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