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/*
* 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()
: sample_rate_hz(8000),
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 (sample_rate_hz != 8000 && sample_rate_hz != 16000)
return false;
if (num_channels != 1)
return false;
if (!speech_encoder)
return false;
if (num_channels != speech_encoder->num_channels())
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),
sample_rate_hz_(config.sample_rate_hz),
num_channels_(config.num_channels),
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(), sample_rate_hz_,
config.sid_frame_interval_ms,
config.num_cng_coefficients),
0)
<< "WebRtcCng_InitEnc failed";
}
AudioEncoderCng::~AudioEncoderCng() {
}
int AudioEncoderCng::sample_rate_hz() const {
return sample_rate_hz_;
}
int AudioEncoderCng::num_channels() const {
return num_channels_;
}
int AudioEncoderCng::Num10MsFramesInNextPacket() const {
return speech_encoder_->Num10MsFramesInNextPacket();
}
int AudioEncoderCng::Max10MsFramesInAPacket() const {
return speech_encoder_->Max10MsFramesInAPacket();
}
bool AudioEncoderCng::EncodeInternal(uint32_t timestamp,
const int16_t* audio,
size_t max_encoded_bytes,
uint8_t* encoded,
EncodedInfo* info) {
DCHECK_GE(max_encoded_bytes, static_cast<size_t>(num_cng_coefficients_ + 1));
if (max_encoded_bytes < static_cast<size_t>(num_cng_coefficients_ + 1)) {
return false;
}
info->encoded_bytes = 0;
const int num_samples = sample_rate_hz() / 100 * num_channels();
if (speech_buffer_.empty()) {
CHECK_EQ(frames_in_buffer_, 0);
first_timestamp_in_buffer_ = 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 true;
}
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 * sample_rate_hz_ / 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,
sample_rate_hz_);
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, sample_rate_hz_);
}
DCHECK_NE(activity, Vad::kError);
bool return_val = true;
switch (activity) {
case Vad::kPassive: {
return_val = EncodePassive(encoded, &info->encoded_bytes);
info->encoded_timestamp = first_timestamp_in_buffer_;
info->payload_type = cng_payload_type_;
last_frame_active_ = false;
break;
}
case Vad::kActive: {
return_val = EncodeActive(max_encoded_bytes, encoded, info);
last_frame_active_ = true;
break;
}
case Vad::kError: {
return_val = false;
break;
}
}
speech_buffer_.clear();
frames_in_buffer_ = 0;
return return_val;
}
bool 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 * sample_rate_hz_ / 1000;
for (int i = 0; i < frames_in_buffer_; ++i) {
int16_t encoded_bytes_tmp = 0;
if (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)
return false;
if (encoded_bytes_tmp > 0) {
CHECK(!output_produced);
*encoded_bytes = static_cast<size_t>(encoded_bytes_tmp);
output_produced = true;
force_sid = false;
}
CHECK(!force_sid) << "SID frame not produced despite being forced.";
}
return true;
}
bool AudioEncoderCng::EncodeActive(size_t max_encoded_bytes,
uint8_t* encoded,
EncodedInfo* info) {
const size_t samples_per_10ms_frame = 10 * sample_rate_hz_ / 1000;
for (int i = 0; i < frames_in_buffer_; ++i) {
if (!speech_encoder_->Encode(first_timestamp_in_buffer_,
&speech_buffer_[i * samples_per_10ms_frame],
samples_per_10ms_frame, max_encoded_bytes,
encoded, info))
return false;
if (i < frames_in_buffer_ - 1) {
CHECK_EQ(info->encoded_bytes, 0u) << "Encoder delivered data too early.";
}
}
return true;
}
} // namespace webrtc
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