modules/audio_processing/aec3/aec_state.cc - src - 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 "modules/audio_processing/aec3/aec_state.h"

 #include <math.h>

 #include <algorithm>
 #include <numeric>
 #include <optional>
 #include <vector>

 #include "api/array_view.h"
 #include "modules/audio_processing/aec3/aec3_common.h"
 #include "modules/audio_processing/logging/apm_data_dumper.h"
 #include "rtc_base/checks.h"
 #include "system_wrappers/include/field_trial.h"

 namespace webrtc {
 namespace {

 bool DeactivateInitialStateResetAtEchoPathChange() {
   return field_trial::IsEnabled(
       "WebRTC-Aec3DeactivateInitialStateResetKillSwitch");
 }

 bool FullResetAtEchoPathChange() {
   return !field_trial::IsEnabled("WebRTC-Aec3AecStateFullResetKillSwitch");
 }

 bool SubtractorAnalyzerResetAtEchoPathChange() {
   return !field_trial::IsEnabled(
       "WebRTC-Aec3AecStateSubtractorAnalyzerResetKillSwitch");
 }

 void ComputeAvgRenderReverb(
     const SpectrumBuffer& spectrum_buffer,
     int delay_blocks,
     float reverb_decay,
     ReverbModel* reverb_model,
     rtc::ArrayView<float, kFftLengthBy2Plus1> reverb_power_spectrum) {
   RTC_DCHECK(reverb_model);
   const size_t num_render_channels = spectrum_buffer.buffer[0].size();
   int idx_at_delay =
       spectrum_buffer.OffsetIndex(spectrum_buffer.read, delay_blocks);
   int idx_past = spectrum_buffer.IncIndex(idx_at_delay);

   std::array<float, kFftLengthBy2Plus1> X2_data;
   rtc::ArrayView<const float> X2;
   if (num_render_channels > 1) {
     auto average_channels =
         [](size_t num_render_channels,
            rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>>
                spectrum_band_0,
            rtc::ArrayView<float, kFftLengthBy2Plus1> render_power) {
           std::fill(render_power.begin(), render_power.end(), 0.f);
           for (size_t ch = 0; ch < num_render_channels; ++ch) {
             for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
               render_power[k] += spectrum_band_0[ch][k];
             }
           }
           const float normalizer = 1.f / num_render_channels;
           for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
             render_power[k] *= normalizer;
           }
         };
     average_channels(num_render_channels, spectrum_buffer.buffer[idx_past],
                      X2_data);
     reverb_model->UpdateReverbNoFreqShaping(
         X2_data, /*power_spectrum_scaling=*/1.0f, reverb_decay);

     average_channels(num_render_channels, spectrum_buffer.buffer[idx_at_delay],
                      X2_data);
     X2 = X2_data;
   } else {
     reverb_model->UpdateReverbNoFreqShaping(
         spectrum_buffer.buffer[idx_past][/*channel=*/0],
         /*power_spectrum_scaling=*/1.0f, reverb_decay);

     X2 = spectrum_buffer.buffer[idx_at_delay][/*channel=*/0];
   }

   rtc::ArrayView<const float, kFftLengthBy2Plus1> reverb_power =
       reverb_model->reverb();
   for (size_t k = 0; k < X2.size(); ++k) {
     reverb_power_spectrum[k] = X2[k] + reverb_power[k];
   }
 }

 }  // namespace

 std::atomic<int> AecState::instance_count_(0);

 void AecState::GetResidualEchoScaling(
     rtc::ArrayView<float> residual_scaling) const {
   bool filter_has_had_time_to_converge;
   if (config_.filter.conservative_initial_phase) {
     filter_has_had_time_to_converge =
         strong_not_saturated_render_blocks_ >= 1.5f * kNumBlocksPerSecond;
   } else {
     filter_has_had_time_to_converge =
         strong_not_saturated_render_blocks_ >= 0.8f * kNumBlocksPerSecond;
   }
   echo_audibility_.GetResidualEchoScaling(filter_has_had_time_to_converge,
                                           residual_scaling);
 }

 AecState::AecState(const EchoCanceller3Config& config,
                    size_t num_capture_channels)
     : data_dumper_(new ApmDataDumper(instance_count_.fetch_add(1) + 1)),
       config_(config),
       num_capture_channels_(num_capture_channels),
       deactivate_initial_state_reset_at_echo_path_change_(
           DeactivateInitialStateResetAtEchoPathChange()),
       full_reset_at_echo_path_change_(FullResetAtEchoPathChange()),
       subtractor_analyzer_reset_at_echo_path_change_(
           SubtractorAnalyzerResetAtEchoPathChange()),
       initial_state_(config_),
       delay_state_(config_, num_capture_channels_),
       transparent_state_(TransparentMode::Create(config_)),
       filter_quality_state_(config_, num_capture_channels_),
       erl_estimator_(2 * kNumBlocksPerSecond),
       erle_estimator_(2 * kNumBlocksPerSecond, config_, num_capture_channels_),
       filter_analyzer_(config_, num_capture_channels_),
       echo_audibility_(
           config_.echo_audibility.use_stationarity_properties_at_init),
       reverb_model_estimator_(config_, num_capture_channels_),
       subtractor_output_analyzer_(num_capture_channels_) {}

