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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/*
* Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webrtc/modules/audio_coding/codecs/cng/include/audio_encoder_cng.h"
#include <limits>
namespace webrtc {
AudioEncoderCng::Config::Config()
: num_channels(1),
payload_type(13),
speech_encoder(NULL),
vad_mode(Vad::kVadNormal),
sid_frame_interval_ms(100),
num_cng_coefficients(8),
vad(NULL) {
}
bool AudioEncoderCng::Config::IsOk() const {
if (num_channels != 1)
return false;
if (!speech_encoder)
return false;
if (num_channels != speech_encoder->NumChannels())
return false;
if (sid_frame_interval_ms < speech_encoder->Max10MsFramesInAPacket() * 10)
return false;
if (num_cng_coefficients > WEBRTC_CNG_MAX_LPC_ORDER ||
num_cng_coefficients <= 0)
return false;
return true;
}
AudioEncoderCng::AudioEncoderCng(const Config& config)
: speech_encoder_(config.speech_encoder),
cng_payload_type_(config.payload_type),
num_cng_coefficients_(config.num_cng_coefficients),
first_timestamp_in_buffer_(0),
frames_in_buffer_(0),
last_frame_active_(true),
vad_(new Vad(config.vad_mode)) {
if (config.vad) {
// Replace default Vad object with user-provided one.
vad_.reset(config.vad);
}
CHECK(config.IsOk()) << "Invalid configuration.";
CNG_enc_inst* cng_inst;
CHECK_EQ(WebRtcCng_CreateEnc(&cng_inst), 0) << "WebRtcCng_CreateEnc failed.";
cng_inst_.reset(cng_inst); // Transfer ownership to scoped_ptr.
CHECK_EQ(WebRtcCng_InitEnc(cng_inst_.get(), SampleRateHz(),
config.sid_frame_interval_ms,
config.num_cng_coefficients),
0)
<< "WebRtcCng_InitEnc failed";
}
AudioEncoderCng::~AudioEncoderCng() {
}
int AudioEncoderCng::SampleRateHz() const {
return speech_encoder_->SampleRateHz();
}
int AudioEncoderCng::RtpTimestampRateHz() const {
return speech_encoder_->RtpTimestampRateHz();
}
int AudioEncoderCng::NumChannels() const {
return 1;
}
int AudioEncoderCng::Num10MsFramesInNextPacket() const {
return speech_encoder_->Num10MsFramesInNextPacket();
}
int AudioEncoderCng::Max10MsFramesInAPacket() const {
return speech_encoder_->Max10MsFramesInAPacket();
}
void AudioEncoderCng::SetTargetBitrate(int bits_per_second) {
speech_encoder_->SetTargetBitrate(bits_per_second);
}
void AudioEncoderCng::SetProjectedPacketLossRate(double fraction) {
DCHECK_GE(fraction, 0.0);
DCHECK_LE(fraction, 1.0);
speech_encoder_->SetProjectedPacketLossRate(fraction);
}
void AudioEncoderCng::EncodeInternal(uint32_t rtp_timestamp,
const int16_t* audio,
size_t max_encoded_bytes,
uint8_t* encoded,
EncodedInfo* info) {
CHECK_GE(max_encoded_bytes, static_cast<size_t>(num_cng_coefficients_ + 1));
info->encoded_bytes = 0;
const int num_samples = SampleRateHz() / 100 * NumChannels();
if (speech_buffer_.empty()) {
CHECK_EQ(frames_in_buffer_, 0);
first_timestamp_in_buffer_ = rtp_timestamp;
}
for (int i = 0; i < num_samples; ++i) {
speech_buffer_.push_back(audio[i]);
}
++frames_in_buffer_;
if (frames_in_buffer_ < speech_encoder_->Num10MsFramesInNextPacket()) {
return;
}
CHECK_LE(frames_in_buffer_, 6)
<< "Frame size cannot be larger than 60 ms when using VAD/CNG.";
const size_t samples_per_10ms_frame = 10 * SampleRateHz() / 1000;
CHECK_EQ(speech_buffer_.size(),
static_cast<size_t>(frames_in_buffer_) * samples_per_10ms_frame);
// Group several 10 ms blocks per VAD call. Call VAD once or twice using the
// following split sizes:
// 10 ms = 10 + 0 ms; 20 ms = 20 + 0 ms; 30 ms = 30 + 0 ms;
// 40 ms = 20 + 20 ms; 50 ms = 30 + 20 ms; 60 ms = 30 + 30 ms.
int blocks_in_first_vad_call =
(frames_in_buffer_ > 3 ? 3 : frames_in_buffer_);
if (frames_in_buffer_ == 4)
blocks_in_first_vad_call = 2;
const int blocks_in_second_vad_call =
frames_in_buffer_ - blocks_in_first_vad_call;
CHECK_GE(blocks_in_second_vad_call, 0);
// Check if all of the buffer is passive speech. Start with checking the first
// block.
Vad::Activity activity = vad_->VoiceActivity(
&speech_buffer_[0], samples_per_10ms_frame * blocks_in_first_vad_call,
SampleRateHz());
if (activity == Vad::kPassive && blocks_in_second_vad_call > 0) {
// Only check the second block if the first was passive.
activity = vad_->VoiceActivity(
&speech_buffer_[samples_per_10ms_frame * blocks_in_first_vad_call],
samples_per_10ms_frame * blocks_in_second_vad_call, SampleRateHz());
}
switch (activity) {
case Vad::kPassive: {
EncodePassive(encoded, &info->encoded_bytes);
info->encoded_timestamp = first_timestamp_in_buffer_;
info->payload_type = cng_payload_type_;
info->send_even_if_empty = true;
info->speech = false;
last_frame_active_ = false;
break;
}
case Vad::kActive: {
EncodeActive(max_encoded_bytes, encoded, info);
last_frame_active_ = true;
break;
}
case Vad::kError: {
FATAL(); // Fails only if fed invalid data.
break;
}
}
speech_buffer_.clear();
frames_in_buffer_ = 0;
}
void AudioEncoderCng::EncodePassive(uint8_t* encoded, size_t* encoded_bytes) {
bool force_sid = last_frame_active_;
bool output_produced = false;
const size_t samples_per_10ms_frame = 10 * SampleRateHz() / 1000;
for (int i = 0; i < frames_in_buffer_; ++i) {
int16_t encoded_bytes_tmp = 0;
CHECK_GE(WebRtcCng_Encode(cng_inst_.get(),
&speech_buffer_[i * samples_per_10ms_frame],
static_cast<int16_t>(samples_per_10ms_frame),
encoded, &encoded_bytes_tmp, force_sid), 0);
if (encoded_bytes_tmp > 0) {
CHECK(!output_produced);
*encoded_bytes = static_cast<size_t>(encoded_bytes_tmp);
output_produced = true;
force_sid = false;
}
}
}
void AudioEncoderCng::EncodeActive(size_t max_encoded_bytes,
uint8_t* encoded,
EncodedInfo* info) {
const size_t samples_per_10ms_frame = 10 * SampleRateHz() / 1000;
for (int i = 0; i < frames_in_buffer_; ++i) {
speech_encoder_->Encode(first_timestamp_in_buffer_,
&speech_buffer_[i * samples_per_10ms_frame],
samples_per_10ms_frame, max_encoded_bytes,
encoded, info);
if (i < frames_in_buffer_ - 1) {
CHECK_EQ(info->encoded_bytes, 0u) << "Encoder delivered data too early.";
}
}
}
} // namespace webrtc
|
