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g723_1.c
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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"
29 #include "avformat.h"
30 #include "internal.h"
31 
32 static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
33 
35 {
36  AVStream *st;
37 
38  st = avformat_new_stream(s, NULL);
39  if (!st)
40  return AVERROR(ENOMEM);
41 
45  st->codec->channels = 1;
46  st->codec->sample_rate = 8000;
47 
48  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
49  st->start_time = 0;
50 
51  return 0;
52 }
53 
55 {
56  int size, byte, ret;
57 
58  pkt->pos = avio_tell(s->pb);
59  byte = avio_r8(s->pb);
60  size = frame_size[byte & 3];
61 
62  ret = av_new_packet(pkt, size);
63  if (ret < 0)
64  return ret;
65 
66  pkt->data[0] = byte;
67  pkt->duration = 240;
68  pkt->stream_index = 0;
69 
70  ret = avio_read(s->pb, pkt->data + 1, size - 1);
71  if (ret < size - 1) {
72  av_free_packet(pkt);
73  return ret < 0 ? ret : AVERROR_EOF;
74  }
75 
76  return pkt->size;
77 }
78 
80  .name = "g723_1",
81  .long_name = NULL_IF_CONFIG_SMALL("G.723.1"),
82  .read_header = g723_1_init,
83  .read_packet = g723_1_read_packet,
84  .extensions = "tco,rco,g723_1",
85  .flags = AVFMT_GENERIC_INDEX
86 };