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52f8188f5d
This reverts commit 6f37ed78d9.
Reason for revert: <INSERT REASONING HERE>
Original change's description:
> Deprecate the adaptive level controller
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> Level control handled by default-on AGC.
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> Bug: none
> Change-Id: I405daeceece12c896d41156b649fcfd556726f77
> Reviewed-on: https://webrtc-review.googlesource.com/59682
> Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
> Reviewed-by: Alex Loiko <aleloi@webrtc.org>
> Commit-Queue: Sam Zackrisson <saza@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#22305}
TBR=solenberg@webrtc.org,saza@webrtc.org,aleloi@webrtc.org
Change-Id: Ic52f41fcbebfd2291a51b17ac788313e1ceef163
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: none
Reviewed-on: https://webrtc-review.googlesource.com/60240
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22308}
87 lines
3.1 KiB
C++
87 lines
3.1 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/gain_selector.h"
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#include <math.h>
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#include <algorithm>
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#include "modules/audio_processing/include/audio_processing.h"
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#include "modules/audio_processing/level_controller/level_controller_constants.h"
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#include "rtc_base/checks.h"
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namespace webrtc {
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GainSelector::GainSelector() {
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Initialize(AudioProcessing::kSampleRate48kHz);
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}
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void GainSelector::Initialize(int sample_rate_hz) {
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gain_ = 1.f;
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frame_length_ = rtc::CheckedDivExact(sample_rate_hz, 100);
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highly_nonstationary_signal_hold_counter_ = 0;
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}
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// Chooses the gain to apply by the level controller such that
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// 1) The level of the stationary noise does not exceed
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// a predefined threshold.
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// 2) The gain does not exceed the gain that has been found
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// to saturate the signal.
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// 3) The peak level achieves the target peak level.
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// 4) The gain is not below 1.
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// 4) The gain is 1 if the signal has been classified as stationary
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// for a long time.
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// 5) The gain is not above the maximum gain.
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float GainSelector::GetNewGain(float peak_level,
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float noise_energy,
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float saturating_gain,
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bool gain_jumpstart,
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SignalClassifier::SignalType signal_type) {
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RTC_DCHECK_LT(0.f, peak_level);
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if (signal_type == SignalClassifier::SignalType::kHighlyNonStationary ||
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gain_jumpstart) {
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highly_nonstationary_signal_hold_counter_ = 100;
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} else {
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highly_nonstationary_signal_hold_counter_ =
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std::max(0, highly_nonstationary_signal_hold_counter_ - 1);
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}
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float desired_gain;
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if (highly_nonstationary_signal_hold_counter_ > 0) {
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// Compute a desired gain that ensures that the peak level is amplified to
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// the target level.
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desired_gain = kTargetLcPeakLevel / peak_level;
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// Limit the desired gain so that it does not amplify the noise too much.
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float max_noise_energy = kMaxLcNoisePower * frame_length_;
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if (noise_energy * desired_gain * desired_gain > max_noise_energy) {
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RTC_DCHECK_LE(0.f, noise_energy);
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desired_gain = sqrtf(max_noise_energy / noise_energy);
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}
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} else {
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// If the signal has been stationary for a long while, apply a gain of 1 to
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// avoid amplifying pure noise.
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desired_gain = 1.0f;
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}
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// Smootly update the gain towards the desired gain.
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gain_ += 0.2f * (desired_gain - gain_);
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// Limit the gain to not exceed the maximum and the saturating gains, and to
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// ensure that the lowest possible gain is 1.
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gain_ = std::min(gain_, saturating_gain);
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gain_ = std::min(gain_, kMaxLcGain);
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gain_ = std::max(gain_, 1.f);
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return gain_;
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}
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} // namespace webrtc
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