1/* 2 * Metar Gear Solid: The Twin Snakes demuxer 3 * Copyright (c) 2012 Paul B Mahol 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 "libavutil/intreadwrite.h" 23#include "libavutil/intfloat.h" 24#include "avformat.h" 25#include "riff.h" 26 27static int read_probe(AVProbeData *p) 28{ 29 if (AV_RB32(p->buf ) != 0x000E || 30 AV_RB32(p->buf + 4) != 0x0050 || 31 AV_RB32(p->buf + 12) != 0x0034) 32 return 0; 33 return AVPROBE_SCORE_MAX; 34} 35 36static int read_header(AVFormatContext *s) 37{ 38 AVIOContext *pb = s->pb; 39 AVStream *st; 40 AVRational fps; 41 uint32_t chunk_size; 42 43 avio_skip(pb, 4); 44 chunk_size = avio_rb32(pb); 45 if (chunk_size != 80) 46 return AVERROR(EIO); 47 avio_skip(pb, 20); 48 49 st = avformat_new_stream(s, 0); 50 if (!st) 51 return AVERROR(ENOMEM); 52 53 st->need_parsing = AVSTREAM_PARSE_HEADERS; 54 st->start_time = 0; 55 st->nb_frames = 56 st->duration = avio_rb32(pb); 57 fps = av_d2q(av_int2float(avio_rb32(pb)), INT_MAX); 58 st->codec->width = avio_rb32(pb); 59 st->codec->height = avio_rb32(pb); 60 avio_skip(pb, 12); 61 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 62 st->codec->codec_tag = avio_rb32(pb); 63 st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, 64 st->codec->codec_tag); 65 avpriv_set_pts_info(st, 64, fps.den, fps.num); 66 avio_skip(pb, 20); 67 68 return 0; 69} 70 71static int read_packet(AVFormatContext *s, AVPacket *pkt) 72{ 73 AVIOContext *pb = s->pb; 74 uint32_t chunk_size, payload_size; 75 int ret; 76 77 if (url_feof(pb)) 78 return AVERROR_EOF; 79 80 avio_skip(pb, 4); 81 chunk_size = avio_rb32(pb); 82 avio_skip(pb, 4); 83 payload_size = avio_rb32(pb); 84 85 if (chunk_size < payload_size + 16) 86 return AVERROR(EIO); 87 88 ret = av_get_packet(pb, pkt, payload_size); 89 if (ret < 0) 90 return ret; 91 92 pkt->pos -= 16; 93 pkt->duration = 1; 94 avio_skip(pb, chunk_size - (ret + 16)); 95 96 return ret; 97} 98 99AVInputFormat ff_mgsts_demuxer = { 100 .name = "mgsts", 101 .long_name = NULL_IF_CONFIG_SMALL("Metal Gear Solid: The Twin Snakes"), 102 .read_probe = read_probe, 103 .read_header = read_header, 104 .read_packet = read_packet, 105 .flags = AVFMT_GENERIC_INDEX, 106}; 107