Added functionality for specifying the initial signal level to use for the gain estimation in the l…

webrtc/modules/audio_processing/level_controller/gain_selector.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.
  */
 
@@ skipping 24 matching lines @@
 // 2) The gain does not exceed the gain that has been found
 //    to saturate the signal.
 // 3) The peak level achieves the target peak level.
 // 4) The gain is not below 1.
 // 4) The gain is 1 if the signal has been classified as stationary
 //    for a long time.
 // 5) The gain is not above the maximum gain.
 float GainSelector::GetNewGain(float peak_level,
                                float noise_energy,
                                float saturating_gain,
+                               bool jump_start_gain,
                                SignalClassifier::SignalType signal_type) {
   RTC_DCHECK_LT(0.f, peak_level);
 
-  if (signal_type == SignalClassifier::SignalType::kHighlyNonStationary) {
+  if (signal_type == SignalClassifier::SignalType::kHighlyNonStationary ||
+      jump_start_gain) {

[aleloi, 2016/08/18 11:43:39]

Is this to avoid having to wait for 100 iterations until a gain is applied?

[peah-webrtc, 2016/08/18 12:48:37]

Yes, that is correct.

     highly_nonstationary_signal_hold_counter_ = 100;
   } else {
     highly_nonstationary_signal_hold_counter_ =
         std::max(0, highly_nonstationary_signal_hold_counter_ - 1);
   }
 
   float desired_gain;
   if (highly_nonstationary_signal_hold_counter_ > 0) {
     // Compute a desired gain that ensures that the peak level is amplified to
     // the target level.
@@ skipping 17 matching lines @@
   // Limit the gain to not exceed the maximum and the saturating gains, and to
   // ensure that the lowest possible gain is 1.
   gain_ = std::min(gain_, saturating_gain);
   gain_ = std::min(gain_, kMaxLcGain);
   gain_ = std::max(gain_, 1.f);
 
   return gain_;
 }
 
 }  // namespace webrtc