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
read_probe(const AVProbeData * p)27 static int read_probe(const 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
read_header(AVFormatContext * s)36 static 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->codecpar->width = avio_rb32(pb);
59 st->codecpar->height = avio_rb32(pb);
60 avio_skip(pb, 12);
61 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
62 st->codecpar->codec_tag = avio_rb32(pb);
63 st->codecpar->codec_id = ff_codec_get_id(ff_codec_bmp_tags,
64 st->codecpar->codec_tag);
65 avpriv_set_pts_info(st, 64, fps.den, fps.num);
66 avio_skip(pb, 20);
67
68 return 0;
69 }
70
read_packet(AVFormatContext * s,AVPacket * pkt)71 static 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 (avio_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
99 AVInputFormat 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