chromium/third_party/webrtc/modules/audio_processing/aec3/residual_echo_estimator.cc

/*
 *  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/residual_echo_estimator.h"

#include <stddef.h>

#include <algorithm>
#include <vector>

#include "api/array_view.h"
#include "modules/audio_processing/aec3/reverb_model.h"
#include "rtc_base/checks.h"
#include "system_wrappers/include/field_trial.h"

namespace webrtc {
namespace {

constexpr float kDefaultTransparentModeGain = …;

float GetTransparentModeGain() { … }

float GetEarlyReflectionsDefaultModeGain(
    const EchoCanceller3Config::EpStrength& config) { … }

float GetLateReflectionsDefaultModeGain(
    const EchoCanceller3Config::EpStrength& config) { … }

bool UseErleOnsetCompensationInDominantNearend(
    const EchoCanceller3Config::EpStrength& config) { … }

// Computes the indexes that will be used for computing spectral power over
// the blocks surrounding the delay.
void GetRenderIndexesToAnalyze(
    const SpectrumBuffer& spectrum_buffer,
    const EchoCanceller3Config::EchoModel& echo_model,
    int filter_delay_blocks,
    int* idx_start,
    int* idx_stop) { … }

// Estimates the residual echo power based on the echo return loss enhancement
// (ERLE) and the linear power estimate.
void LinearEstimate(
    rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> S2_linear,
    rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> erle,
    rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> R2) { … }

// Estimates the residual echo power based on the estimate of the echo path
// gain.
void NonLinearEstimate(
    float echo_path_gain,
    const std::array<float, kFftLengthBy2Plus1>& X2,
    rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> R2) { … }

// Applies a soft noise gate to the echo generating power.
void ApplyNoiseGate(const EchoCanceller3Config::EchoModel& config,
                    rtc::ArrayView<float, kFftLengthBy2Plus1> X2) { … }

// Estimates the echo generating signal power as gated maximal power over a
// time window.
void EchoGeneratingPower(size_t num_render_channels,
                         const SpectrumBuffer& spectrum_buffer,
                         const EchoCanceller3Config::EchoModel& echo_model,
                         int filter_delay_blocks,
                         rtc::ArrayView<float, kFftLengthBy2Plus1> X2) { … }

}  // namespace

ResidualEchoEstimator::ResidualEchoEstimator(const EchoCanceller3Config& config,
                                             size_t num_render_channels)
    : … { … }

ResidualEchoEstimator::~ResidualEchoEstimator() = default;

void ResidualEchoEstimator::Estimate(
    const AecState& aec_state,
    const RenderBuffer& render_buffer,
    rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> S2_linear,
    rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>> Y2,
    bool dominant_nearend,
    rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> R2,
    rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> R2_unbounded) { … }

void ResidualEchoEstimator::Reset() { … }

void ResidualEchoEstimator::UpdateRenderNoisePower(
    const RenderBuffer& render_buffer) { … }

// Updates the reverb estimation.
void ResidualEchoEstimator::UpdateReverb(ReverbType reverb_type,
                                         const AecState& aec_state,
                                         const RenderBuffer& render_buffer,
                                         bool dominant_nearend) { … }
// Adds the estimated power of the reverb to the residual echo power.
void ResidualEchoEstimator::AddReverb(
    rtc::ArrayView<std::array<float, kFftLengthBy2Plus1>> R2) const { … }

// Chooses the echo path gain to use.
float ResidualEchoEstimator::GetEchoPathGain(
    const AecState& aec_state,
    bool gain_for_early_reflections) const { … }

}  // namespace webrtc