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
|
/* G726decode.c
* G.726 codec
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later*/
#include "config.h"
#include <glib.h>
#ifdef HAVE_SPANDSP
#include "spandsp.h"
#include "G726decode.h"
#include "ws_attributes.h"
typedef struct _g726_codec_ctx {
g726_state_t *state;
int bit_rate;
} g726_codec_ctx;
static inline void *
codec_g726_init(int bit_rate, int packing)
{
g726_state_t *decoder = g726_init(NULL, bit_rate, G726_ENCODING_LINEAR, packing);
if (!decoder) {
return NULL; /* out-of-memory; */
}
g726_codec_ctx *state = g_new(g726_codec_ctx, 1);
state->state = decoder;
state->bit_rate = bit_rate;
return state;
}
void *codec_g726_16_init(void) { return codec_g726_init(16000, G726_PACKING_RIGHT); }
void *codec_g726_24_init(void) { return codec_g726_init(24000, G726_PACKING_RIGHT); }
void *codec_g726_32_init(void) { return codec_g726_init(32000, G726_PACKING_RIGHT); }
void *codec_g726_40_init(void) { return codec_g726_init(40000, G726_PACKING_RIGHT); }
void *codec_aal2_g726_16_init(void) { return codec_g726_init(16000, G726_PACKING_LEFT); }
void *codec_aal2_g726_24_init(void) { return codec_g726_init(24000, G726_PACKING_LEFT); }
void *codec_aal2_g726_32_init(void) { return codec_g726_init(32000, G726_PACKING_LEFT); }
void *codec_aal2_g726_40_init(void) { return codec_g726_init(40000, G726_PACKING_LEFT); }
void
codec_g726_release(void *ctx)
{
g726_codec_ctx *state = (g726_codec_ctx *)ctx;
if (!state) {
return; /* out-of-memory; */
}
/* Note: replaces g726_release since SpanDSP 20090211 */
g726_free(state->state);
g_free(state);
}
unsigned
codec_g726_get_channels(void *ctx _U_)
{
return 1;
}
unsigned
codec_g726_get_frequency(void *ctx _U_)
{
return 8000;
}
size_t
codec_g726_decode(void *ctx, const void *input, size_t inputSizeBytes, void *output,
size_t *outputSizeBytes)
{
g726_codec_ctx *state = (g726_codec_ctx *)ctx;
if (!state) {
return 0; /* out-of-memory; */
}
if (!output || !outputSizeBytes) {
/*
* sample rate 8kHz, for bitrate 16kHz we have 16/8 = 2 bits/sample, so
* 1 input byte (8 bits) will expand to four 16-bit samples. Likewise,
* for bitrate 40kHz we have 40/8 = 5 bits/sample. Alternatively:
* bitsPerSample = bitRate / sampleRate (8kHz).
* outputBytes = (inputBits / bitsPerSample) * sizeof(sample)
*/
return inputSizeBytes * 8 / (state->bit_rate / 8000) * 2;
}
/* g726_decode returns the number of 16-bit samples. */
*outputSizeBytes = 2 * g726_decode(state->state, (int16_t *)output, (const uint8_t *) input, (int)inputSizeBytes);
return *outputSizeBytes;
}
#endif
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
|
