1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
/* AMR RTP Payload according to RFC4867. Only one codec frame per RTP */
/* (C) 2017 by Harald Welte <laforge@gnumonks.org> */
/*
* This file is part of gapk (GSM Audio Pocket Knife).
*
* gapk is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* gapk is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with gapk. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include <string.h>
#include <osmocom/codec/codec.h>
#include <osmocom/gapk/codecs.h>
#include <osmocom/gapk/formats.h>
#include <osmocom/gapk/utils.h>
/* conversion function: RTP payload -> canonical format */
static int
rtp_amr_from_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len)
{
/* add Payload Header according to RFC4867 4.4.1 */
dst[0] = 0xf0; /* no request */
memcpy(dst+1, src, src_len);
return src_len+1;
}
/* conversion function: canonical format -> RTP payload */
static int
rtp_amr_to_canon(uint8_t *dst, const uint8_t *src, unsigned int src_len)
{
/* skip Payload Header according to RFC4867 4.4.1 */
memcpy(dst, src+1, src_len-1);
return src_len-1;
}
const struct osmo_gapk_format_desc fmt_rtp_amr = {
.type = FMT_RTP_AMR,
.codec_type = CODEC_AMR,
.name = "rtp-amr",
.description = "RTP payload for AMR according to RFC4867",
.frame_len = 0,
.conv_from_canon = rtp_amr_from_canon,
.conv_to_canon = rtp_amr_to_canon,
};
|
