f6aa572e36
This CL introduces the handling of multiple microphone channels in the EchoRemover layer. The implementation is done such as to support an arbitrary number of channels in a way that balances stack and heap-space usage. Bug: webrtc:10913 Change-Id: I475369de6c463b8fe2d7e53799d7322eefb6938f Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/151647 Commit-Queue: Per Åhgren <peah@webrtc.org> Reviewed-by: Sam Zackrisson <saza@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29140}
495 lines
20 KiB
C++
495 lines
20 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 "modules/audio_processing/aec3/echo_remover.h"
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#include <math.h>
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#include <stddef.h>
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#include <algorithm>
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#include <array>
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#include <cmath>
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#include <memory>
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#include "api/array_view.h"
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#include "modules/audio_processing/aec3/aec3_common.h"
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#include "modules/audio_processing/aec3/aec3_fft.h"
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#include "modules/audio_processing/aec3/aec_state.h"
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#include "modules/audio_processing/aec3/comfort_noise_generator.h"
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#include "modules/audio_processing/aec3/echo_path_variability.h"
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#include "modules/audio_processing/aec3/echo_remover_metrics.h"
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#include "modules/audio_processing/aec3/fft_data.h"
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#include "modules/audio_processing/aec3/render_buffer.h"
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#include "modules/audio_processing/aec3/render_signal_analyzer.h"
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#include "modules/audio_processing/aec3/residual_echo_estimator.h"
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#include "modules/audio_processing/aec3/subtractor.h"
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#include "modules/audio_processing/aec3/subtractor_output.h"
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#include "modules/audio_processing/aec3/suppression_filter.h"
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#include "modules/audio_processing/aec3/suppression_gain.h"
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#include "modules/audio_processing/logging/apm_data_dumper.h"
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#include "rtc_base/atomic_ops.h"
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#include "rtc_base/checks.h"
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#include "rtc_base/logging.h"
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namespace webrtc {
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namespace {
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// Maximum number of channels for which the capture channel data is stored on
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// the stack. If the number of channels are larger than this, they are stored
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// using scratch memory that is pre-allocated on the heap. The reason for this
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// partitioning is not to waste heap space for handling the more common numbers
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// of channels, while at the same time not limiting the support for higher
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// numbers of channels by enforcing the capture channel data to be stored on the
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// stack using a fixed maximum value.
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constexpr size_t kMaxNumChannelsOnStack = 2;
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// Chooses the number of channels to store on the heap when that is required due
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// to the number of capture channels being larger than the pre-defined number
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// of channels to store on the stack.
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size_t NumChannelsOnHeap(size_t num_capture_channels) {
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return num_capture_channels > kMaxNumChannelsOnStack ? num_capture_channels
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: 0;
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}
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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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// Fades between two input signals using a fix-sized transition.
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void SignalTransition(rtc::ArrayView<const float> from,
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rtc::ArrayView<const float> to,
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rtc::ArrayView<float> out) {
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constexpr size_t kTransitionSize = 30;
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constexpr float kOneByTransitionSizePlusOne = 1.f / (kTransitionSize + 1);
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RTC_DCHECK_EQ(from.size(), to.size());
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RTC_DCHECK_EQ(from.size(), out.size());
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RTC_DCHECK_LE(kTransitionSize, out.size());
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for (size_t k = 0; k < kTransitionSize; ++k) {
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float a = (k + 1) * kOneByTransitionSizePlusOne;
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out[k] = a * to[k] + (1.f - a) * from[k];
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}
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std::copy(to.begin() + kTransitionSize, to.end(),
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out.begin() + kTransitionSize);
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}
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// Computes a windowed (square root Hanning) padded FFT and updates the related
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// memory.
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void WindowedPaddedFft(const Aec3Fft& fft,
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rtc::ArrayView<const float> v,
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rtc::ArrayView<float> v_old,
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FftData* V) {
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fft.PaddedFft(v, v_old, Aec3Fft::Window::kSqrtHanning, V);
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std::copy(v.begin(), v.end(), v_old.begin());
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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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EchoRemoverImpl(const EchoCanceller3Config& config,
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int sample_rate_hz,
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size_t num_render_channels,
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size_t num_capture_channels);
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~EchoRemoverImpl() override;
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EchoRemoverImpl(const EchoRemoverImpl&) = delete;
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EchoRemoverImpl& operator=(const EchoRemoverImpl&) = delete;
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void GetMetrics(EchoControl::Metrics* metrics) const 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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EchoPathVariability echo_path_variability,
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bool capture_signal_saturation,
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const absl::optional<DelayEstimate>& external_delay,
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RenderBuffer* render_buffer,
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std::vector<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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// Selects which of the shadow and main linear filter outputs that is most
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// appropriate to pass to the suppressor and forms the linear filter output by
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// smoothly transition between those.
