6d822adac4
During the first few capture frames, there is no way for the AEC to tell whether there is echo in the capture signal as the echo removal functionality in the AEC has not yet seen any render signal. To avoid initial echo bursts due to this, this CL adds functionality for forcing the echo suppression gain to zero during the first 50 blocks (200 ms) after call start and after a reported echo path change. BUG=webrtc:6018 Review-Url: https://codereview.webrtc.org/2808733002 Cr-Commit-Position: refs/heads/master@{#17624}
229 lines
8.9 KiB
C++
229 lines
8.9 KiB
C++
/*
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* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "webrtc/modules/audio_processing/aec3/echo_remover.h"
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#include <math.h>
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#include <algorithm>
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#include <memory>
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#include <numeric>
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#include <string>
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#include "webrtc/base/array_view.h"
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#include "webrtc/base/atomicops.h"
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#include "webrtc/base/constructormagic.h"
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#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
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#include "webrtc/modules/audio_processing/aec3/aec_state.h"
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#include "webrtc/modules/audio_processing/aec3/comfort_noise_generator.h"
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#include "webrtc/modules/audio_processing/aec3/echo_path_variability.h"
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#include "webrtc/modules/audio_processing/aec3/echo_remover_metrics.h"
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#include "webrtc/modules/audio_processing/aec3/fft_data.h"
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#include "webrtc/modules/audio_processing/aec3/output_selector.h"
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#include "webrtc/modules/audio_processing/aec3/render_buffer.h"
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#include "webrtc/modules/audio_processing/aec3/render_delay_buffer.h"
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#include "webrtc/modules/audio_processing/aec3/residual_echo_estimator.h"
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#include "webrtc/modules/audio_processing/aec3/subtractor.h"
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#include "webrtc/modules/audio_processing/aec3/suppression_filter.h"
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#include "webrtc/modules/audio_processing/aec3/suppression_gain.h"
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#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
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namespace webrtc {
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namespace {
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void LinearEchoPower(const FftData& E,
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const FftData& Y,
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std::array<float, kFftLengthBy2Plus1>* S2) {
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for (size_t k = 0; k < E.re.size(); ++k) {
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(*S2)[k] = (Y.re[k] - E.re[k]) * (Y.re[k] - E.re[k]) +
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(Y.im[k] - E.im[k]) * (Y.im[k] - E.im[k]);
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}
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}
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// Class for removing the echo from the capture signal.
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class EchoRemoverImpl final : public EchoRemover {
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public:
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explicit EchoRemoverImpl(int sample_rate_hz);
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~EchoRemoverImpl() override;
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// Removes the echo from a block of samples from the capture signal. The
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// supplied render signal is assumed to be pre-aligned with the capture
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// signal.
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void ProcessCapture(
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const rtc::Optional<size_t>& external_echo_path_delay_estimate,
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const EchoPathVariability& echo_path_variability,
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bool capture_signal_saturation,
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const RenderBuffer& render_buffer,
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std::vector<std::vector<float>>* capture) override;
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// Updates the status on whether echo leakage is detected in the output of the
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// echo remover.
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void UpdateEchoLeakageStatus(bool leakage_detected) override {
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echo_leakage_detected_ = leakage_detected;
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}
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private:
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static int instance_count_;
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const Aec3Fft fft_;
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std::unique_ptr<ApmDataDumper> data_dumper_;
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const Aec3Optimization optimization_;
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const int sample_rate_hz_;
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Subtractor subtractor_;
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SuppressionGain suppression_gain_;
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ComfortNoiseGenerator cng_;
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SuppressionFilter suppression_filter_;
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RenderSignalAnalyzer render_signal_analyzer_;
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OutputSelector output_selector_;
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ResidualEchoEstimator residual_echo_estimator_;
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bool echo_leakage_detected_ = false;
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AecState aec_state_;
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EchoRemoverMetrics metrics_;
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RTC_DISALLOW_COPY_AND_ASSIGN(EchoRemoverImpl);
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};
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int EchoRemoverImpl::instance_count_ = 0;
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EchoRemoverImpl::EchoRemoverImpl(int sample_rate_hz)
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: fft_(),
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data_dumper_(
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new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
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optimization_(DetectOptimization()),
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sample_rate_hz_(sample_rate_hz),
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subtractor_(data_dumper_.get(), optimization_),
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suppression_gain_(optimization_),
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cng_(optimization_),
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suppression_filter_(sample_rate_hz_) {
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RTC_DCHECK(ValidFullBandRate(sample_rate_hz));
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}
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EchoRemoverImpl::~EchoRemoverImpl() = default;
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void EchoRemoverImpl::ProcessCapture(
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const rtc::Optional<size_t>& echo_path_delay_samples,
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const EchoPathVariability& echo_path_variability,
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bool capture_signal_saturation,
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const RenderBuffer& render_buffer,
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std::vector<std::vector<float>>* capture) {
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const std::vector<std::vector<float>>& x = render_buffer.MostRecentBlock();
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std::vector<std::vector<float>>* y = capture;
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RTC_DCHECK(y);
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RTC_DCHECK_EQ(x.size(), NumBandsForRate(sample_rate_hz_));
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RTC_DCHECK_EQ(y->size(), NumBandsForRate(sample_rate_hz_));
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RTC_DCHECK_EQ(x[0].size(), kBlockSize);
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RTC_DCHECK_EQ((*y)[0].size(), kBlockSize);
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const std::vector<float>& x0 = x[0];
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std::vector<float>& y0 = (*y)[0];
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data_dumper_->DumpWav("aec3_echo_remover_capture_input", kBlockSize, &y0[0],
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LowestBandRate(sample_rate_hz_), 1);
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data_dumper_->DumpWav("aec3_echo_remover_render_input", kBlockSize, &x0[0],
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LowestBandRate(sample_rate_hz_), 1);
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aec_state_.UpdateCaptureSaturation(capture_signal_saturation);
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if (echo_path_variability.AudioPathChanged()) {
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subtractor_.HandleEchoPathChange(echo_path_variability);
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aec_state_.HandleEchoPathChange(echo_path_variability);
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}
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std::array<float, kFftLengthBy2Plus1> Y2;
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std::array<float, kFftLengthBy2Plus1> R2;
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std::array<float, kFftLengthBy2Plus1> S2_linear;
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std::array<float, kFftLengthBy2Plus1> G;
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float high_bands_gain;
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FftData Y;
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FftData comfort_noise;
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FftData high_band_comfort_noise;
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SubtractorOutput subtractor_output;
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FftData& E_main = subtractor_output.E_main;
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auto& E2_main = subtractor_output.E2_main;
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auto& E2_shadow = subtractor_output.E2_shadow;
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auto& e_main = subtractor_output.e_main;
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// Analyze the render signal.
