xref: /third_party/ffmpeg/libavformat/vag.c (revision cabdff1a)
1/*
2 * VAG demuxer
3 * Copyright (c) 2015 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/channel_layout.h"
23#include "avformat.h"
24#include "internal.h"
25
26static int vag_probe(const AVProbeData *p)
27{
28    if (memcmp(p->buf, "VAGp\0\0\0", 7))
29        return 0;
30
31    return AVPROBE_SCORE_MAX;
32}
33
34static int vag_read_header(AVFormatContext *s)
35{
36    AVStream *st;
37
38    st = avformat_new_stream(s, NULL);
39    if (!st)
40        return AVERROR(ENOMEM);
41
42    avio_skip(s->pb, 4);
43    st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
44    st->codecpar->codec_id    = AV_CODEC_ID_ADPCM_PSX;
45    st->codecpar->ch_layout.nb_channels = 1 + (avio_rb32(s->pb) == 0x00000004);
46    avio_skip(s->pb, 4);
47    if (st->codecpar->ch_layout.nb_channels > 1) {
48        st->duration       = avio_rb32(s->pb);
49    } else {
50        st->duration       = avio_rb32(s->pb) / 16 * 28;
51    }
52    st->codecpar->sample_rate = avio_rb32(s->pb);
53    if (st->codecpar->sample_rate <= 0)
54        return AVERROR_INVALIDDATA;
55    avio_seek(s->pb, 0x1000, SEEK_SET);
56    if (avio_rl32(s->pb) == MKTAG('V','A','G','p')) {
57        st->codecpar->block_align = 0x1000 * st->codecpar->ch_layout.nb_channels;
58        avio_seek(s->pb, 0, SEEK_SET);
59        st->duration = st->duration / 16 * 28;
60    } else {
61        st->codecpar->block_align = 16 * st->codecpar->ch_layout.nb_channels;
62        avio_seek(s->pb, st->codecpar->ch_layout.nb_channels > 1 ? 0x80 : 0x30, SEEK_SET);
63    }
64    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
65
66    return 0;
67}
68
69static int vag_read_packet(AVFormatContext *s, AVPacket *pkt)
70{
71    AVCodecParameters *par = s->streams[0]->codecpar;
72
73    return av_get_packet(s->pb, pkt, par->block_align);
74}
75
76const AVInputFormat ff_vag_demuxer = {
77    .name           = "vag",
78    .long_name      = NULL_IF_CONFIG_SMALL("Sony PS2 VAG"),
79    .read_probe     = vag_probe,
80    .read_header    = vag_read_header,
81    .read_packet    = vag_read_packet,
82    .extensions     = "vag",
83};
84