 AecState::~AecState() = default;

 void AecState::HandleEchoPathChange(
     const EchoPathVariability& echo_path_variability) {
   const auto full_reset = [&]() {
     filter_analyzer_.Reset();
     capture_signal_saturation_ = false;
     strong_not_saturated_render_blocks_ = 0;
     blocks_with_active_render_ = 0;
     if (!deactivate_initial_state_reset_at_echo_path_change_) {
       initial_state_.Reset();
     }
     if (transparent_state_) {
       transparent_state_->Reset();
     }
     erle_estimator_.Reset(true);
     erl_estimator_.Reset();
     filter_quality_state_.Reset();
   };

   // TODO(peah): Refine the reset scheme according to the type of gain and
   // delay adjustment.

   if (full_reset_at_echo_path_change_ &&
       echo_path_variability.delay_change !=
           EchoPathVariability::DelayAdjustment::kNone) {
     full_reset();
   } else if (echo_path_variability.gain_change) {
     erle_estimator_.Reset(false);
   }
   if (subtractor_analyzer_reset_at_echo_path_change_) {
     subtractor_output_analyzer_.HandleEchoPathChange();
   }
 }

 void AecState::Update(
     const std::optional<DelayEstimate>& external_delay,
     rtc::ArrayView<const std::vector<std::array<float, kFftLengthBy2Plus1>>>
         adaptive_filter_frequency_responses,
     rtc::ArrayView<const std::vector<float>> adaptive_filter_impulse_responses,
     const RenderBuffer& render_buffer,
     rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> E2_refined,
     rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Y2,
     rtc::ArrayView<const SubtractorOutput> subtractor_output) {
   RTC_DCHECK_EQ(num_capture_channels_, Y2.size());
   RTC_DCHECK_EQ(num_capture_channels_, subtractor_output.size());
   RTC_DCHECK_EQ(num_capture_channels_,
                 adaptive_filter_frequency_responses.size());
   RTC_DCHECK_EQ(num_capture_channels_,
                 adaptive_filter_impulse_responses.size());

   // Analyze the filter outputs and filters.
   bool any_filter_converged;
   bool any_coarse_filter_converged;
   bool all_filters_diverged;
   subtractor_output_analyzer_.Update(subtractor_output, &any_filter_converged,
                                      &any_coarse_filter_converged,
                                      &all_filters_diverged);

   bool any_filter_consistent;
   float max_echo_path_gain;
   filter_analyzer_.Update(adaptive_filter_impulse_responses, render_buffer,
                           &any_filter_consistent, &max_echo_path_gain);

   // Estimate the direct path delay of the filter.
   if (config_.filter.use_linear_filter) {
     delay_state_.Update(filter_analyzer_.FilterDelaysBlocks(), external_delay,
                         strong_not_saturated_render_blocks_);
   }

   const Block& aligned_render_block =
       render_buffer.GetBlock(-delay_state_.MinDirectPathFilterDelay());

   // Update render counters.
   bool active_render = false;
   for (int ch = 0; ch < aligned_render_block.NumChannels(); ++ch) {
     const float render_energy =
         std::inner_product(aligned_render_block.begin(/*block=*/0, ch),
                            aligned_render_block.end(/*block=*/0, ch),
                            aligned_render_block.begin(/*block=*/0, ch), 0.f);
     if (render_energy > (config_.render_levels.active_render_limit *
                          config_.render_levels.active_render_limit) *
                             kFftLengthBy2) {
       active_render = true;
       break;
     }
   }
   blocks_with_active_render_ += active_render ? 1 : 0;
   strong_not_saturated_render_blocks_ +=
       active_render && !SaturatedCapture() ? 1 : 0;

   std::array<float, kFftLengthBy2Plus1> avg_render_spectrum_with_reverb;

   ComputeAvgRenderReverb(render_buffer.GetSpectrumBuffer(),
                          delay_state_.MinDirectPathFilterDelay(),
                          ReverbDecay(/*mild=*/false), &avg_render_reverb_,
                          avg_render_spectrum_with_reverb);

   if (config_.echo_audibility.use_stationarity_properties) {
     // Update the echo audibility evaluator.
     echo_audibility_.Update(render_buffer, avg_render_reverb_.reverb(),
                             delay_state_.MinDirectPathFilterDelay(),
                             delay_state_.ExternalDelayReported());
   }

   // Update the ERL and ERLE measures.
   if (initial_state_.TransitionTriggered()) {
     erle_estimator_.Reset(false);
   }

   erle_estimator_.Update(render_buffer, adaptive_filter_frequency_responses,
                          avg_render_spectrum_with_reverb, Y2, E2_refined,
                          subtractor_output_analyzer_.ConvergedFilters());

   erl_estimator_.Update(
       subtractor_output_analyzer_.ConvergedFilters(),
       render_buffer.Spectrum(delay_state_.MinDirectPathFilterDelay()), Y2);

