Improved tuning of the adaptive level controller.

webrtc/modules/audio_processing/level_controller/saturating_gain_estimator.cc

 /*
  *  Copyright (c) 2016 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 "webrtc/modules/audio_processing/level_controller/saturating_gain_estimator.h"
 
 #include <math.h>
 #include <algorithm>
 
 #include "webrtc/modules/audio_processing/level_controller/lc_constants.h"
 #include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
 
 namespace webrtc {
 
 SaturatingGainEstimator::SaturatingGainEstimator() {
   Initialize();
 }
 
 SaturatingGainEstimator::~SaturatingGainEstimator() {}
 
 void SaturatingGainEstimator::Initialize() {
-  saturating_gain_ = 1000.f;
+  saturating_gain_ = kMaxLcGain;
   saturating_gain_hold_counter_ = 0;
 }
 
 void SaturatingGainEstimator::Update(float gain, int num_saturations) {
   bool too_many_saturations = (num_saturations > 2);
 
   if (too_many_saturations) {
     saturating_gain_ = 0.95f * gain;
     saturating_gain_hold_counter_ = 1000;
   } else {
     saturating_gain_hold_counter_ =
         std::max(0, saturating_gain_hold_counter_ - 1);
     if (saturating_gain_hold_counter_ == 0) {
       saturating_gain_ *= 1.001f;
       saturating_gain_ = std::min(kMaxLcGain, saturating_gain_);
     }
   }
 }
 
 }  // namespace webrtc