modules/audio_processing/aec3/echo_remover.cc - src/webrtc - Git at Google

 /*
  *  Copyright (c) 2017 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_processing/aec3/echo_remover.h"

 #include <math.h>
 #include <algorithm>
 #include <memory>
 #include <numeric>
 #include <string>

 #include "webrtc/api/array_view.h"
 #include "webrtc/modules/audio_processing/aec3/aec3_common.h"
 #include "webrtc/modules/audio_processing/aec3/aec_state.h"
 #include "webrtc/modules/audio_processing/aec3/comfort_noise_generator.h"
 #include "webrtc/modules/audio_processing/aec3/echo_path_variability.h"
 #include "webrtc/modules/audio_processing/aec3/echo_remover_metrics.h"
 #include "webrtc/modules/audio_processing/aec3/fft_data.h"
 #include "webrtc/modules/audio_processing/aec3/output_selector.h"
 #include "webrtc/modules/audio_processing/aec3/render_buffer.h"
 #include "webrtc/modules/audio_processing/aec3/render_delay_buffer.h"
 #include "webrtc/modules/audio_processing/aec3/residual_echo_estimator.h"
 #include "webrtc/modules/audio_processing/aec3/subtractor.h"
 #include "webrtc/modules/audio_processing/aec3/suppression_filter.h"
 #include "webrtc/modules/audio_processing/aec3/suppression_gain.h"
 #include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
 #include "webrtc/rtc_base/atomicops.h"
 #include "webrtc/rtc_base/constructormagic.h"

 namespace webrtc {

 namespace {

 void LinearEchoPower(const FftData& E,
                      const FftData& Y,
                      std::array<float, kFftLengthBy2Plus1>* S2) {
   for (size_t k = 0; k < E.re.size(); ++k) {
     (*S2)[k] = (Y.re[k] - E.re[k]) * (Y.re[k] - E.re[k]) +
                (Y.im[k] - E.im[k]) * (Y.im[k] - E.im[k]);
   }
 }

 // Class for removing the echo from the capture signal.
 class EchoRemoverImpl final : public EchoRemover {
  public:
   explicit EchoRemoverImpl(
       const AudioProcessing::Config::EchoCanceller3& config,
       int sample_rate_hz);
   ~EchoRemoverImpl() override;

   // Removes the echo from a block of samples from the capture signal. The
   // supplied render signal is assumed to be pre-aligned with the capture
   // signal.
   void ProcessCapture(const rtc::Optional<size_t>& echo_path_delay_samples,
                       const EchoPathVariability& echo_path_variability,
                       bool capture_signal_saturation,
                       const RenderBuffer& render_buffer,
                       std::vector<std::vector<float>>* capture) override;

   // Updates the status on whether echo leakage is detected in the output of the
   // echo remover.
   void UpdateEchoLeakageStatus(bool leakage_detected) override {
     echo_leakage_detected_ = leakage_detected;
   }

  private:
   static int instance_count_;
   const AudioProcessing::Config::EchoCanceller3 config_;
   const Aec3Fft fft_;
   std::unique_ptr<ApmDataDumper> data_dumper_;
   const Aec3Optimization optimization_;
   const int sample_rate_hz_;
   Subtractor subtractor_;
   SuppressionGain suppression_gain_;
   ComfortNoiseGenerator cng_;
   SuppressionFilter suppression_filter_;
   RenderSignalAnalyzer render_signal_analyzer_;
   OutputSelector output_selector_;
   ResidualEchoEstimator residual_echo_estimator_;
   bool echo_leakage_detected_ = false;
   AecState aec_state_;
   EchoRemoverMetrics metrics_;

   RTC_DISALLOW_COPY_AND_ASSIGN(EchoRemoverImpl);
 };

 int EchoRemoverImpl::instance_count_ = 0;

 EchoRemoverImpl::EchoRemoverImpl(
     const AudioProcessing::Config::EchoCanceller3& config,
     int sample_rate_hz)
     : config_(config),
       fft_(),
       data_dumper_(
           new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
       optimization_(DetectOptimization()),
       sample_rate_hz_(sample_rate_hz),
       subtractor_(data_dumper_.get(), optimization_),
       suppression_gain_(config_, optimization_),
       cng_(optimization_),
       suppression_filter_(sample_rate_hz_),
       residual_echo_estimator_(config_),
       aec_state_(config_) {
   RTC_DCHECK(ValidFullBandRate(sample_rate_hz));
 }

