reverb_decay_estimator.cc | Explore in Territory

/*
 *  Copyright (c) 2018 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/reverb_decay_estimator.h"

#include <stddef.h>

#include <algorithm>
#include <cmath>
#include <numeric>

#include "api/array_view.h"
#include "api/audio/echo_canceller3_config.h"
#include "modules/audio_processing/logging/apm_data_dumper.h"
#include "rtc_base/checks.h"

namespace webrtc {

namespace {

constexpr int kEarlyReverbMinSizeBlocks = …;
constexpr int kBlocksPerSection = …;
// Linear regression approach assumes symmetric index around 0.
constexpr float kEarlyReverbFirstPointAtLinearRegressors = …;

// Averages the values in a block of size kFftLengthBy2;
float BlockAverage(rtc::ArrayView<const float> v, size_t block_index) { … }

// Analyzes the gain in a block.
void AnalyzeBlockGain(const std::array<float, kFftLengthBy2>& h2,
                      float floor_gain,
                      float* previous_gain,
                      bool* block_adapting,
                      bool* decaying_gain) { … }

// Arithmetic sum of $2 \sum_{i=0.5}^{(N-1)/2}i^2$ calculated directly.
constexpr float SymmetricArithmetricSum(int N) { … }

// Returns the peak energy of an impulse response.
float BlockEnergyPeak(rtc::ArrayView<const float> h, int peak_block) { … }

// Returns the average energy of an impulse response block.
float BlockEnergyAverage(rtc::ArrayView<const float> h, int block_index) { … }

}  // namespace

ReverbDecayEstimator::ReverbDecayEstimator(const EchoCanceller3Config& config)
    : … { … }

ReverbDecayEstimator::~ReverbDecayEstimator() = default;

void ReverbDecayEstimator::Update(rtc::ArrayView<const float> filter,
                                  const absl::optional<float>& filter_quality,
                                  int filter_delay_blocks,
                                  bool usable_linear_filter,
                                  bool stationary_signal) { … }

void ReverbDecayEstimator::ResetDecayEstimation() { … }

void ReverbDecayEstimator::EstimateDecay(rtc::ArrayView<const float> filter,
                                         int peak_block) { … }

void ReverbDecayEstimator::AnalyzeFilter(rtc::ArrayView<const float> filter) { … }

void ReverbDecayEstimator::Dump(ApmDataDumper* data_dumper) const { … }

void ReverbDecayEstimator::LateReverbLinearRegressor::Reset(
    int num_data_points) { … }

void ReverbDecayEstimator::LateReverbLinearRegressor::Accumulate(float z) { … }

float ReverbDecayEstimator::LateReverbLinearRegressor::Estimate() { … }

ReverbDecayEstimator::EarlyReverbLengthEstimator::EarlyReverbLengthEstimator(
    int max_blocks)
    : … { … }

ReverbDecayEstimator::EarlyReverbLengthEstimator::
    ~EarlyReverbLengthEstimator() = default;

void ReverbDecayEstimator::EarlyReverbLengthEstimator::Reset() { … }

void ReverbDecayEstimator::EarlyReverbLengthEstimator::Accumulate(
    float value,
    float smoothing) { … }

// Estimates the size in blocks of the early reverb. The estimation is done by
// comparing the tilt that is estimated in each section. As an optimization
// detail and due to the fact that all the linear regressors that are computed
// shared the same denominator, the comparison of the tilts is done by a
// comparison of the numerator of the linear regressors.
int ReverbDecayEstimator::EarlyReverbLengthEstimator::Estimate() { … }

void ReverbDecayEstimator::EarlyReverbLengthEstimator::Dump(
    ApmDataDumper* data_dumper) const { … }

}  // namespace webrtc
chromium/third_party/webrtc/modules/audio_processing/aec3/reverb_decay_estimator.cc
