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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2014, Digium, Inc.
*
* Joshua Colp <jcolp@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
*
* \brief Media Format Bitfield Compatibility API
*
* \author Joshua Colp <jcolp@digium.com>
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/logger.h"
#include "asterisk/astobj2.h"
#include "asterisk/codec.h"
#include "asterisk/format.h"
#include "asterisk/format_compatibility.h"
#include "asterisk/format_cache.h"
#include "asterisk/format_cap.h"
#include "asterisk/utils.h"
#include "include/format_compatibility.h"
uint64_t iax2_format_compatibility_cap2bitfield(const struct ast_format_cap *cap)
{
uint64_t bitfield = 0;
int x;
for (x = 0; x < ast_format_cap_count(cap); x++) {
struct ast_format *format = ast_format_cap_get_format(cap, x);
bitfield |= ast_format_compatibility_format2bitfield(format);
ao2_ref(format, -1);
}
return bitfield;
}
int iax2_format_compatibility_bitfield2cap(uint64_t bitfield, struct ast_format_cap *cap)
{
int bit;
for (bit = 0; bit < 64; ++bit) {
uint64_t mask = (1ULL << bit);
if (mask & bitfield) {
struct ast_format *format;
format = ast_format_compatibility_bitfield2format(mask);
if (format && ast_format_cap_append(cap, format, 0)) {
return -1;
}
}
}
return 0;
}
uint64_t iax2_format_compatibility_best(uint64_t formats)
{
/*
* This just our opinion, expressed in code. We are
* asked to choose the best codec to use, given no
* information.
*/
static const uint64_t best[] = {
/*! Okay, ulaw is used by all telephony equipment, so start with it */
AST_FORMAT_ULAW,
/*! Unless of course, you're a silly European, so then prefer ALAW */
AST_FORMAT_ALAW,
AST_FORMAT_G719,
AST_FORMAT_SIREN14,
AST_FORMAT_SIREN7,
AST_FORMAT_TESTLAW,
/*! G.722 is better then all below, but not as common as the above... so give ulaw and alaw priority */
AST_FORMAT_G722,
/*! Okay, well, signed linear is easy to translate into other stuff */
AST_FORMAT_SLIN16,
AST_FORMAT_SLIN,
/*! G.726 is standard ADPCM, in RFC3551 packing order */
AST_FORMAT_G726,
/*! G.726 is standard ADPCM, in AAL2 packing order */
AST_FORMAT_G726_AAL2,
/*! ADPCM has great sound quality and is still pretty easy to translate */
AST_FORMAT_ADPCM,
/*! Okay, we're down to vocoders now, so pick GSM because it's small and easier to
translate and sounds pretty good */
AST_FORMAT_GSM,
/*! iLBC is not too bad */
AST_FORMAT_ILBC,
/*! Speex is free, but computationally more expensive than GSM */
AST_FORMAT_SPEEX16,
AST_FORMAT_SPEEX,
/*! Opus */
AST_FORMAT_OPUS,
/*! Ick, LPC10 sounds terrible, but at least we have code for it, if you're tacky enough
to use it */
AST_FORMAT_LPC10,
/*! G.729a is faster than 723 and slightly less expensive */
AST_FORMAT_G729,
/*! Down to G.723.1 which is proprietary but at least designed for voice */
AST_FORMAT_G723,
};
int idx;
/* Find the first preferred codec in the format given */
for (idx = 0; idx < ARRAY_LEN(best); ++idx) {
if (formats & best[idx]) {
return best[idx];
}
}
return 0;
}
|