   // Detect and flag echo saturation.
   if (config_.ep_strength.echo_can_saturate) {
     saturation_detector_.Update(aligned_render_block, SaturatedCapture(),
                                 UsableLinearEstimate(), subtractor_output,
                                 max_echo_path_gain);
   } else {
     RTC_DCHECK(!saturation_detector_.SaturatedEcho());
   }

   // Update the decision on whether to use the initial state parameter set.
   initial_state_.Update(active_render, SaturatedCapture());

   // Detect whether the transparent mode should be activated.
   if (transparent_state_) {
     transparent_state_->Update(
         delay_state_.MinDirectPathFilterDelay(), any_filter_consistent,
         any_filter_converged, any_coarse_filter_converged, all_filters_diverged,
         active_render, SaturatedCapture());
   }

   // Analyze the quality of the filter.
   filter_quality_state_.Update(active_render, TransparentModeActive(),
                                SaturatedCapture(), external_delay,
                                any_filter_converged);

   // Update the reverb estimate.
   const bool stationary_block =
       config_.echo_audibility.use_stationarity_properties &&
       echo_audibility_.IsBlockStationary();

   reverb_model_estimator_.Update(
       filter_analyzer_.GetAdjustedFilters(),
       adaptive_filter_frequency_responses,
       erle_estimator_.GetInstLinearQualityEstimates(),
       delay_state_.DirectPathFilterDelays(),
       filter_quality_state_.UsableLinearFilterOutputs(), stationary_block);

   erle_estimator_.Dump(data_dumper_);
   reverb_model_estimator_.Dump(data_dumper_.get());
   data_dumper_->DumpRaw("aec3_active_render", active_render);
   data_dumper_->DumpRaw("aec3_erl", Erl());
   data_dumper_->DumpRaw("aec3_erl_time_domain", ErlTimeDomain());
   data_dumper_->DumpRaw("aec3_erle", Erle(/*onset_compensated=*/false)[0]);
   data_dumper_->DumpRaw("aec3_erle_onset_compensated",
                         Erle(/*onset_compensated=*/true)[0]);
   data_dumper_->DumpRaw("aec3_usable_linear_estimate", UsableLinearEstimate());
   data_dumper_->DumpRaw("aec3_transparent_mode", TransparentModeActive());
   data_dumper_->DumpRaw("aec3_filter_delay",
                         filter_analyzer_.MinFilterDelayBlocks());

   data_dumper_->DumpRaw("aec3_any_filter_consistent", any_filter_consistent);
   data_dumper_->DumpRaw("aec3_initial_state",
                         initial_state_.InitialStateActive());
   data_dumper_->DumpRaw("aec3_capture_saturation", SaturatedCapture());
   data_dumper_->DumpRaw("aec3_echo_saturation", SaturatedEcho());
   data_dumper_->DumpRaw("aec3_any_filter_converged", any_filter_converged);
   data_dumper_->DumpRaw("aec3_any_coarse_filter_converged",
                         any_coarse_filter_converged);
   data_dumper_->DumpRaw("aec3_all_filters_diverged", all_filters_diverged);

   data_dumper_->DumpRaw("aec3_external_delay_avaliable",
                         external_delay ? 1 : 0);
   data_dumper_->DumpRaw("aec3_filter_tail_freq_resp_est",
                         GetReverbFrequencyResponse());
   data_dumper_->DumpRaw("aec3_subtractor_y2", subtractor_output[0].y2);
   data_dumper_->DumpRaw("aec3_subtractor_e2_coarse",
                         subtractor_output[0].e2_coarse);
   data_dumper_->DumpRaw("aec3_subtractor_e2_refined",
                         subtractor_output[0].e2_refined);
 }

 AecState::InitialState::InitialState(const EchoCanceller3Config& config)
     : conservative_initial_phase_(config.filter.conservative_initial_phase),
       initial_state_seconds_(config.filter.initial_state_seconds) {
   Reset();
 }
 void AecState::InitialState::InitialState::Reset() {
   initial_state_ = true;
   strong_not_saturated_render_blocks_ = 0;
 }
 void AecState::InitialState::InitialState::Update(bool active_render,
                                                   bool saturated_capture) {
   strong_not_saturated_render_blocks_ +=
       active_render && !saturated_capture ? 1 : 0;

   // Flag whether the initial state is still active.
   bool prev_initial_state = initial_state_;
   if (conservative_initial_phase_) {
     initial_state_ =
         strong_not_saturated_render_blocks_ < 5 * kNumBlocksPerSecond;
   } else {
     initial_state_ = strong_not_saturated_render_blocks_ <
                      initial_state_seconds_ * kNumBlocksPerSecond;
   }

   // Flag whether the transition from the initial state has started.
   transition_triggered_ = !initial_state_ && prev_initial_state;
 }