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void FormLinearFilterOutput(const SubtractorOutput& subtractor_output,
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rtc::ArrayView<float> output);
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static int instance_count_;
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const EchoCanceller3Config config_;
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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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const size_t num_render_channels_;
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const size_t num_capture_channels_;
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const bool use_shadow_filter_output_;
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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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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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std::array<float, kFftLengthBy2> e_old_;
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std::array<float, kFftLengthBy2> x_old_;
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std::array<float, kFftLengthBy2> y_old_;
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size_t block_counter_ = 0;
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int gain_change_hangover_ = 0;
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bool main_filter_output_last_selected_ = true;
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bool linear_filter_output_last_selected_ = true;
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std::vector<std::array<float, kFftLengthBy2Plus1>> Y2_heap_;
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std::vector<std::array<float, kFftLengthBy2Plus1>> E2_heap_;
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std::vector<std::array<float, kFftLengthBy2Plus1>> R2_heap_;
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std::vector<std::array<float, kFftLengthBy2Plus1>> S2_linear_heap_;
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std::vector<FftData> Y_heap_;
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std::vector<FftData> E_heap_;
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std::vector<FftData> comfort_noise_heap_;
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std::vector<FftData> high_band_comfort_noise_heap_;
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std::vector<SubtractorOutput> subtractor_output_heap_;
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};
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int EchoRemoverImpl::instance_count_ = 0;
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EchoRemoverImpl::EchoRemoverImpl(const EchoCanceller3Config& config,
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int sample_rate_hz,
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size_t num_render_channels,
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size_t num_capture_channels)
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: config_(config),
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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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num_render_channels_(num_render_channels),
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num_capture_channels_(num_capture_channels),
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use_shadow_filter_output_(
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config_.filter.enable_shadow_filter_output_usage),
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subtractor_(config,
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num_render_channels_,
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num_capture_channels_,
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data_dumper_.get(),
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optimization_),
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suppression_gain_(config_, optimization_, sample_rate_hz),
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cng_(optimization_),
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suppression_filter_(optimization_, sample_rate_hz_),
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render_signal_analyzer_(config_),
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residual_echo_estimator_(config_),
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aec_state_(config_),
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Y2_heap_(NumChannelsOnHeap(num_capture_channels_)),
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E2_heap_(NumChannelsOnHeap(num_capture_channels_)),
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R2_heap_(NumChannelsOnHeap(num_capture_channels_)),
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S2_linear_heap_(NumChannelsOnHeap(num_capture_channels_)),
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Y_heap_(NumChannelsOnHeap(num_capture_channels_)),
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E_heap_(NumChannelsOnHeap(num_capture_channels_)),
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comfort_noise_heap_(NumChannelsOnHeap(num_capture_channels_)),
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high_band_comfort_noise_heap_(NumChannelsOnHeap(num_capture_channels_)),
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subtractor_output_heap_(NumChannelsOnHeap(num_capture_channels_)) {
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RTC_DCHECK(ValidFullBandRate(sample_rate_hz));
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x_old_.fill(0.f);
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y_old_.fill(0.f);
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e_old_.fill(0.f);
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}
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EchoRemoverImpl::~EchoRemoverImpl() = default;
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void EchoRemoverImpl::GetMetrics(EchoControl::Metrics* metrics) const {
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// Echo return loss (ERL) is inverted to go from gain to attenuation.
