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/*
* 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_model_estimator.h"
#include <algorithm>
#include <array>
#include <cmath>
#include <numeric>
#include <vector>
#include "absl/types/optional.h"
#include "api/array_view.h"
#include "api/audio/echo_canceller3_config.h"
#include "modules/audio_processing/aec3/aec3_common.h"
#include "modules/audio_processing/aec3/aec3_fft.h"
#include "modules/audio_processing/aec3/fft_data.h"
#include "rtc_base/checks.h"
#include "test/gtest.h"
namespace webrtc {
namespace {
EchoCanceller3Config CreateConfigForTest(float default_decay) {
EchoCanceller3Config cfg;
cfg.ep_strength.default_len = default_decay;
cfg.filter.refined.length_blocks = 40;
return cfg;
}
constexpr int kFilterDelayBlocks = 2;
} // namespace
class ReverbModelEstimatorTest {
public:
ReverbModelEstimatorTest(float default_decay, size_t num_capture_channels)
: aec3_config_(CreateConfigForTest(default_decay)),
estimated_decay_(default_decay),
h_(num_capture_channels,
std::vector<float>(
aec3_config_.filter.refined.length_blocks * kBlockSize,
0.f)),
H2_(num_capture_channels,
std::vector<std::array<float, kFftLengthBy2Plus1>>(
aec3_config_.filter.refined.length_blocks)),
quality_linear_(num_capture_channels, 1.0f) {
CreateImpulseResponseWithDecay();
}
void RunEstimator();
float GetDecay(bool mild) {
return mild ? mild_estimated_decay_ : estimated_decay_;
}
float GetTrueDecay() { return kTruePowerDecay; }
float GetPowerTailDb() { return 10.f * std::log10(estimated_power_tail_); }
float GetTruePowerTailDb() { return 10.f * std::log10(true_power_tail_); }
private:
void CreateImpulseResponseWithDecay();
static constexpr bool kStationaryBlock = false;
static constexpr float kTruePowerDecay = 0.5f;
const EchoCanceller3Config aec3_config_;
float estimated_decay_;
float mild_estimated_decay_;
float estimated_power_tail_ = 0.f;
float true_power_tail_ = 0.f;
std::vector<std::vector<float>> h_;
std::vector<std::vector<std::array<float, kFftLengthBy2Plus1>>> H2_;
std::vector<absl::optional<float>> quality_linear_;
};
void ReverbModelEstimatorTest::CreateImpulseResponseWithDecay() {
const Aec3Fft fft;
for (const auto& h_k : h_) {
RTC_DCHECK_EQ(h_k.size(),
aec3_config_.filter.refined.length_blocks * kBlockSize);
}
for (const auto& H2_k : H2_) {
RTC_DCHECK_EQ(H2_k.size(), aec3_config_.filter.refined.length_blocks);
}
RTC_DCHECK_EQ(kFilterDelayBlocks, 2);
float decay_sample = std::sqrt(powf(kTruePowerDecay, 1.f / kBlockSize));
const size_t filter_delay_coefficients = kFilterDelayBlocks * kBlockSize;
for (auto& h_i : h_) {
std::fill(h_i.begin(), h_i.end(), 0.f);
h_i[filter_delay_coefficients] = 1.f;
for (size_t k = filter_delay_coefficients + 1; k < h_i.size(); ++k) {
h_i[k] = h_i[k - 1] * decay_sample;
}
}
for (size_t ch = 0; ch < H2_.size(); ++ch) {
for (size_t j = 0, k = 0; j < H2_[ch].size(); ++j, k += kBlockSize) {
std::array<float, kFftLength> fft_data;
fft_data.fill(0.f);
std::copy(h_[ch].begin() + k, h_[ch].begin() + k + kBlockSize,
fft_data.begin());
FftData H_j;
fft.Fft(&fft_data, &H_j);
H_j.Spectrum(Aec3Optimization::kNone, H2_[ch][j]);
}
}
rtc::ArrayView<float> H2_tail(H2_[0][H2_[0].size() - 1]);
true_power_tail_ = std::accumulate(H2_tail.begin(), H2_tail.end(), 0.f);
}
void ReverbModelEstimatorTest::RunEstimator() {
const size_t num_capture_channels = H2_.size();
constexpr bool kUsableLinearEstimate = true;
ReverbModelEstimator estimator(aec3_config_, num_capture_channels);
std::vector<bool> usable_linear_estimates(num_capture_channels,
kUsableLinearEstimate);
std::vector<int> filter_delay_blocks(num_capture_channels,
kFilterDelayBlocks);
for (size_t k = 0; k < 3000; ++k) {
estimator.Update(h_, H2_, quality_linear_, filter_delay_blocks,
usable_linear_estimates, kStationaryBlock);
}
estimated_decay_ = estimator.ReverbDecay(/*mild=*/false);
mild_estimated_decay_ = estimator.ReverbDecay(/*mild=*/true);
auto freq_resp_tail = estimator.GetReverbFrequencyResponse();
estimated_power_tail_ =
std::accumulate(freq_resp_tail.begin(), freq_resp_tail.end(), 0.f);
}
TEST(ReverbModelEstimatorTests, NotChangingDecay) {
constexpr float kDefaultDecay = 0.9f;
for (size_t num_capture_channels : {1, 2, 4, 8}) {
ReverbModelEstimatorTest test(kDefaultDecay, num_capture_channels);
test.RunEstimator();
EXPECT_EQ(test.GetDecay(/*mild=*/false), kDefaultDecay);
EXPECT_EQ(test.GetDecay(/*mild=*/true),
EchoCanceller3Config().ep_strength.nearend_len);
EXPECT_NEAR(test.GetPowerTailDb(), test.GetTruePowerTailDb(), 5.f);
}
}
TEST(ReverbModelEstimatorTests, ChangingDecay) {
constexpr float kDefaultDecay = -0.9f;
for (size_t num_capture_channels : {1, 2, 4, 8}) {
ReverbModelEstimatorTest test(kDefaultDecay, num_capture_channels);
test.RunEstimator();
EXPECT_NEAR(test.GetDecay(/*mild=*/false), test.GetTrueDecay(), 0.1f);
EXPECT_NEAR(test.GetDecay(/*mild=*/true), test.GetTrueDecay(), 0.1f);
EXPECT_NEAR(test.GetPowerTailDb(), test.GetTruePowerTailDb(), 5.f);
}
}
} // namespace webrtc