 AecState::FilterDelay::FilterDelay(const EchoCanceller3Config& config,
                                    size_t num_capture_channels)
     : delay_headroom_blocks_(config.delay.delay_headroom_samples / kBlockSize),
       filter_delays_blocks_(num_capture_channels, delay_headroom_blocks_),
       min_filter_delay_(delay_headroom_blocks_) {}

 void AecState::FilterDelay::Update(
     rtc::ArrayView<const int> analyzer_filter_delay_estimates_blocks,
     const std::optional<DelayEstimate>& external_delay,
     size_t blocks_with_proper_filter_adaptation) {
   // Update the delay based on the external delay.
   if (external_delay &&
       (!external_delay_ || external_delay_->delay != external_delay->delay)) {
     external_delay_ = external_delay;
     external_delay_reported_ = true;
   }

   // Override the estimated delay if it is not certain that the filter has had
   // time to converge.
   const bool delay_estimator_may_not_have_converged =
       blocks_with_proper_filter_adaptation < 2 * kNumBlocksPerSecond;
   if (delay_estimator_may_not_have_converged && external_delay_) {
     const int delay_guess = delay_headroom_blocks_;
     std::fill(filter_delays_blocks_.begin(), filter_delays_blocks_.end(),
               delay_guess);
   } else {
     RTC_DCHECK_EQ(filter_delays_blocks_.size(),
                   analyzer_filter_delay_estimates_blocks.size());
     std::copy(analyzer_filter_delay_estimates_blocks.begin(),
               analyzer_filter_delay_estimates_blocks.end(),
               filter_delays_blocks_.begin());
   }

   min_filter_delay_ = *std::min_element(filter_delays_blocks_.begin(),
                                         filter_delays_blocks_.end());
 }

 AecState::FilteringQualityAnalyzer::FilteringQualityAnalyzer(
     const EchoCanceller3Config& config,
     size_t num_capture_channels)
     : use_linear_filter_(config.filter.use_linear_filter),
       usable_linear_filter_estimates_(num_capture_channels, false) {}

 void AecState::FilteringQualityAnalyzer::Reset() {
   std::fill(usable_linear_filter_estimates_.begin(),
             usable_linear_filter_estimates_.end(), false);
   overall_usable_linear_estimates_ = false;
   filter_update_blocks_since_reset_ = 0;
 }

 void AecState::FilteringQualityAnalyzer::Update(
     bool active_render,
     bool transparent_mode,
     bool saturated_capture,
     const std::optional<DelayEstimate>& external_delay,
     bool any_filter_converged) {
   // Update blocks counter.
   const bool filter_update = active_render && !saturated_capture;
   filter_update_blocks_since_reset_ += filter_update ? 1 : 0;
   filter_update_blocks_since_start_ += filter_update ? 1 : 0;

   // Store convergence flag when observed.
   convergence_seen_ = convergence_seen_ || any_filter_converged;

   // Verify requirements for achieving a decent filter. The requirements for
   // filter adaptation at call startup are more restrictive than after an
   // in-call reset.
   const bool sufficient_data_to_converge_at_startup =
       filter_update_blocks_since_start_ > kNumBlocksPerSecond * 0.4f;
   const bool sufficient_data_to_converge_at_reset =
       sufficient_data_to_converge_at_startup &&
       filter_update_blocks_since_reset_ > kNumBlocksPerSecond * 0.2f;

   // The linear filter can only be used if it has had time to converge.
   overall_usable_linear_estimates_ = sufficient_data_to_converge_at_startup &&
                                      sufficient_data_to_converge_at_reset;

   // The linear filter can only be used if an external delay or convergence have
   // been identified
   overall_usable_linear_estimates_ =
       overall_usable_linear_estimates_ && (external_delay || convergence_seen_);

   // If transparent mode is on, deactivate usign the linear filter.
   overall_usable_linear_estimates_ =
       overall_usable_linear_estimates_ && !transparent_mode;

   if (use_linear_filter_) {
     std::fill(usable_linear_filter_estimates_.begin(),
               usable_linear_filter_estimates_.end(),
               overall_usable_linear_estimates_);
   }
 }

 void AecState::SaturationDetector::Update(
     const Block& x,
     bool saturated_capture,
     bool usable_linear_estimate,
     rtc::ArrayView<const SubtractorOutput> subtractor_output,
     float echo_path_gain) {
   saturated_echo_ = false;
   if (!saturated_capture) {
     return;
   }

   if (usable_linear_estimate) {
     constexpr float kSaturationThreshold = 20000.f;
     for (size_t ch = 0; ch < subtractor_output.size(); ++ch) {
       saturated_echo_ =
           saturated_echo_ ||
           (subtractor_output[ch].s_refined_max_abs > kSaturationThreshold ||
            subtractor_output[ch].s_coarse_max_abs > kSaturationThreshold);
     }
   } else {
     float max_sample = 0.f;
     for (int ch = 0; ch < x.NumChannels(); ++ch) {
       rtc::ArrayView<const float, kBlockSize> x_ch = x.View(/*band=*/0, ch);
       for (float sample : x_ch) {
         max_sample = std::max(max_sample, fabsf(sample));
       }
     }

     const float kMargin = 10.f;
     float peak_echo_amplitude = max_sample * echo_path_gain * kMargin;
     saturated_echo_ = saturated_echo_ || peak_echo_amplitude > 32000;
   }
 }