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metrics->echo_return_loss = -10.0 * std::log10(aec_state_.ErlTimeDomain());
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metrics->echo_return_loss_enhancement =
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Log2TodB(aec_state_.FullBandErleLog2());
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}
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void EchoRemoverImpl::ProcessCapture(
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EchoPathVariability echo_path_variability,
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bool capture_signal_saturation,
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const absl::optional<DelayEstimate>& external_delay,
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RenderBuffer* render_buffer,
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std::vector<std::vector<std::vector<float>>>* capture) {
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++block_counter_;
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const std::vector<std::vector<std::vector<float>>>& x =
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render_buffer->Block(0);
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std::vector<std::vector<std::vector<float>>>* y = capture;
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RTC_DCHECK(render_buffer);
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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(), num_render_channels_);
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RTC_DCHECK_EQ((*y)[0].size(), num_capture_channels_);
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RTC_DCHECK_EQ(x[0][0].size(), kBlockSize);
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RTC_DCHECK_EQ((*y)[0][0].size(), kBlockSize);
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// Stack allocated data to use when the number of channels is low.
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std::array<std::array<float, kFftLengthBy2Plus1>, kMaxNumChannelsOnStack>
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Y2_stack;
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std::array<std::array<float, kFftLengthBy2Plus1>, kMaxNumChannelsOnStack>
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E2_stack;
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std::array<std::array<float, kFftLengthBy2Plus1>, kMaxNumChannelsOnStack>
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R2_stack;
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std::array<std::array<float, kFftLengthBy2Plus1>, kMaxNumChannelsOnStack>
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S2_linear_stack;
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std::array<FftData, kMaxNumChannelsOnStack> Y_stack;
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std::array<FftData, kMaxNumChannelsOnStack> E_stack;
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std::array<FftData, kMaxNumChannelsOnStack> comfort_noise_stack;
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std::array<FftData, kMaxNumChannelsOnStack> high_band_comfort_noise_stack;
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std::array<SubtractorOutput, kMaxNumChannelsOnStack> subtractor_output_stack;
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rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> Y2(
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Y2_stack.data(), num_capture_channels_);
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rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> E2(
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E2_stack.data(), num_capture_channels_);
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rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> R2(
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R2_stack.data(), num_capture_channels_);
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rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> S2_linear(
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S2_linear_stack.data(), num_capture_channels_);
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rtc::ArrayView<FftData> Y(Y_stack.data(), num_capture_channels_);
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rtc::ArrayView<FftData> E(E_stack.data(), num_capture_channels_);
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rtc::ArrayView<FftData> comfort_noise(comfort_noise_stack.data(),
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num_capture_channels_);
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rtc::ArrayView<FftData> high_band_comfort_noise(
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high_band_comfort_noise_stack.data(), num_capture_channels_);
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rtc::ArrayView<SubtractorOutput> subtractor_output(
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subtractor_output_stack.data(), num_capture_channels_);
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if (NumChannelsOnHeap(num_capture_channels_) > 0) {
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// If the stack-allocated space is too small, use the heap for storing the
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// microphone data.
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Y2 = rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>>(
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Y2_heap_.data(), num_capture_channels_);
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E2 = rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>>(
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E2_heap_.data(), num_capture_channels_);
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R2 = rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>>(
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R2_heap_.data(), num_capture_channels_);
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S2_linear = rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>>(
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S2_linear_heap_.data(), num_capture_channels_);
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Y = rtc::ArrayView<FftData>(Y_heap_.data(), num_capture_channels_);
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E = rtc::ArrayView<FftData>(E_heap_.data(), num_capture_channels_);
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comfort_noise = rtc::ArrayView<FftData>(comfort_noise_heap_.data(),
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num_capture_channels_);
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high_band_comfort_noise = rtc::ArrayView<FftData>(
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high_band_comfort_noise_heap_.data(), num_capture_channels_);
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subtractor_output = rtc::ArrayView<SubtractorOutput>(
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subtractor_output_heap_.data(), num_capture_channels_);
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}
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const std::vector<float>& x0 = x[0][0];
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std::vector<float>& y0 = (*y)[0][0];
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data_dumper_->DumpWav("aec3_echo_remover_capture_input", kBlockSize, &y0[0],
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16000, 1);
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data_dumper_->DumpWav("aec3_echo_remover_render_input", kBlockSize, &x0[0],
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16000, 1);
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data_dumper_->DumpRaw("aec3_echo_remover_capture_input", y0);
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data_dumper_->DumpRaw("aec3_echo_remover_render_input", x0);
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aec_state_.UpdateCaptureSaturation(capture_signal_saturation);
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if (echo_path_variability.AudioPathChanged()) {
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// Ensure that the gain change is only acted on once per frame.
