ebe7778ce9
and handling of echo path changes. This CL add tuning for the AEC3 that 1) Improves the handling of the initial echo suppression before the linear filter is reliable. 2) Improves the handling of echo path changes. There are also minor bugfixes included. BUG=webrtc:6018 Review-Url: https://codereview.webrtc.org/2717353002 Cr-Commit-Position: refs/heads/master@{#16873}
112 lines
3.5 KiB
C++
112 lines
3.5 KiB
C++
/*
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* Copyright (c) 2017 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 "webrtc/modules/audio_processing/aec3/power_echo_model.h"
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#include <string.h>
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#include <algorithm>
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#include "webrtc/base/optional.h"
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namespace webrtc {
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namespace {
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// Computes the spectral power over that last 20 frames.
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void RecentMaximum(const FftBuffer& X_buffer,
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std::array<float, kFftLengthBy2Plus1>* R2) {
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R2->fill(0.f);
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for (size_t j = 0; j < 20; ++j) {
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std::transform(R2->begin(), R2->end(), X_buffer.Spectrum(j).begin(),
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R2->begin(),
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[](float a, float b) { return std::max(a, b); });
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}
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}
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constexpr float kHInitial = 100.f;
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constexpr int kUpdateCounterInitial = 300;
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} // namespace
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PowerEchoModel::PowerEchoModel() {
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H2_.fill(CountedFloat(kHInitial, kUpdateCounterInitial));
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}
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PowerEchoModel::~PowerEchoModel() = default;
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void PowerEchoModel::HandleEchoPathChange(
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const EchoPathVariability& variability) {
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if (variability.gain_change) {
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H2_.fill(CountedFloat(kHInitial, kUpdateCounterInitial));
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}
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}
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void PowerEchoModel::EstimateEcho(
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const FftBuffer& render_buffer,
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const std::array<float, kFftLengthBy2Plus1>& capture_spectrum,
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const AecState& aec_state,
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std::array<float, kFftLengthBy2Plus1>* echo_spectrum) {
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RTC_DCHECK(echo_spectrum);
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const FftBuffer& X_buffer = render_buffer;
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const auto& Y2 = capture_spectrum;
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std::array<float, kFftLengthBy2Plus1>* S2 = echo_spectrum;
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// Choose delay to use.
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const rtc::Optional<size_t> delay =
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aec_state.FilterDelay()
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? aec_state.FilterDelay()
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: (aec_state.ExternalDelay() ? rtc::Optional<size_t>(std::min<size_t>(
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*aec_state.ExternalDelay(),
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X_buffer.Buffer().size() - 1))
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: rtc::Optional<size_t>());
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// Compute R2.
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std::array<float, kFftLengthBy2Plus1> render_max;
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if (!delay) {
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RecentMaximum(render_buffer, &render_max);
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}
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const std::array<float, kFftLengthBy2Plus1>& X2_active =
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delay ? render_buffer.Spectrum(*delay) : render_max;
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if (!aec_state.SaturatedCapture()) {
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// Corresponds of WGN of power -46dBFS.
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constexpr float kX2Min = 44015068.0f;
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const int max_update_counter_value = delay ? 300 : 500;
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std::array<float, kFftLengthBy2Plus1> new_H2;
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// new_H2 = Y2 / X2.
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std::transform(X2_active.begin(), X2_active.end(), Y2.begin(),
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new_H2.begin(),
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[&](float a, float b) { return a > kX2Min ? b / a : -1.f; });
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// Lambda for updating H2 in a maximum statistics manner.
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auto H2_updater = [&](float a, CountedFloat b) {
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if (a > 0) {
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if (a > b.value) {
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b.counter = max_update_counter_value;
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b.value = a;
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} else if (--b.counter <= 0) {
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b.value = std::max(b.value * 0.9f, 1.f);
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}
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}
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return b;
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};
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std::transform(new_H2.begin(), new_H2.end(), H2_.begin(), H2_.begin(),
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H2_updater);
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}
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// S2 = H2*X2_active.
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std::transform(H2_.begin(), H2_.end(), X2_active.begin(), S2->begin(),
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[](CountedFloat a, float b) { return a.value * b; });
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}
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} // namespace webrtc
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