 }  // 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 "modules/audio_processing/aec3/aec_state.h"

	#include <math.h>

	#include <algorithm>
	#include <numeric>
	#include <optional>
	#include <vector>

	#include "api/array_view.h"
	#include "modules/audio_processing/aec3/aec3_common.h"
	#include "modules/audio_processing/logging/apm_data_dumper.h"
	#include "rtc_base/checks.h"
	#include "system_wrappers/include/field_trial.h"

	namespace webrtc {
	namespace {

	bool DeactivateInitialStateResetAtEchoPathChange() {
	return field_trial::IsEnabled(
	"WebRTC-Aec3DeactivateInitialStateResetKillSwitch");
	}

	bool FullResetAtEchoPathChange() {
	return !field_trial::IsEnabled("WebRTC-Aec3AecStateFullResetKillSwitch");
	}

	bool SubtractorAnalyzerResetAtEchoPathChange() {
	return !field_trial::IsEnabled(
	"WebRTC-Aec3AecStateSubtractorAnalyzerResetKillSwitch");
	}

	void ComputeAvgRenderReverb(
	const SpectrumBuffer& spectrum_buffer,
	int delay_blocks,
	float reverb_decay,
	ReverbModel* reverb_model,
	rtc::ArrayView<float, kFftLengthBy2Plus1> reverb_power_spectrum) {
	RTC_DCHECK(reverb_model);
	const size_t num_render_channels = spectrum_buffer.buffer[0].size();
	int idx_at_delay =
	spectrum_buffer.OffsetIndex(spectrum_buffer.read, delay_blocks);
	int idx_past = spectrum_buffer.IncIndex(idx_at_delay);

	std::array<float, kFftLengthBy2Plus1> X2_data;
	rtc::ArrayView<const float> X2;
	if (num_render_channels > 1) {
	auto average_channels =
	[](size_t num_render_channels,
	rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>>
	spectrum_band_0,
	rtc::ArrayView<float, kFftLengthBy2Plus1> render_power) {
	std::fill(render_power.begin(), render_power.end(), 0.f);
	for (size_t ch = 0; ch < num_render_channels; ++ch) {
	for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
	render_power[k] += spectrum_band_0[ch][k];
	}
	}
	const float normalizer = 1.f / num_render_channels;
	for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
	render_power[k] *= normalizer;
	}
	};
	average_channels(num_render_channels, spectrum_buffer.buffer[idx_past],
	X2_data);
	reverb_model->UpdateReverbNoFreqShaping(
	X2_data, /power_spectrum_scaling=/1.0f, reverb_decay);

	average_channels(num_render_channels, spectrum_buffer.buffer[idx_at_delay],
	X2_data);
	X2 = X2_data;
	} else {
	reverb_model->UpdateReverbNoFreqShaping(
	spectrum_buffer.buffer[idx_past][/channel=/0],
	/power_spectrum_scaling=/1.0f, reverb_decay);

	X2 = spectrum_buffer.buffer[idx_at_delay][/channel=/0];
	}

	rtc::ArrayView<const float, kFftLengthBy2Plus1> reverb_power =
	reverb_model->reverb();
	for (size_t k = 0; k < X2.size(); ++k) {
	reverb_power_spectrum[k] = X2[k] + reverb_power[k];
	}
	}

	} // namespace

	std::atomic<int> AecState::instance_count_(0);

	void AecState::GetResidualEchoScaling(
	rtc::ArrayView<float> residual_scaling) const {
	bool filter_has_had_time_to_converge;
	if (config_.filter.conservative_initial_phase) {
	filter_has_had_time_to_converge =
	strong_not_saturated_render_blocks_ >= 1.5f * kNumBlocksPerSecond;
	} else {
	filter_has_had_time_to_converge =
	strong_not_saturated_render_blocks_ >= 0.8f * kNumBlocksPerSecond;
	}
	echo_audibility_.GetResidualEchoScaling(filter_has_had_time_to_converge,
	residual_scaling);
	}

	AecState::AecState(const EchoCanceller3Config& config,
	size_t num_capture_channels)
	: data_dumper_(new ApmDataDumper(instance_count_.fetch_add(1) + 1)),
	config_(config),
	num_capture_channels_(num_capture_channels),
	deactivate_initial_state_reset_at_echo_path_change_(
	DeactivateInitialStateResetAtEchoPathChange()),
	full_reset_at_echo_path_change_(FullResetAtEchoPathChange()),
	subtractor_analyzer_reset_at_echo_path_change_(
	SubtractorAnalyzerResetAtEchoPathChange()),
	initial_state_(config_),
	delay_state_(config_, num_capture_channels_),
	transparent_state_(TransparentMode::Create(config_)),
	filter_quality_state_(config_, num_capture_channels_),
	erl_estimator_(2 * kNumBlocksPerSecond),
	erle_estimator_(2 * kNumBlocksPerSecond, config_, num_capture_channels_),
	filter_analyzer_(config_, num_capture_channels_),
	echo_audibility_(
	config_.echo_audibility.use_stationarity_properties_at_init),
	reverb_model_estimator_(config_, num_capture_channels_),
	subtractor_output_analyzer_(num_capture_channels_) {}