 EchoRemoverImpl::~EchoRemoverImpl() = default;

 void EchoRemoverImpl::ProcessCapture(
     const rtc::Optional<size_t>& echo_path_delay_samples,
     const EchoPathVariability& echo_path_variability,
     bool capture_signal_saturation,
     const RenderBuffer& render_buffer,
     std::vector<std::vector<float>>* capture) {
   const std::vector<std::vector<float>>& x = render_buffer.MostRecentBlock();
   std::vector<std::vector<float>>* y = capture;

   RTC_DCHECK(y);
   RTC_DCHECK_EQ(x.size(), NumBandsForRate(sample_rate_hz_));
   RTC_DCHECK_EQ(y->size(), NumBandsForRate(sample_rate_hz_));
   RTC_DCHECK_EQ(x[0].size(), kBlockSize);
   RTC_DCHECK_EQ((*y)[0].size(), kBlockSize);
   const std::vector<float>& x0 = x[0];
   std::vector<float>& y0 = (*y)[0];

   data_dumper_->DumpWav("aec3_echo_remover_capture_input", kBlockSize, &y0[0],
                         LowestBandRate(sample_rate_hz_), 1);
   data_dumper_->DumpWav("aec3_echo_remover_render_input", kBlockSize, &x0[0],
                         LowestBandRate(sample_rate_hz_), 1);
   data_dumper_->DumpRaw("aec3_echo_remover_capture_input", y0);
   data_dumper_->DumpRaw("aec3_echo_remover_render_input", x0);

   aec_state_.UpdateCaptureSaturation(capture_signal_saturation);

   if (echo_path_variability.AudioPathChanged()) {
     subtractor_.HandleEchoPathChange(echo_path_variability);
     aec_state_.HandleEchoPathChange(echo_path_variability);
   }

   std::array<float, kFftLengthBy2Plus1> Y2;
   std::array<float, kFftLengthBy2Plus1> R2;
   std::array<float, kFftLengthBy2Plus1> S2_linear;
   std::array<float, kFftLengthBy2Plus1> G;
   float high_bands_gain;
   FftData Y;
   FftData comfort_noise;
   FftData high_band_comfort_noise;
   SubtractorOutput subtractor_output;
   FftData& E_main = subtractor_output.E_main;
   auto& E2_main = subtractor_output.E2_main;
   auto& E2_shadow = subtractor_output.E2_shadow;
   auto& e_main = subtractor_output.e_main;

   // Analyze the render signal.
   render_signal_analyzer_.Update(render_buffer, aec_state_.FilterDelay());

   // Perform linear echo cancellation.
   subtractor_.Process(render_buffer, y0, render_signal_analyzer_, aec_state_,
                       &subtractor_output);

   // Compute spectra.
   fft_.ZeroPaddedFft(y0, &Y);
   LinearEchoPower(E_main, Y, &S2_linear);
   Y.Spectrum(optimization_, &Y2);

   // Update the AEC state information.
   aec_state_.Update(subtractor_.FilterFrequencyResponse(),
                     subtractor_.FilterImpulseResponse(),
                     echo_path_delay_samples, render_buffer, E2_main, Y2, x0,
                     subtractor_output.s_main, echo_leakage_detected_);

   // Choose the linear output.
   output_selector_.FormLinearOutput(!aec_state_.HeadsetDetected(), e_main, y0);
   data_dumper_->DumpWav("aec3_output_linear", kBlockSize, &y0[0],
                         LowestBandRate(sample_rate_hz_), 1);
   data_dumper_->DumpRaw("aec3_output_linear", y0);
   const auto& E2 = output_selector_.UseSubtractorOutput() ? E2_main : Y2;

   // Estimate the residual echo power.
   residual_echo_estimator_.Estimate(output_selector_.UseSubtractorOutput(),
                                     aec_state_, render_buffer, S2_linear, Y2,
                                     &R2);

   // Estimate the comfort noise.
   cng_.Compute(aec_state_, Y2, &comfort_noise, &high_band_comfort_noise);

   // A choose and apply echo suppression gain.
   suppression_gain_.GetGain(E2, R2, cng_.NoiseSpectrum(),
                             render_signal_analyzer_, aec_state_.SaturatedEcho(),
                             x, aec_state_.ForcedZeroGain(), &high_bands_gain,
                             &G);
   suppression_filter_.ApplyGain(comfort_noise, high_band_comfort_noise, G,
                                 high_bands_gain, y);

   // Update the metrics.
   metrics_.Update(aec_state_, cng_.NoiseSpectrum(), G);

   // Update the aec state with the aec output characteristics.
   aec_state_.UpdateWithOutput(y0);