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if (echo_path_variability.gain_change) {
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if (gain_change_hangover_ == 0) {
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constexpr int kMaxBlocksPerFrame = 3;
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gain_change_hangover_ = kMaxBlocksPerFrame;
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RTC_LOG(LS_INFO) << "Gain change detected at block " << block_counter_;
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} else {
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echo_path_variability.gain_change = false;
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}
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}
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subtractor_.HandleEchoPathChange(echo_path_variability);
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aec_state_.HandleEchoPathChange(echo_path_variability);
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if (echo_path_variability.delay_change !=
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EchoPathVariability::DelayAdjustment::kNone) {
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suppression_gain_.SetInitialState(true);
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}
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}
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if (gain_change_hangover_ > 0) {
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--gain_change_hangover_;
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}
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float high_bands_gain;
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std::array<float, kFftLengthBy2Plus1> G;
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// Analyze the render signal.
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render_signal_analyzer_.Update(*render_buffer,
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aec_state_.FilterDelayBlocks());
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// Perform linear echo cancellation.
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if (aec_state_.TransitionTriggered()) {
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subtractor_.ExitInitialState();
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suppression_gain_.SetInitialState(false);
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}
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// If the delay is known, use the echo subtractor.
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subtractor_.Process(*render_buffer, y0, render_signal_analyzer_, aec_state_,
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&subtractor_output[0]);
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std::array<float, kBlockSize> e;
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FormLinearFilterOutput(subtractor_output[0], e);
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// Compute spectra.
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WindowedPaddedFft(fft_, y0, y_old_, &Y[0]);
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WindowedPaddedFft(fft_, e, e_old_, &E[0]);
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LinearEchoPower(E[0], Y[0], &S2_linear[0]);
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Y[0].Spectrum(optimization_, Y2[0]);
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E[0].Spectrum(optimization_, E2[0]);
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// Update the AEC state information.
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aec_state_.Update(external_delay, subtractor_.FilterFrequencyResponse(),
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subtractor_.FilterImpulseResponse(), *render_buffer, E2[0],
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Y2[0], subtractor_output[0], y0);
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// Choose the linear output.
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data_dumper_->DumpWav("aec3_output_linear2", kBlockSize, &e[0], 16000, 1);
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if (aec_state_.UseLinearFilterOutput()) {
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if (!linear_filter_output_last_selected_) {
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SignalTransition(y0, e, y0);
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} else {
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std::copy(e.begin(), e.end(), y0.begin());
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}
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} else {
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if (linear_filter_output_last_selected_) {
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SignalTransition(e, y0, y0);
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}
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}
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linear_filter_output_last_selected_ = aec_state_.UseLinearFilterOutput();
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const auto& Y_fft = aec_state_.UseLinearFilterOutput() ? E[0] : Y[0];
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data_dumper_->DumpWav("aec3_output_linear", kBlockSize, &y0[0], 16000, 1);
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// Estimate the residual echo power.
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residual_echo_estimator_.Estimate(aec_state_, *render_buffer, S2_linear[0],
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Y2[0], &R2[0]);
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// Estimate the comfort noise.
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cng_.Compute(aec_state_, Y2[0], &comfort_noise[0],
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&high_band_comfort_noise[0]);
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// Suppressor echo estimate.
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const auto& echo_spectrum =
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aec_state_.UsableLinearEstimate() ? S2_linear[0] : R2[0];
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// Suppressor nearend estimate.
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std::array<float, kFftLengthBy2Plus1> nearend_spectrum_bounded;
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if (aec_state_.UsableLinearEstimate()) {
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std::transform(E2[0].begin(), E2[0].end(), Y2[0].begin(),
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nearend_spectrum_bounded.begin(),
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[](float a, float b) { return std::min(a, b); });
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}
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const auto& nearend_spectrum =
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aec_state_.UsableLinearEstimate() ? nearend_spectrum_bounded : Y2[0];
|
|
|
|
// Compute and apply the suppression gain.