	AecState::~AecState() = default;

	void AecState::HandleEchoPathChange(
	const EchoPathVariability& echo_path_variability) {
	const auto full_reset = [&]() {
	filter_analyzer_.Reset();
	capture_signal_saturation_ = false;
	strong_not_saturated_render_blocks_ = 0;
	blocks_with_active_render_ = 0;
	if (!deactivate_initial_state_reset_at_echo_path_change_) {
	initial_state_.Reset();
	}
	if (transparent_state_) {
	transparent_state_->Reset();
	}
	erle_estimator_.Reset(true);
	erl_estimator_.Reset();
	filter_quality_state_.Reset();
	};

	// TODO(peah): Refine the reset scheme according to the type of gain and
	// delay adjustment.

	if (full_reset_at_echo_path_change_ &&
	echo_path_variability.delay_change !=
	EchoPathVariability::DelayAdjustment::kNone) {
	full_reset();
	} else if (echo_path_variability.gain_change) {
	erle_estimator_.Reset(false);
	}
	if (subtractor_analyzer_reset_at_echo_path_change_) {
	subtractor_output_analyzer_.HandleEchoPathChange();
	}
	}

	void AecState::Update(
	const std::optional<DelayEstimate>& external_delay,
	rtc::ArrayView<const std::vector<std::array<float, kFftLengthBy2Plus1>>>
	adaptive_filter_frequency_responses,
	rtc::ArrayView<const std::vector<float>> adaptive_filter_impulse_responses,
	const RenderBuffer& render_buffer,
	rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> E2_refined,
	rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Y2,
	rtc::ArrayView<const SubtractorOutput> subtractor_output) {
	RTC_DCHECK_EQ(num_capture_channels_, Y2.size());
	RTC_DCHECK_EQ(num_capture_channels_, subtractor_output.size());
	RTC_DCHECK_EQ(num_capture_channels_,
	adaptive_filter_frequency_responses.size());
	RTC_DCHECK_EQ(num_capture_channels_,
	adaptive_filter_impulse_responses.size());

	// Analyze the filter outputs and filters.
	bool any_filter_converged;
	bool any_coarse_filter_converged;
	bool all_filters_diverged;
	subtractor_output_analyzer_.Update(subtractor_output, &any_filter_converged,
	&any_coarse_filter_converged,
	&all_filters_diverged);

	bool any_filter_consistent;
	float max_echo_path_gain;
	filter_analyzer_.Update(adaptive_filter_impulse_responses, render_buffer,
	&any_filter_consistent, &max_echo_path_gain);

	// Estimate the direct path delay of the filter.
	if (config_.filter.use_linear_filter) {
	delay_state_.Update(filter_analyzer_.FilterDelaysBlocks(), external_delay,
	strong_not_saturated_render_blocks_);
	}

	const Block& aligned_render_block =
	render_buffer.GetBlock(-delay_state_.MinDirectPathFilterDelay());

	// Update render counters.
	bool active_render = false;
	for (int ch = 0; ch < aligned_render_block.NumChannels(); ++ch) {
	const float render_energy =
	std::inner_product(aligned_render_block.begin(/block=/0, ch),
	aligned_render_block.end(/block=/0, ch),
	aligned_render_block.begin(/block=/0, ch), 0.f);
	if (render_energy > (config_.render_levels.active_render_limit *
	config_.render_levels.active_render_limit) *
	kFftLengthBy2) {
	active_render = true;
	break;
	}
	}
	blocks_with_active_render_ += active_render ? 1 : 0;
	strong_not_saturated_render_blocks_ +=
	active_render && !SaturatedCapture() ? 1 : 0;

	std::array<float, kFftLengthBy2Plus1> avg_render_spectrum_with_reverb;

	ComputeAvgRenderReverb(render_buffer.GetSpectrumBuffer(),
	delay_state_.MinDirectPathFilterDelay(),
	ReverbDecay(/mild=/false), &avg_render_reverb_,
	avg_render_spectrum_with_reverb);

	if (config_.echo_audibility.use_stationarity_properties) {
	// Update the echo audibility evaluator.
	echo_audibility_.Update(render_buffer, avg_render_reverb_.reverb(),
	delay_state_.MinDirectPathFilterDelay(),
	delay_state_.ExternalDelayReported());
	}

	// Update the ERL and ERLE measures.
	if (initial_state_.TransitionTriggered()) {
	erle_estimator_.Reset(false);
	}

	erle_estimator_.Update(render_buffer, adaptive_filter_frequency_responses,
	avg_render_spectrum_with_reverb, Y2, E2_refined,
	subtractor_output_analyzer_.ConvergedFilters());

	erl_estimator_.Update(
	subtractor_output_analyzer_.ConvergedFilters(),
	render_buffer.Spectrum(delay_state_.MinDirectPathFilterDelay()), Y2);

