3 * Copyright (c) 2012 Paul B Mahol
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/intreadwrite.h"
27 static int avr_probe(AVProbeData *p)
29 if (AV_RL32(p->buf) == MKTAG('2', 'B', 'I', 'T'))
30 return AVPROBE_SCORE_MAX / 2;
34 static int avr_read_header(AVFormatContext *s)
36 uint16_t chan, sign, bps;
39 st = avformat_new_stream(s, NULL);
41 return AVERROR(ENOMEM);
43 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
45 avio_skip(s->pb, 4); // magic
46 avio_skip(s->pb, 8); // sample_name
48 chan = avio_rb16(s->pb);
50 st->codec->channels = 1;
51 } else if (chan == 0xFFFFu) {
52 st->codec->channels = 2;
54 av_log_ask_for_sample(s, "unknown number of channels\n");
55 return AVERROR_PATCHWELCOME;
58 st->codec->bits_per_coded_sample = bps = avio_rb16(s->pb);
60 sign = avio_rb16(s->pb);
62 avio_skip(s->pb, 2); // loop
63 avio_skip(s->pb, 2); // midi
64 avio_skip(s->pb, 1); // replay speed
66 st->codec->sample_rate = avio_rb24(s->pb);
67 avio_skip(s->pb, 4 * 3);
68 avio_skip(s->pb, 2 * 3);
72 if (!sign && bps == 8) {
73 st->codec->codec_id = AV_CODEC_ID_PCM_U8;
74 } else if (!sign && bps == 16) {
75 st->codec->codec_id = AV_CODEC_ID_PCM_U16BE;
76 } else if (sign == 0xFFFFu && bps == 8) {
77 st->codec->codec_id = AV_CODEC_ID_PCM_S8;
78 } else if (sign == 0xFFFFu && bps == 16) {
79 st->codec->codec_id = AV_CODEC_ID_PCM_S16BE;
81 av_log_ask_for_sample(s, "unknown bits per sample\n");
82 return AVERROR_PATCHWELCOME;
85 st->codec->block_align = bps * st->codec->channels / 8;
87 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
91 AVInputFormat ff_avr_demuxer = {
93 .long_name = NULL_IF_CONFIG_SMALL("AVR (Audio Visual Research)"),
94 .read_probe = avr_probe,
95 .read_header = avr_read_header,
96 .read_packet = ff_pcm_read_packet,
97 .read_seek = ff_pcm_read_seek,
99 .flags = AVFMT_GENERIC_INDEX,