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0cbb58e046
This is a reland of 87a7b82520
Original change's description:
> Refactoring of the noise suppressor and adding true multichannel support
>
> This CL adds proper multichannel support to the noise suppressor.
> To accomplish that in a safe way, a full refactoring of the noise
> suppressor code has been done.
>
> Due to floating point precision, the changes made are not entirely
> bitexact. They are, however, very close to being bitexact.
>
> As a safety measure, the former noise suppressor code is preserved
> and a kill-switch is added to allow revering to the legacy noise
> suppressor in case issues arise.
>
> Bug: webrtc:10895, b/143344262
> Change-Id: I0b071011b23265ac12e6d4b3956499d122286657
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158407
> Commit-Queue: Per Åhgren <peah@webrtc.org>
> Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#29646}
Bug: webrtc:10895, b/143344262
Change-Id: I236f1e67bb0baa4e30908a4cf7a8a7bb55fbced3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158747
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29663}
88 lines
2.8 KiB
C++
88 lines
2.8 KiB
C++
/*
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* Copyright (c) 2019 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/ns/quantile_noise_estimator.h"
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#include <algorithm>
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#include "modules/audio_processing/ns/fast_math.h"
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namespace webrtc {
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QuantileNoiseEstimator::QuantileNoiseEstimator() {
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quantile_.fill(0.f);
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density_.fill(0.3f);
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log_quantile_.fill(8.f);
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constexpr float kOneBySimult = 1.f / kSimult;
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for (size_t i = 0; i < kSimult; ++i) {
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counter_[i] = floor(kLongStartupPhaseBlocks * (i + 1.f) * kOneBySimult);
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}
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}
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void QuantileNoiseEstimator::Estimate(
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rtc::ArrayView<const float, kFftSizeBy2Plus1> signal_spectrum,
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rtc::ArrayView<float, kFftSizeBy2Plus1> noise_spectrum) {
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std::array<float, kFftSizeBy2Plus1> log_spectrum;
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LogApproximation(signal_spectrum, log_spectrum);
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int quantile_index_to_return = -1;
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// Loop over simultaneous estimates.
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for (int s = 0, k = 0; s < kSimult;
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++s, k += static_cast<int>(kFftSizeBy2Plus1)) {
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const float one_by_counter_plus_1 = 1.f / (counter_[s] + 1.f);
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for (int i = 0, j = k; i < static_cast<int>(kFftSizeBy2Plus1); ++i, ++j) {
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// Update log quantile estimate.
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const float delta = density_[j] > 1.f ? 40.f / density_[j] : 40.f;
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const float multiplier = delta * one_by_counter_plus_1;
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if (log_spectrum[i] > log_quantile_[j]) {
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log_quantile_[j] += 0.25f * multiplier;
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} else {
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log_quantile_[j] -= 0.75f * multiplier;
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}
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// Update density estimate.
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constexpr float kWidth = 0.01f;
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constexpr float kOneByWidthPlus2 = 1.f / (2.f * kWidth);
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if (fabs(log_spectrum[i] - log_quantile_[j]) < kWidth) {
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density_[j] = (counter_[s] * density_[j] + kOneByWidthPlus2) *
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one_by_counter_plus_1;
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}
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}
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if (counter_[s] >= kLongStartupPhaseBlocks) {
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counter_[s] = 0;
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if (num_updates_ >= kLongStartupPhaseBlocks) {
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quantile_index_to_return = k;
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}
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}
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++counter_[s];
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}
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// Sequentially update the noise during startup.
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if (num_updates_ < kLongStartupPhaseBlocks) {
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// Use the last "s" to get noise during startup that differ from zero.
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quantile_index_to_return = kFftSizeBy2Plus1 * (kSimult - 1);
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++num_updates_;
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}
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if (quantile_index_to_return >= 0) {
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ExpApproximation(
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rtc::ArrayView<const float>(&log_quantile_[quantile_index_to_return],
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kFftSizeBy2Plus1),
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quantile_);
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}
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std::copy(quantile_.begin(), quantile_.end(), noise_spectrum.begin());
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}
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} // namespace webrtc
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