   // Debug outputs for the purpose of development and analysis.
   data_dumper_->DumpWav("aec3_echo_estimate", kBlockSize,
                         &subtractor_output.s_main[0],
                         LowestBandRate(sample_rate_hz_), 1);
   data_dumper_->DumpRaw("aec3_output", y0);
   data_dumper_->DumpRaw("aec3_narrow_render",
                         render_signal_analyzer_.NarrowPeakBand() ? 1 : 0);
   data_dumper_->DumpRaw("aec3_N2", cng_.NoiseSpectrum());
   data_dumper_->DumpRaw("aec3_suppressor_gain", G);
   data_dumper_->DumpWav("aec3_output",
                         rtc::ArrayView<const float>(&y0[0], kBlockSize),
                         LowestBandRate(sample_rate_hz_), 1);
   data_dumper_->DumpRaw("aec3_using_subtractor_output",
                         output_selector_.UseSubtractorOutput() ? 1 : 0);
   data_dumper_->DumpRaw("aec3_E2", E2);
   data_dumper_->DumpRaw("aec3_E2_main", E2_main);
   data_dumper_->DumpRaw("aec3_E2_shadow", E2_shadow);
   data_dumper_->DumpRaw("aec3_S2_linear", S2_linear);
   data_dumper_->DumpRaw("aec3_Y2", Y2);
   data_dumper_->DumpRaw("aec3_X2", render_buffer.Spectrum(0));
   data_dumper_->DumpRaw("aec3_R2", R2);
   data_dumper_->DumpRaw("aec3_erle", aec_state_.Erle());
   data_dumper_->DumpRaw("aec3_erl", aec_state_.Erl());
   data_dumper_->DumpRaw("aec3_active_render", aec_state_.ActiveRender());
   data_dumper_->DumpRaw("aec3_usable_linear_estimate",
                         aec_state_.UsableLinearEstimate());
   data_dumper_->DumpRaw(
       "aec3_filter_delay",
       aec_state_.FilterDelay() ? *aec_state_.FilterDelay() : -1);
   data_dumper_->DumpRaw(
       "aec3_external_delay",
       aec_state_.ExternalDelay() ? *aec_state_.ExternalDelay() : -1);
   data_dumper_->DumpRaw("aec3_capture_saturation",
                         aec_state_.SaturatedCapture() ? 1 : 0);
 }

 }  // namespace

 EchoRemover* EchoRemover::Create(
     const AudioProcessing::Config::EchoCanceller3& config,
     int sample_rate_hz) {
   return new EchoRemoverImpl(config, sample_rate_hz);
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2017 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_processing/aec3/echo_remover.h"

	#include <math.h>
	#include <algorithm>
	#include <memory>
	#include <numeric>
	#include <string>

	#include "webrtc/api/array_view.h"
	#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
	#include "webrtc/modules/audio_processing/aec3/aec_state.h"
	#include "webrtc/modules/audio_processing/aec3/comfort_noise_generator.h"
	#include "webrtc/modules/audio_processing/aec3/echo_path_variability.h"
	#include "webrtc/modules/audio_processing/aec3/echo_remover_metrics.h"
	#include "webrtc/modules/audio_processing/aec3/fft_data.h"
	#include "webrtc/modules/audio_processing/aec3/output_selector.h"
	#include "webrtc/modules/audio_processing/aec3/render_buffer.h"
	#include "webrtc/modules/audio_processing/aec3/render_delay_buffer.h"
	#include "webrtc/modules/audio_processing/aec3/residual_echo_estimator.h"
	#include "webrtc/modules/audio_processing/aec3/subtractor.h"
	#include "webrtc/modules/audio_processing/aec3/suppression_filter.h"
	#include "webrtc/modules/audio_processing/aec3/suppression_gain.h"
	#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
	#include "webrtc/rtc_base/atomicops.h"
	#include "webrtc/rtc_base/constructormagic.h"

	namespace webrtc {

	namespace {

	void LinearEchoPower(const FftData& E,
	const FftData& Y,
	std::array<float, kFftLengthBy2Plus1>* S2) {
	for (size_t k = 0; k < E.re.size(); ++k) {
	(S2)[k] = (Y.re[k] - E.re[k]) (Y.re[k] - E.re[k]) +
	(Y.im[k] - E.im[k]) * (Y.im[k] - E.im[k]);
	}
	}

	// Class for removing the echo from the capture signal.
	class EchoRemoverImpl final : public EchoRemover {
	public:
	explicit EchoRemoverImpl(
	const AudioProcessing::Config::EchoCanceller3& config,
	int sample_rate_hz);
	~EchoRemoverImpl() override;

