commit e583174d1ed9ec00ab0e1b3ebb5989ef6aae4223
author Alex Loiko <aleloi@webrtc.org> Fri Aug 24 11:28:36 2018 +0200
committer Commit Bot <commit-bot@chromium.org> Fri Aug 24 15:54:43 2018 +0000
tree cace829ef94c66e824fe0982196632c126b383a5
parent 5c2de6b3ce079cff52c411a2c02ce6553a38dc79

Optionally disable digital adaptive AGC2.

The AGC2 is enabled by flipping
AudioProcessing::Config::GainController2::enabled. The flag enables
both AdaptiveAgc and FixedGainController. Before this CL, there was no
way(*) to only enable the FixedGainController. After this CL, it's
also possible to flip the setting
|AudioProcessing::Config::GainController2::adaptive_digital_mode|. The
default is |true|, which is the previous behavior.

* Except for instantiating and setting it up outside of the APM like
  it's done in the AudioMixer.

Bug: webrtc:7494
Change-Id: I506e93b6687221ac467f083fa8db3d45c98c1b83
Reviewed-on: https://webrtc-review.googlesource.com/95426
Commit-Queue: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24432}

modules/audio_processing/gain_controller2.cc

diff --git a/modules/audio_processing/gain_controller2.cc b/modules/audio_processing/gain_controller2.cc
index cdfcffa..fd4b411 100644
--- a/modules/audio_processing/gain_controller2.cc
+++ b/modules/audio_processing/gain_controller2.cc
@@ -41,12 +41,14 @@
 void GainController2::Process(AudioBuffer* audio) {
   AudioFrameView<float> float_frame(audio->channels_f(), audio->num_channels(),
                                     audio->num_frames());
-  adaptive_agc_.Process(float_frame);
+  if (adaptive_digital_mode_) {
+    adaptive_agc_.Process(float_frame);
+  }
   fixed_gain_controller_.Process(float_frame);
 }
 
 void GainController2::NotifyAnalogLevel(int level) {
-  if (analog_level_ != level) {
+  if (analog_level_ != level && adaptive_digital_mode_) {
     adaptive_agc_.Reset();
   }
   analog_level_ = level;
@@ -57,6 +59,7 @@
   RTC_DCHECK(Validate(config));
   config_ = config;
   fixed_gain_controller_.SetGain(config_.fixed_gain_db);
+  adaptive_digital_mode_ = config_.adaptive_digital_mode;
 }
 
 bool GainController2::Validate(

modules/audio_processing/gain_controller2.h

diff --git a/modules/audio_processing/gain_controller2.h b/modules/audio_processing/gain_controller2.h
index 41b7b69..b4727d0 100644
--- a/modules/audio_processing/gain_controller2.h
+++ b/modules/audio_processing/gain_controller2.h
@@ -47,6 +47,7 @@
   AudioProcessing::Config::GainController2 config_;
   AdaptiveAgc adaptive_agc_;
   int analog_level_ = -1;
+  bool adaptive_digital_mode_ = true;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(GainController2);
 };

modules/audio_processing/include/audio_processing.h

diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 9c750f0..22fa92d 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -273,12 +273,15 @@
       float fixed_gain_factor = 1.f;
     } pre_amplifier;
 
-    // Enables the next generation AGC functionality. This feature
-    // replaces the standard methods of gain control in the previous
-    // AGC. This functionality is currently only partially
-    // implemented.
+    // Enables the next generation AGC functionality. This feature replaces the
+    // standard methods of gain control in the previous AGC. Enabling this
+    // submodule enables an adaptive digital AGC followed by a limiter. By
+    // setting |fixed_gain_db|, the limiter can be turned into a compressor that
+    // first applies a fixed gain. The adaptive digital AGC can be turned off by
+    // setting |adaptive_digital_mode=false|.
     struct GainController2 {
       bool enabled = false;
+      bool adaptive_digital_mode = true;
       float fixed_gain_db = 0.f;
     } gain_controller2;