238395087c5bacdf3a716657cf86a43dfec8d7db
[libav.git] / libavformat / apc.c
1 /*
2 * CRYO APC audio format demuxer
3 * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <string.h>
23 #include "avformat.h"
24
25 static int apc_probe(AVProbeData *p)
26 {
27 if (!strncmp(p->buf, "CRYO_APC", 8))
28 return AVPROBE_SCORE_MAX;
29
30 return 0;
31 }
32
33 static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap)
34 {
35 AVIOContext *pb = s->pb;
36 AVStream *st;
37
38 avio_rl32(pb); /* CRYO */
39 avio_rl32(pb); /* _APC */
40 avio_rl32(pb); /* 1.20 */
41
42 st = avformat_new_stream(s, NULL);
43 if (!st)
44 return AVERROR(ENOMEM);
45
46 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
47 st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
48
49 avio_rl32(pb); /* number of samples */
50 st->codec->sample_rate = avio_rl32(pb);
51
52 st->codec->extradata_size = 2 * 4;
53 st->codec->extradata = av_malloc(st->codec->extradata_size +
54 FF_INPUT_BUFFER_PADDING_SIZE);
55 if (!st->codec->extradata)
56 return AVERROR(ENOMEM);
57
58 /* initial predictor values for adpcm decoder */
59 avio_read(pb, st->codec->extradata, 2 * 4);
60
61 st->codec->channels = 1;
62 if (avio_rl32(pb))
63 st->codec->channels = 2;
64
65 st->codec->bits_per_coded_sample = 4;
66 st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels
67 * st->codec->sample_rate;
68 st->codec->block_align = 1;
69
70 return 0;
71 }
72
73 #define MAX_READ_SIZE 4096
74
75 static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
76 {
77 if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
78 return AVERROR(EIO);
79 pkt->stream_index = 0;
80 return 0;
81 }
82
83 AVInputFormat ff_apc_demuxer = {
84 .name = "apc",
85 .long_name = NULL_IF_CONFIG_SMALL("CRYO APC format"),
86 .read_probe = apc_probe,
87 .read_header = apc_read_header,
88 .read_packet = apc_read_packet,
89 };