	// Removes the echo from a block of samples from the capture signal. The
	// supplied render signal is assumed to be pre-aligned with the capture
	// signal.
	void ProcessCapture(const rtc::Optional<size_t>& echo_path_delay_samples,
	const EchoPathVariability& echo_path_variability,
	bool capture_signal_saturation,
	const RenderBuffer& render_buffer,
	std::vector<std::vector<float>>* capture) override;

	// Updates the status on whether echo leakage is detected in the output of the
	// echo remover.
	void UpdateEchoLeakageStatus(bool leakage_detected) override {
	echo_leakage_detected_ = leakage_detected;
	}

	private:
	static int instance_count_;
	const AudioProcessing::Config::EchoCanceller3 config_;
	const Aec3Fft fft_;
	std::unique_ptr<ApmDataDumper> data_dumper_;
	const Aec3Optimization optimization_;
	const int sample_rate_hz_;
	Subtractor subtractor_;
	SuppressionGain suppression_gain_;
	ComfortNoiseGenerator cng_;
	SuppressionFilter suppression_filter_;
	RenderSignalAnalyzer render_signal_analyzer_;
	OutputSelector output_selector_;
	ResidualEchoEstimator residual_echo_estimator_;
	bool echo_leakage_detected_ = false;
	AecState aec_state_;
	EchoRemoverMetrics metrics_;

	RTC_DISALLOW_COPY_AND_ASSIGN(EchoRemoverImpl);
	};

	int EchoRemoverImpl::instance_count_ = 0;

	EchoRemoverImpl::EchoRemoverImpl(
	const AudioProcessing::Config::EchoCanceller3& config,
	int sample_rate_hz)
	: config_(config),
	fft_(),
	data_dumper_(
	new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
	optimization_(DetectOptimization()),
	sample_rate_hz_(sample_rate_hz),
	subtractor_(data_dumper_.get(), optimization_),
	suppression_gain_(config_, optimization_),
	cng_(optimization_),
	suppression_filter_(sample_rate_hz_),
	residual_echo_estimator_(config_),
	aec_state_(config_) {
	RTC_DCHECK(ValidFullBandRate(sample_rate_hz));
	}

	EchoRemoverImpl::~EchoRemoverImpl() = default;

	void EchoRemoverImpl::ProcessCapture(
	const rtc::Optional<size_t>& echo_path_delay_samples,
	const EchoPathVariability& echo_path_variability,
	bool capture_signal_saturation,
	const RenderBuffer& render_buffer,
	std::vector<std::vector<float>>* capture) {
	const std::vector<std::vector<float>>& x = render_buffer.MostRecentBlock();
	std::vector<std::vector<float>>* y = capture;

	RTC_DCHECK(y);
	RTC_DCHECK_EQ(x.size(), NumBandsForRate(sample_rate_hz_));
	RTC_DCHECK_EQ(y->size(), NumBandsForRate(sample_rate_hz_));
	RTC_DCHECK_EQ(x[0].size(), kBlockSize);
	RTC_DCHECK_EQ((*y)[0].size(), kBlockSize);
	const std::vector<float>& x0 = x[0];
	std::vector<float>& y0 = (*y)[0];

	data_dumper_->DumpWav("aec3_echo_remover_capture_input", kBlockSize, &y0[0],
	LowestBandRate(sample_rate_hz_), 1);
	data_dumper_->DumpWav("aec3_echo_remover_render_input", kBlockSize, &x0[0],
	LowestBandRate(sample_rate_hz_), 1);
	data_dumper_->DumpRaw("aec3_echo_remover_capture_input", y0);
	data_dumper_->DumpRaw("aec3_echo_remover_render_input", x0);

	aec_state_.UpdateCaptureSaturation(capture_signal_saturation);

	if (echo_path_variability.AudioPathChanged()) {
	subtractor_.HandleEchoPathChange(echo_path_variability);
	aec_state_.HandleEchoPathChange(echo_path_variability);
	}

	std::array<float, kFftLengthBy2Plus1> Y2;
	std::array<float, kFftLengthBy2Plus1> R2;
	std::array<float, kFftLengthBy2Plus1> S2_linear;
	std::array<float, kFftLengthBy2Plus1> G;
	float high_bands_gain;
	FftData Y;
	FftData comfort_noise;
	FftData high_band_comfort_noise;
	SubtractorOutput subtractor_output;
	FftData& E_main = subtractor_output.E_main;
	auto& E2_main = subtractor_output.E2_main;
	auto& E2_shadow = subtractor_output.E2_shadow;
	auto& e_main = subtractor_output.e_main;

	// Analyze the render signal.
	render_signal_analyzer_.Update(render_buffer, aec_state_.FilterDelay());

