lavf: make avio_read_partial() public
[libav.git] / libavformat / g729dec.c
1 /*
2 * G.729 raw format demuxer
3 * Copyright (c) 2011 Vladimir Voroshilov
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 "libavutil/log.h"
23 #include "libavutil/opt.h"
24
25 #include "avformat.h"
26 #include "internal.h"
27
28 typedef struct G729DemuxerContext {
29 AVClass *class;
30
31 int bit_rate;
32 } G729DemuxerContext;
33
34 static int g729_read_header(AVFormatContext *s)
35 {
36 AVStream* st;
37 G729DemuxerContext *s1 = s->priv_data;
38
39 st = avformat_new_stream(s, NULL);
40 if (!st)
41 return AVERROR(ENOMEM);
42
43 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
44 st->codecpar->codec_id = AV_CODEC_ID_G729;
45 st->codecpar->sample_rate = 8000;
46 st->codecpar->channels = 1;
47
48 if (s1 && s1->bit_rate)
49 s->bit_rate = s1->bit_rate;
50
51 switch(s->bit_rate) {
52 case 6400:
53 st->codecpar->block_align = 8;
54 break;
55 case 8000:
56 st->codecpar->block_align = 10;
57 break;
58 default:
59 av_log(s, AV_LOG_ERROR, "Invalid bit_rate value %d. "
60 "Only 6400 and 8000 b/s are supported.", s->bit_rate);
61 return AVERROR(EINVAL);
62 }
63
64 avpriv_set_pts_info(st, st->codecpar->block_align << 3, 1,
65 st->codecpar->sample_rate);
66
67 return 0;
68 }
69
70 static int g729_read_packet(AVFormatContext *s, AVPacket *pkt)
71 {
72 AVStream *st = s->streams[0];
73 int ret = av_get_packet(s->pb, pkt, st->codecpar->block_align);
74 if (ret < 0)
75 return ret;
76
77 pkt->stream_index = 0;
78 pkt->dts = pkt->pts = pkt->pos / st->codecpar->block_align;
79
80 return 0;
81 }
82
83 #define OFFSET(x) offsetof(G729DemuxerContext, x)
84 static const AVOption g729_options[] = {
85 { "bit_rate", "", OFFSET(bit_rate), AV_OPT_TYPE_INT, { .i64 = 8000 }, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
86 { NULL },
87 };
88
89 static const AVClass g729_demuxer_class = {
90 .class_name = "g729 demuxer",
91 .item_name = av_default_item_name,
92 .option = g729_options,
93 .version = LIBAVUTIL_VERSION_INT,
94 };
95
96 AVInputFormat ff_g729_demuxer = {
97 .name = "g729",
98 .long_name = NULL_IF_CONFIG_SMALL("G.729 raw format demuxer"),
99 .priv_data_size = sizeof(G729DemuxerContext),
100 .read_header = g729_read_header,
101 .read_packet = g729_read_packet,
102 .flags = AVFMT_GENERIC_INDEX,
103 .extensions = "g729",
104 .priv_class = &g729_demuxer_class,
105 };