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render_signal_analyzer_.Update(render_buffer, aec_state_.FilterDelay());
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// Perform linear echo cancellation.
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subtractor_.Process(render_buffer, y0, render_signal_analyzer_, aec_state_,
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&subtractor_output);
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// Compute spectra.
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fft_.ZeroPaddedFft(y0, &Y);
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LinearEchoPower(E_main, Y, &S2_linear);
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Y.Spectrum(optimization_, &Y2);
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// Update the AEC state information.
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aec_state_.Update(subtractor_.FilterFrequencyResponse(),
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echo_path_delay_samples, render_buffer, E2_main, Y2, x0,
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echo_leakage_detected_);
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// Choose the linear output.
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output_selector_.FormLinearOutput(!aec_state_.HeadsetDetected(), e_main, y0);
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data_dumper_->DumpWav("aec3_output_linear", kBlockSize, &y0[0],
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LowestBandRate(sample_rate_hz_), 1);
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const auto& E2 = output_selector_.UseSubtractorOutput() ? E2_main : Y2;
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// Estimate the residual echo power.
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residual_echo_estimator_.Estimate(output_selector_.UseSubtractorOutput(),
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aec_state_, render_buffer, S2_linear, Y2,
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&R2);
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// Estimate the comfort noise.
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cng_.Compute(aec_state_, Y2, &comfort_noise, &high_band_comfort_noise);
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// A choose and apply echo suppression gain.
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suppression_gain_.GetGain(E2, R2, cng_.NoiseSpectrum(),
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aec_state_.SaturatedEcho(), x, y->size(),
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aec_state_.ForcedZeroGain(), &high_bands_gain, &G);
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suppression_filter_.ApplyGain(comfort_noise, high_band_comfort_noise, G,
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high_bands_gain, y);
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// Update the metrics.
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metrics_.Update(aec_state_, cng_.NoiseSpectrum(), G);
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// Debug outputs for the purpose of development and analysis.
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data_dumper_->DumpRaw("aec3_N2", cng_.NoiseSpectrum());
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data_dumper_->DumpRaw("aec3_suppressor_gain", G);
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data_dumper_->DumpWav("aec3_output",
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rtc::ArrayView<const float>(&y0[0], kBlockSize),
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LowestBandRate(sample_rate_hz_), 1);
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data_dumper_->DumpRaw("aec3_using_subtractor_output",
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output_selector_.UseSubtractorOutput() ? 1 : 0);
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data_dumper_->DumpRaw("aec3_E2", E2);
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data_dumper_->DumpRaw("aec3_E2_main", E2_main);
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data_dumper_->DumpRaw("aec3_E2_shadow", E2_shadow);
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data_dumper_->DumpRaw("aec3_S2_linear", S2_linear);
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data_dumper_->DumpRaw("aec3_Y2", Y2);
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data_dumper_->DumpRaw("aec3_X2", render_buffer.Spectrum(0));
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data_dumper_->DumpRaw("aec3_R2", R2);
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data_dumper_->DumpRaw("aec3_erle", aec_state_.Erle());
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data_dumper_->DumpRaw("aec3_erl", aec_state_.Erl());
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data_dumper_->DumpRaw("aec3_active_render", aec_state_.ActiveRender());
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data_dumper_->DumpRaw("aec3_usable_linear_estimate",
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aec_state_.UsableLinearEstimate());
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data_dumper_->DumpRaw(
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"aec3_filter_delay",
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aec_state_.FilterDelay() ? *aec_state_.FilterDelay() : -1);
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data_dumper_->DumpRaw(
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"aec3_external_delay",
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aec_state_.ExternalDelay() ? *aec_state_.ExternalDelay() : -1);
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data_dumper_->DumpRaw("aec3_capture_saturation",
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aec_state_.SaturatedCapture() ? 1 : 0);
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}
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} // namespace
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EchoRemover* EchoRemover::Create(int sample_rate_hz) {
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return new EchoRemoverImpl(sample_rate_hz);
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}
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} // namespace webrtc
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