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
|
/*
* Copyrightm (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "AudioCodec.h"
#include "gsmamr_dec.h"
#include "gsmamr_enc.h"
namespace {
class GsmEfrCodec : public AudioCodec
{
public:
GsmEfrCodec() {
if (AMREncodeInit(&mEncoder, &mSidSync, false)) {
mEncoder = NULL;
}
if (GSMInitDecode(&mDecoder, (Word8 *)"RTP")) {
mDecoder = NULL;
}
}
~GsmEfrCodec() {
if (mEncoder) {
AMREncodeExit(&mEncoder, &mSidSync);
}
if (mDecoder) {
GSMDecodeFrameExit(&mDecoder);
}
}
int set(int sampleRate, const char *fmtp) {
return (sampleRate == 8000 && mEncoder && mDecoder) ? 160 : -1;
}
int encode(void *payload, int16_t *samples);
int decode(int16_t *samples, void *payload, int length);
private:
void *mEncoder;
void *mSidSync;
void *mDecoder;
};
int GsmEfrCodec::encode(void *payload, int16_t *samples)
{
unsigned char *bytes = (unsigned char *)payload;
Frame_Type_3GPP type;
int length = AMREncode(mEncoder, mSidSync, MR122,
samples, bytes, &type, AMR_TX_WMF);
if (type == AMR_122 && length == 32) {
bytes[0] = 0xC0 | (bytes[1] >> 4);
for (int i = 1; i < 31; ++i) {
bytes[i] = (bytes[i] << 4) | (bytes[i + 1] >> 4);
}
return 31;
}
return -1;
}
int GsmEfrCodec::decode(int16_t *samples, void *payload, int length)
{
unsigned char *bytes = (unsigned char *)payload;
if (length == 31 && (bytes[0] >> 4) == 0x0C) {
for (int i = 0; i < 30; ++i) {
bytes[i] = (bytes[i] << 4) | (bytes[i + 1] >> 4);
}
bytes[30] <<= 4;
if (AMRDecode(mDecoder, AMR_122, bytes, samples, MIME_IETF) == 31) {
return 160;
}
}
return -1;
}
} // namespace
AudioCodec *newGsmEfrCodec()
{
return new GsmEfrCodec;
}
|