	// Perform linear echo cancellation.
	subtractor_.Process(render_buffer, y0, render_signal_analyzer_, aec_state_,
	&subtractor_output);

	// Compute spectra.
	fft_.ZeroPaddedFft(y0, &Y);
	LinearEchoPower(E_main, Y, &S2_linear);
	Y.Spectrum(optimization_, &Y2);

	// Update the AEC state information.
	aec_state_.Update(subtractor_.FilterFrequencyResponse(),
	subtractor_.FilterImpulseResponse(),
	echo_path_delay_samples, render_buffer, E2_main, Y2, x0,
	subtractor_output.s_main, echo_leakage_detected_);

	// Choose the linear output.
	output_selector_.FormLinearOutput(!aec_state_.HeadsetDetected(), e_main, y0);
	data_dumper_->DumpWav("aec3_output_linear", kBlockSize, &y0[0],
	LowestBandRate(sample_rate_hz_), 1);
	data_dumper_->DumpRaw("aec3_output_linear", y0);
	const auto& E2 = output_selector_.UseSubtractorOutput() ? E2_main : Y2;

	// Estimate the residual echo power.
	residual_echo_estimator_.Estimate(output_selector_.UseSubtractorOutput(),
	aec_state_, render_buffer, S2_linear, Y2,
	&R2);

	// Estimate the comfort noise.
	cng_.Compute(aec_state_, Y2, &comfort_noise, &high_band_comfort_noise);

	// A choose and apply echo suppression gain.
	suppression_gain_.GetGain(E2, R2, cng_.NoiseSpectrum(),
	render_signal_analyzer_, aec_state_.SaturatedEcho(),
	x, aec_state_.ForcedZeroGain(), &high_bands_gain,
	&G);
	suppression_filter_.ApplyGain(comfort_noise, high_band_comfort_noise, G,
	high_bands_gain, y);

	// Update the metrics.
	metrics_.Update(aec_state_, cng_.NoiseSpectrum(), G);

	// Update the aec state with the aec output characteristics.
	aec_state_.UpdateWithOutput(y0);

	// Debug outputs for the purpose of development and analysis.
	data_dumper_->DumpWav("aec3_echo_estimate", kBlockSize,
	&subtractor_output.s_main[0],
	LowestBandRate(sample_rate_hz_), 1);
	data_dumper_->DumpRaw("aec3_output", y0);
	data_dumper_->DumpRaw("aec3_narrow_render",
	render_signal_analyzer_.NarrowPeakBand() ? 1 : 0);
	data_dumper_->DumpRaw("aec3_N2", cng_.NoiseSpectrum());
	data_dumper_->DumpRaw("aec3_suppressor_gain", G);
	data_dumper_->DumpWav("aec3_output",
	rtc::ArrayView<const float>(&y0[0], kBlockSize),
	LowestBandRate(sample_rate_hz_), 1);
	data_dumper_->DumpRaw("aec3_using_subtractor_output",
	output_selector_.UseSubtractorOutput() ? 1 : 0);
	data_dumper_->DumpRaw("aec3_E2", E2);
	data_dumper_->DumpRaw("aec3_E2_main", E2_main);
	data_dumper_->DumpRaw("aec3_E2_shadow", E2_shadow);
	data_dumper_->DumpRaw("aec3_S2_linear", S2_linear);
	data_dumper_->DumpRaw("aec3_Y2", Y2);
	data_dumper_->DumpRaw("aec3_X2", render_buffer.Spectrum(0));
	data_dumper_->DumpRaw("aec3_R2", R2);
	data_dumper_->DumpRaw("aec3_erle", aec_state_.Erle());
	data_dumper_->DumpRaw("aec3_erl", aec_state_.Erl());
	data_dumper_->DumpRaw("aec3_active_render", aec_state_.ActiveRender());
	data_dumper_->DumpRaw("aec3_usable_linear_estimate",
	aec_state_.UsableLinearEstimate());
	data_dumper_->DumpRaw(
	"aec3_filter_delay",
	aec_state_.FilterDelay() ? *aec_state_.FilterDelay() : -1);
	data_dumper_->DumpRaw(
	"aec3_external_delay",
	aec_state_.ExternalDelay() ? *aec_state_.ExternalDelay() : -1);
	data_dumper_->DumpRaw("aec3_capture_saturation",
	aec_state_.SaturatedCapture() ? 1 : 0);
	}

	} // namespace

	EchoRemover* EchoRemover::Create(
	const AudioProcessing::Config::EchoCanceller3& config,
	int sample_rate_hz) {
	return new EchoRemoverImpl(config, sample_rate_hz);
	}

	} // namespace webrtc