	// Detect and flag echo saturation.
	if (config_.ep_strength.echo_can_saturate) {
	saturation_detector_.Update(aligned_render_block, SaturatedCapture(),
	UsableLinearEstimate(), subtractor_output,
	max_echo_path_gain);
	} else {
	RTC_DCHECK(!saturation_detector_.SaturatedEcho());
	}

	// Update the decision on whether to use the initial state parameter set.
	initial_state_.Update(active_render, SaturatedCapture());

	// Detect whether the transparent mode should be activated.
	if (transparent_state_) {
	transparent_state_->Update(
	delay_state_.MinDirectPathFilterDelay(), any_filter_consistent,
	any_filter_converged, any_coarse_filter_converged, all_filters_diverged,
	active_render, SaturatedCapture());
	}

	// Analyze the quality of the filter.
	filter_quality_state_.Update(active_render, TransparentModeActive(),
	SaturatedCapture(), external_delay,
	any_filter_converged);

	// Update the reverb estimate.
	const bool stationary_block =
	config_.echo_audibility.use_stationarity_properties &&
	echo_audibility_.IsBlockStationary();

	reverb_model_estimator_.Update(
	filter_analyzer_.GetAdjustedFilters(),
	adaptive_filter_frequency_responses,
	erle_estimator_.GetInstLinearQualityEstimates(),
	delay_state_.DirectPathFilterDelays(),
	filter_quality_state_.UsableLinearFilterOutputs(), stationary_block);

	erle_estimator_.Dump(data_dumper_);
	reverb_model_estimator_.Dump(data_dumper_.get());
	data_dumper_->DumpRaw("aec3_active_render", active_render);
	data_dumper_->DumpRaw("aec3_erl", Erl());
	data_dumper_->DumpRaw("aec3_erl_time_domain", ErlTimeDomain());
	data_dumper_->DumpRaw("aec3_erle", Erle(/onset_compensated=/false)[0]);
	data_dumper_->DumpRaw("aec3_erle_onset_compensated",
	Erle(/onset_compensated=/true)[0]);
	data_dumper_->DumpRaw("aec3_usable_linear_estimate", UsableLinearEstimate());
	data_dumper_->DumpRaw("aec3_transparent_mode", TransparentModeActive());
	data_dumper_->DumpRaw("aec3_filter_delay",
	filter_analyzer_.MinFilterDelayBlocks());

	data_dumper_->DumpRaw("aec3_any_filter_consistent", any_filter_consistent);
	data_dumper_->DumpRaw("aec3_initial_state",
	initial_state_.InitialStateActive());
	data_dumper_->DumpRaw("aec3_capture_saturation", SaturatedCapture());
	data_dumper_->DumpRaw("aec3_echo_saturation", SaturatedEcho());
	data_dumper_->DumpRaw("aec3_any_filter_converged", any_filter_converged);
	data_dumper_->DumpRaw("aec3_any_coarse_filter_converged",
	any_coarse_filter_converged);
	data_dumper_->DumpRaw("aec3_all_filters_diverged", all_filters_diverged);

	data_dumper_->DumpRaw("aec3_external_delay_avaliable",
	external_delay ? 1 : 0);
	data_dumper_->DumpRaw("aec3_filter_tail_freq_resp_est",
	GetReverbFrequencyResponse());
	data_dumper_->DumpRaw("aec3_subtractor_y2", subtractor_output[0].y2);
	data_dumper_->DumpRaw("aec3_subtractor_e2_coarse",
	subtractor_output[0].e2_coarse);
	data_dumper_->DumpRaw("aec3_subtractor_e2_refined",
	subtractor_output[0].e2_refined);
	}

	AecState::InitialState::InitialState(const EchoCanceller3Config& config)
	: conservative_initial_phase_(config.filter.conservative_initial_phase),
	initial_state_seconds_(config.filter.initial_state_seconds) {
	Reset();
	}
	void AecState::InitialState::InitialState::Reset() {
	initial_state_ = true;
	strong_not_saturated_render_blocks_ = 0;
	}
	void AecState::InitialState::InitialState::Update(bool active_render,
	bool saturated_capture) {
	strong_not_saturated_render_blocks_ +=
	active_render && !saturated_capture ? 1 : 0;

	// Flag whether the initial state is still active.
	bool prev_initial_state = initial_state_;
	if (conservative_initial_phase_) {
	initial_state_ =
	strong_not_saturated_render_blocks_ < 5 * kNumBlocksPerSecond;
	} else {
	initial_state_ = strong_not_saturated_render_blocks_ <
	initial_state_seconds_ * kNumBlocksPerSecond;
	}

	// Flag whether the transition from the initial state has started.
	transition_triggered_ = !initial_state_ && prev_initial_state;
	}

