CRYO APC demuxer
[libav.git] / libavformat / apc.c
CommitLineData
8e952e4d
AH
1/*
2 * CRYO APC audio format demuxer
3 * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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 "avformat.h"
23#include "string.h"
24
25static int apc_probe(AVProbeData *p)
26{
27 if (p->buf_size < 8)
28 return 0;
29
30 if (!strncmp(p->buf, "CRYO_APC", 8))
31 return AVPROBE_SCORE_MAX;
32
33 return 0;
34}
35
36static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap)
37{
38 ByteIOContext *pb = &s->pb;
39 AVStream *st;
40
41 get_le32(pb); /* CRYO */
42 get_le32(pb); /* _APC */
43 get_le32(pb); /* 1.20 */
44
45 st = av_new_stream(s, 0);
46 if (!st)
47 return AVERROR_NOMEM;
48
49 st->codec->codec_type = CODEC_TYPE_AUDIO;
50 st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
51
52 get_le32(pb); /* number of samples */
53 st->codec->sample_rate = get_le32(pb);
54
55 st->codec->extradata_size = 2 * 4;
56 st->codec->extradata = av_malloc(st->codec->extradata_size +
57 FF_INPUT_BUFFER_PADDING_SIZE);
58 if (!st->codec->extradata)
59 return AVERROR_NOMEM;
60
61 /* initial predictor values for adpcm decoder */
62 get_buffer(pb, st->codec->extradata, 2 * 4);
63
64 st->codec->channels = 1;
65 if (get_le32(pb))
66 st->codec->channels = 2;
67
68 st->codec->bits_per_sample = 4;
69 st->codec->bit_rate = st->codec->bits_per_sample * st->codec->channels
70 * st->codec->sample_rate;
71 st->codec->block_align = 1;
72
73 return 0;
74}
75
76#define MAX_READ_SIZE 4096
77
78static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
79{
80 if (av_get_packet(&s->pb, pkt, MAX_READ_SIZE) <= 0)
81 return AVERROR_IO;
82 pkt->stream_index = 0;
83 return 0;
84}
85
86AVInputFormat apc_demuxer = {
87 "apc",
88 "CRYO APC format",
89 0,
90 apc_probe,
91 apc_read_header,
92 apc_read_packet,
93};