|
|
suppression_gain_.GetGain(nearend_spectrum, echo_spectrum, R2[0],
|
|
cng_.NoiseSpectrum(), render_signal_analyzer_,
|
|
aec_state_, x, &high_bands_gain, &G);
|
|
|
|
suppression_filter_.ApplyGain(comfort_noise[0], high_band_comfort_noise[0], G,
|
|
high_bands_gain, Y_fft, y);
|
|
|
|
// Update the metrics.
|
|
metrics_.Update(aec_state_, cng_.NoiseSpectrum(), G);
|
|
|
|
// Debug outputs for the purpose of development and analysis.
|
|
data_dumper_->DumpWav("aec3_echo_estimate", kBlockSize,
|
|
&subtractor_output[0].s_main[0], 16000, 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), 16000, 1);
|
|
data_dumper_->DumpRaw("aec3_using_subtractor_output[0]",
|
|
aec_state_.UseLinearFilterOutput() ? 1 : 0);
|
|
data_dumper_->DumpRaw("aec3_E2", E2[0]);
|
|
data_dumper_->DumpRaw("aec3_S2_linear", S2_linear[0]);
|
|
data_dumper_->DumpRaw("aec3_Y2", Y2[0]);
|
|
data_dumper_->DumpRaw(
|
|
"aec3_X2",
|
|
render_buffer->Spectrum(aec_state_.FilterDelayBlocks(), /*channel=*/0));
|
|
data_dumper_->DumpRaw("aec3_R2", R2[0]);
|
|
data_dumper_->DumpRaw("aec3_R2_reverb",
|
|
residual_echo_estimator_.GetReverbPowerSpectrum());
|
|
data_dumper_->DumpRaw("aec3_filter_delay", aec_state_.FilterDelayBlocks());
|
|
data_dumper_->DumpRaw("aec3_capture_saturation",
|
|
aec_state_.SaturatedCapture() ? 1 : 0);
|
|
}
|
|
|
|
void EchoRemoverImpl::FormLinearFilterOutput(
|
|
const SubtractorOutput& subtractor_output,
|
|
rtc::ArrayView<float> output) {
|
|
RTC_DCHECK_EQ(subtractor_output.e_main.size(), output.size());
|
|
RTC_DCHECK_EQ(subtractor_output.e_shadow.size(), output.size());
|
|
bool use_main_output = true;
|
|
if (use_shadow_filter_output_) {
|
|
// As the output of the main adaptive filter generally should be better
|
|
// than the shadow filter output, add a margin and threshold for when
|
|
// choosing the shadow filter output.
|
|
if (subtractor_output.e2_shadow < 0.9f * subtractor_output.e2_main &&
|
|
subtractor_output.y2 > 30.f * 30.f * kBlockSize &&
|
|
(subtractor_output.s2_main > 60.f * 60.f * kBlockSize ||
|
|
subtractor_output.s2_shadow > 60.f * 60.f * kBlockSize)) {
|
|
use_main_output = false;
|
|
} else {
|
|
// If the main filter is diverged, choose the filter output that has the
|
|
// lowest power.
|
|
if (subtractor_output.e2_shadow < subtractor_output.e2_main &&
|
|
subtractor_output.y2 < subtractor_output.e2_main) {
|
|
use_main_output = false;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (use_main_output) {
|
|
if (!main_filter_output_last_selected_) {
|
|
SignalTransition(subtractor_output.e_shadow, subtractor_output.e_main,
|
|
output);
|
|
} else {
|
|
std::copy(subtractor_output.e_main.begin(),
|
|
subtractor_output.e_main.end(), output.begin());
|
|
}
|
|
} else {
|
|
if (main_filter_output_last_selected_) {
|
|
SignalTransition(subtractor_output.e_main, subtractor_output.e_shadow,
|
|
output);
|
|
} else {
|
|
std::copy(subtractor_output.e_shadow.begin(),
|
|
subtractor_output.e_shadow.end(), output.begin());
|
|
}
|
|
}
|
|
main_filter_output_last_selected_ = use_main_output;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
EchoRemover* EchoRemover::Create(const EchoCanceller3Config& config,
|
|
int sample_rate_hz,
|
|
size_t num_render_channels,
|
|
size_t num_capture_channels) {
|
|
return new EchoRemoverImpl(config, sample_rate_hz, num_render_channels,
|
|
num_capture_channels);
|
|
}
|
|
|
|
} // namespace webrtc
|