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92ea95e34a
In https://webrtc-review.googlesource.com/c/src/+/1560 we moved WebRTC from src/webrtc to src/ (in order to preserve an healthy git history). This CL takes care of fixing header guards, #include paths, etc... NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true TBR=tommi@webrtc.org Bug: chromium:611808 Change-Id: Iea91618212bee0af16aa3f05071eab8f93706578 Reviewed-on: https://webrtc-review.googlesource.com/1561 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Henrik Kjellander <kjellander@webrtc.org> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#19846}
72 lines
2.4 KiB
C++
72 lines
2.4 KiB
C++
/*
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* Copyright (c) 2016 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/level_controller/noise_level_estimator.h"
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#include <algorithm>
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#include "modules/audio_processing/audio_buffer.h"
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#include "modules/audio_processing/logging/apm_data_dumper.h"
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namespace webrtc {
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NoiseLevelEstimator::NoiseLevelEstimator() {
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Initialize(AudioProcessing::kSampleRate48kHz);
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}
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NoiseLevelEstimator::~NoiseLevelEstimator() {}
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void NoiseLevelEstimator::Initialize(int sample_rate_hz) {
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noise_energy_ = 1.f;
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first_update_ = true;
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min_noise_energy_ = sample_rate_hz * 2.f * 2.f / 100.f;
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noise_energy_hold_counter_ = 0;
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}
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float NoiseLevelEstimator::Analyze(SignalClassifier::SignalType signal_type,
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float frame_energy) {
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if (frame_energy <= 0.f) {
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return noise_energy_;
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}
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if (first_update_) {
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// Initialize the noise energy to the frame energy.
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first_update_ = false;
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return noise_energy_ = std::max(frame_energy, min_noise_energy_);
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}
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// Update the noise estimate in a minimum statistics-type manner.
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if (signal_type == SignalClassifier::SignalType::kStationary) {
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if (frame_energy > noise_energy_) {
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// Leak the estimate upwards towards the frame energy if no recent
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// downward update.
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noise_energy_hold_counter_ = std::max(noise_energy_hold_counter_ - 1, 0);
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if (noise_energy_hold_counter_ == 0) {
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noise_energy_ = std::min(noise_energy_ * 1.01f, frame_energy);
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}
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} else {
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// Update smoothly downwards with a limited maximum update magnitude.
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noise_energy_ =
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std::max(noise_energy_ * 0.9f,
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noise_energy_ + 0.05f * (frame_energy - noise_energy_));
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noise_energy_hold_counter_ = 1000;
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}
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} else {
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// For a non-stationary signal, leak the estimate downwards in order to
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// avoid estimate locking due to incorrect signal classification.
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noise_energy_ = noise_energy_ * 0.99f;
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}
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// Ensure a minimum of the estimate.
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return noise_energy_ = std::max(noise_energy_, min_noise_energy_);
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}
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} // namespace webrtc
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