xref: /third_party/ffmpeg/libavformat/g723_1.c (revision cabdff1a)
1/*
2 * G.723.1 demuxer
3 * Copyright (c) 2010 Mohamed Naufal Basheer
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/**
23 * @file
24 * G.723.1 demuxer
25 */
26
27#include "libavutil/attributes.h"
28#include "libavutil/channel_layout.h"
29#include "avformat.h"
30#include "internal.h"
31
32static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
33
34static av_cold int g723_1_init(AVFormatContext *s)
35{
36    AVStream *st;
37
38    st = avformat_new_stream(s, NULL);
39    if (!st)
40        return AVERROR(ENOMEM);
41
42    st->codecpar->codec_type     = AVMEDIA_TYPE_AUDIO;
43    st->codecpar->codec_id       = AV_CODEC_ID_G723_1;
44    st->codecpar->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
45    st->codecpar->sample_rate    = 8000;
46
47    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
48    st->start_time = 0;
49
50    return 0;
51}
52
53static 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        return ret < 0 ? ret : AVERROR_EOF;
72    }
73
74    return pkt->size;
75}
76
77const AVInputFormat ff_g723_1_demuxer = {
78    .name        = "g723_1",
79    .long_name   = NULL_IF_CONFIG_SMALL("G.723.1"),
80    .read_header = g723_1_init,
81    .read_packet = g723_1_read_packet,
82    .extensions  = "tco,rco,g723_1",
83    .flags       = AVFMT_GENERIC_INDEX
84};
85