	AecState::FilterDelay::FilterDelay(const EchoCanceller3Config& config,
	size_t num_capture_channels)
	: delay_headroom_blocks_(config.delay.delay_headroom_samples / kBlockSize),
	filter_delays_blocks_(num_capture_channels, delay_headroom_blocks_),
	min_filter_delay_(delay_headroom_blocks_) {}

	void AecState::FilterDelay::Update(
	rtc::ArrayView<const int> analyzer_filter_delay_estimates_blocks,
	const std::optional<DelayEstimate>& external_delay,
	size_t blocks_with_proper_filter_adaptation) {
	// Update the delay based on the external delay.
	if (external_delay &&
	(!external_delay_ \|\| external_delay_->delay != external_delay->delay)) {
	external_delay_ = external_delay;
	external_delay_reported_ = true;
	}

	// Override the estimated delay if it is not certain that the filter has had
	// time to converge.
	const bool delay_estimator_may_not_have_converged =
	blocks_with_proper_filter_adaptation < 2 * kNumBlocksPerSecond;
	if (delay_estimator_may_not_have_converged && external_delay_) {
	const int delay_guess = delay_headroom_blocks_;
	std::fill(filter_delays_blocks_.begin(), filter_delays_blocks_.end(),
	delay_guess);
	} else {
	RTC_DCHECK_EQ(filter_delays_blocks_.size(),
	analyzer_filter_delay_estimates_blocks.size());
	std::copy(analyzer_filter_delay_estimates_blocks.begin(),
	analyzer_filter_delay_estimates_blocks.end(),
	filter_delays_blocks_.begin());
	}

	min_filter_delay_ = *std::min_element(filter_delays_blocks_.begin(),
	filter_delays_blocks_.end());
	}

	AecState::FilteringQualityAnalyzer::FilteringQualityAnalyzer(
	const EchoCanceller3Config& config,
	size_t num_capture_channels)
	: use_linear_filter_(config.filter.use_linear_filter),
	usable_linear_filter_estimates_(num_capture_channels, false) {}

	void AecState::FilteringQualityAnalyzer::Reset() {
	std::fill(usable_linear_filter_estimates_.begin(),
	usable_linear_filter_estimates_.end(), false);
	overall_usable_linear_estimates_ = false;
	filter_update_blocks_since_reset_ = 0;
	}

	void AecState::FilteringQualityAnalyzer::Update(
	bool active_render,
	bool transparent_mode,
	bool saturated_capture,
	const std::optional<DelayEstimate>& external_delay,
	bool any_filter_converged) {
	// Update blocks counter.
	const bool filter_update = active_render && !saturated_capture;
	filter_update_blocks_since_reset_ += filter_update ? 1 : 0;
	filter_update_blocks_since_start_ += filter_update ? 1 : 0;

	// Store convergence flag when observed.
	convergence_seen_ = convergence_seen_ \|\| any_filter_converged;

	// Verify requirements for achieving a decent filter. The requirements for
	// filter adaptation at call startup are more restrictive than after an
	// in-call reset.
	const bool sufficient_data_to_converge_at_startup =
	filter_update_blocks_since_start_ > kNumBlocksPerSecond * 0.4f;
	const bool sufficient_data_to_converge_at_reset =
	sufficient_data_to_converge_at_startup &&
	filter_update_blocks_since_reset_ > kNumBlocksPerSecond * 0.2f;

	// The linear filter can only be used if it has had time to converge.
	overall_usable_linear_estimates_ = sufficient_data_to_converge_at_startup &&
	sufficient_data_to_converge_at_reset;

	// The linear filter can only be used if an external delay or convergence have
	// been identified
	overall_usable_linear_estimates_ =
	overall_usable_linear_estimates_ && (external_delay \|\| convergence_seen_);

	// If transparent mode is on, deactivate usign the linear filter.
	overall_usable_linear_estimates_ =
	overall_usable_linear_estimates_ && !transparent_mode;

	if (use_linear_filter_) {
	std::fill(usable_linear_filter_estimates_.begin(),
	usable_linear_filter_estimates_.end(),
	overall_usable_linear_estimates_);
	}
	}

	void AecState::SaturationDetector::Update(
	const Block& x,
	bool saturated_capture,
	bool usable_linear_estimate,
	rtc::ArrayView<const SubtractorOutput> subtractor_output,
	float echo_path_gain) {
	saturated_echo_ = false;
	if (!saturated_capture) {
	return;
	}

	if (usable_linear_estimate) {
	constexpr float kSaturationThreshold = 20000.f;
	for (size_t ch = 0; ch < subtractor_output.size(); ++ch) {
	saturated_echo_ =
	saturated_echo_ \|\|
	(subtractor_output[ch].s_refined_max_abs > kSaturationThreshold \|\|
	subtractor_output[ch].s_coarse_max_abs > kSaturationThreshold);
	}
	} else {
	float max_sample = 0.f;
	for (int ch = 0; ch < x.NumChannels(); ++ch) {
	rtc::ArrayView<const float, kBlockSize> x_ch = x.View(/band=/0, ch);
	for (float sample : x_ch) {
	max_sample = std::max(max_sample, fabsf(sample));
	}
	}

	const float kMargin = 10.f;
	float peak_echo_amplitude = max_sample * echo_path_gain * kMargin;
	saturated_echo_ = saturated_echo_ \|\| peak_echo_amplitude > 32000;
	}
	}

	} // namespace webrtc