11:  * Metar Gear Solid: The Twin Snakes demuxer
yading@11:  * Copyright (c) 2012 Paul B Mahol
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 "libavutil/intreadwrite.h"
yading@11: #include "libavutil/intfloat.h"
yading@11: #include "avformat.h"
yading@11: #include "riff.h"
yading@11: 
yading@11: static int read_probe(AVProbeData *p)
yading@11: {
yading@11:     if (AV_RB32(p->buf     ) != 0x000E ||
yading@11:         AV_RB32(p->buf +  4) != 0x0050 ||
yading@11:         AV_RB32(p->buf + 12) != 0x0034)
yading@11:         return 0;
yading@11:     return AVPROBE_SCORE_MAX;
yading@11: }
yading@11: 
yading@11: static int read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVStream    *st;
yading@11:     AVRational  fps;
yading@11:     uint32_t chunk_size;
yading@11: 
yading@11:     avio_skip(pb, 4);
yading@11:     chunk_size = avio_rb32(pb);
yading@11:     if (chunk_size != 80)
yading@11:         return AVERROR(EIO);
yading@11:     avio_skip(pb, 20);
yading@11: 
yading@11:     st = avformat_new_stream(s, 0);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     st->need_parsing = AVSTREAM_PARSE_HEADERS;
yading@11:     st->start_time = 0;
yading@11:     st->nb_frames  =
yading@11:     st->duration   = avio_rb32(pb);
yading@11:     fps = av_d2q(av_int2float(avio_rb32(pb)), INT_MAX);
yading@11:     st->codec->width  = avio_rb32(pb);
yading@11:     st->codec->height = avio_rb32(pb);
yading@11:     avio_skip(pb, 12);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     st->codec->codec_tag  = avio_rb32(pb);
yading@11:     st->codec->codec_id   = ff_codec_get_id(ff_codec_bmp_tags,
yading@11:                                             st->codec->codec_tag);
yading@11:     avpriv_set_pts_info(st, 64, fps.den, fps.num);
yading@11:     avio_skip(pb, 20);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     uint32_t chunk_size, payload_size;
yading@11:     int ret;
yading@11: 
yading@11:     if (url_feof(pb))
yading@11:         return AVERROR_EOF;
yading@11: 
yading@11:     avio_skip(pb, 4);
yading@11:     chunk_size = avio_rb32(pb);
yading@11:     avio_skip(pb, 4);
yading@11:     payload_size = avio_rb32(pb);
yading@11: 
yading@11:     if (chunk_size < payload_size + 16)
yading@11:         return AVERROR(EIO);
yading@11: 
yading@11:     ret = av_get_packet(pb, pkt, payload_size);
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11: 
yading@11:     pkt->pos -= 16;
yading@11:     pkt->duration = 1;
yading@11:     avio_skip(pb, chunk_size - (ret + 16));
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_mgsts_demuxer = {
yading@11:     .name        = "mgsts",
yading@11:     .long_name   = NULL_IF_CONFIG_SMALL("Metal Gear Solid: The Twin Snakes"),
yading@11:     .read_probe  = read_probe,
yading@11:     .read_header = read_header,
yading@11:     .read_packet = read_packet,
yading@11:     .flags       = AVFMT_GENERIC_INDEX,
yading@11: };