blob: b180a50c9bd01e20476b2a12bd7e39793baede8d
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 <string.h> |
23 | |
24 | #include "libavutil/channel_layout.h" |
25 | #include "avformat.h" |
26 | #include "internal.h" |
27 | |
28 | static int apc_probe(AVProbeData *p) |
29 | { |
30 | if (!strncmp(p->buf, "CRYO_APC", 8)) |
31 | return AVPROBE_SCORE_MAX; |
32 | |
33 | return 0; |
34 | } |
35 | |
36 | static int apc_read_header(AVFormatContext *s) |
37 | { |
38 | AVIOContext *pb = s->pb; |
39 | AVStream *st; |
40 | |
41 | avio_rl32(pb); /* CRYO */ |
42 | avio_rl32(pb); /* _APC */ |
43 | avio_rl32(pb); /* 1.20 */ |
44 | |
45 | st = avformat_new_stream(s, NULL); |
46 | if (!st) |
47 | return AVERROR(ENOMEM); |
48 | |
49 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
50 | st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_APC; |
51 | |
52 | avio_rl32(pb); /* number of samples */ |
53 | st->codecpar->sample_rate = avio_rl32(pb); |
54 | |
55 | /* initial predictor values for adpcm decoder */ |
56 | if (ff_get_extradata(s, st->codecpar, pb, 2 * 4) < 0) |
57 | return AVERROR(ENOMEM); |
58 | |
59 | if (avio_rl32(pb)) { |
60 | st->codecpar->channels = 2; |
61 | st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO; |
62 | } else { |
63 | st->codecpar->channels = 1; |
64 | st->codecpar->channel_layout = AV_CH_LAYOUT_MONO; |
65 | } |
66 | |
67 | st->codecpar->bits_per_coded_sample = 4; |
68 | st->codecpar->bit_rate = (int64_t)st->codecpar->bits_per_coded_sample * st->codecpar->channels |
69 | * st->codecpar->sample_rate; |
70 | st->codecpar->block_align = 1; |
71 | |
72 | return 0; |
73 | } |
74 | |
75 | #define MAX_READ_SIZE 4096 |
76 | |
77 | static int apc_read_packet(AVFormatContext *s, AVPacket *pkt) |
78 | { |
79 | if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0) |
80 | return AVERROR(EIO); |
81 | pkt->flags &= ~AV_PKT_FLAG_CORRUPT; |
82 | pkt->stream_index = 0; |
83 | return 0; |
84 | } |
85 | |
86 | AVInputFormat ff_apc_demuxer = { |
87 | .name = "apc", |
88 | .long_name = NULL_IF_CONFIG_SMALL("CRYO APC"), |
89 | .read_probe = apc_probe, |
90 | .read_header = apc_read_header, |
91 | .read_packet = apc_read_packet, |
92 | }; |
93 |