G.723.1 demuxer and decoder
[libav.git] / libavformat / g723_1.c
1 /*
2 * G.723.1 demuxer
3 * Copyright (c) 2010 Mohamed Naufal Basheer
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 /**
23 * @file
24 * G.723.1 demuxer
25 */
26
27 #include "libavutil/audioconvert.h"
28 #include "avformat.h"
29 #include "internal.h"
30
31 static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
32
33 static int g723_1_init(AVFormatContext *s)
34 {
35 AVStream *st;
36
37 st = avformat_new_stream(s, NULL);
38 if (!st)
39 return AVERROR(ENOMEM);
40
41 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
42 st->codec->codec_id = CODEC_ID_G723_1;
43 st->codec->channel_layout = AV_CH_LAYOUT_MONO;
44 st->codec->channels = 1;
45 st->codec->sample_rate = 8000;
46
47 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
48 st->start_time = 0;
49
50 return 0;
51 }
52
53 static int g723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
54 {
55 int size, byte, ret;
56
57 pkt->pos = avio_tell(s->pb);
58 byte = avio_r8(s->pb);
59 size = frame_size[byte & 3];
60
61 ret = av_new_packet(pkt, size);
62 if (ret < 0)
63 return ret;
64
65 pkt->data[0] = byte;
66 pkt->duration = 240;
67 pkt->stream_index = 0;
68
69 ret = avio_read(s->pb, pkt->data + 1, size - 1);
70 if (ret < size - 1) {
71 av_free_packet(pkt);
72 return ret < 0 ? ret : AVERROR_EOF;
73 }
74
75 return pkt->size;
76 }
77
78 AVInputFormat ff_g723_1_demuxer = {
79 .name = "g723_1",
80 .long_name = NULL_IF_CONFIG_SMALL("G.723.1 format"),
81 .read_header = g723_1_init,
82 .read_packet = g723_1_read_packet,
83 .extensions = "tco",
84 .flags = AVFMT_GENERIC_INDEX
85 };