1/*
2 * AVR 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 "avformat.h"
24#include "internal.h"
25#include "pcm.h"
26
27static int avr_probe(AVProbeData *p)
28{
29    if (AV_RL32(p->buf) != MKTAG('2', 'B', 'I', 'T'))
30        return 0;
31
32    if (!AV_RB16(p->buf+12) || AV_RB16(p->buf+12) > 256) // channels
33        return AVPROBE_SCORE_EXTENSION/2;
34    if (AV_RB16(p->buf+14) > 256) // bps
35        return AVPROBE_SCORE_EXTENSION/2;
36
37    return AVPROBE_SCORE_EXTENSION;
38}
39
40static int avr_read_header(AVFormatContext *s)
41{
42    uint16_t chan, sign, bps;
43    AVStream *st;
44
45    st = avformat_new_stream(s, NULL);
46    if (!st)
47        return AVERROR(ENOMEM);
48
49    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
50
51    avio_skip(s->pb, 4); // magic
52    avio_skip(s->pb, 8); // sample_name
53
54    chan = avio_rb16(s->pb);
55    if (!chan) {
56        st->codec->channels = 1;
57    } else if (chan == 0xFFFFu) {
58        st->codec->channels = 2;
59    } else {
60        avpriv_request_sample(s, "chan %d", chan);
61        return AVERROR_PATCHWELCOME;
62    }
63
64    st->codec->bits_per_coded_sample = bps = avio_rb16(s->pb);
65
66    sign = avio_rb16(s->pb);
67
68    avio_skip(s->pb, 2); // loop
69    avio_skip(s->pb, 2); // midi
70    avio_skip(s->pb, 1); // replay speed
71
72    st->codec->sample_rate = avio_rb24(s->pb);
73    avio_skip(s->pb, 4 * 3);
74    avio_skip(s->pb, 2 * 3);
75    avio_skip(s->pb, 20);
76    avio_skip(s->pb, 64);
77
78    st->codec->codec_id = ff_get_pcm_codec_id(bps, 0, 1, sign);
79    if (st->codec->codec_id == AV_CODEC_ID_NONE) {
80        avpriv_request_sample(s, "Bps %d and sign %d", bps, sign);
81        return AVERROR_PATCHWELCOME;
82    }
83
84    st->codec->block_align = bps * st->codec->channels / 8;
85
86    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
87    return 0;
88}
89
90AVInputFormat ff_avr_demuxer = {
91    .name           = "avr",
92    .long_name      = NULL_IF_CONFIG_SMALL("AVR (Audio Visual Research)"),
93    .read_probe     = avr_probe,
94    .read_header    = avr_read_header,
95    .read_packet    = ff_pcm_read_packet,
96    .read_seek      = ff_pcm_read_seek,
97    .extensions     = "avr",
98    .flags          = AVFMT_GENERIC_INDEX,
99};
100