Avoid AGC2 runtime allocation and activate it on demand

This CL ensures that the AGC2 is created and initialized only when
needed.

Apart from that, the CL also avoids a runtime-reallocation that happens
each time the setting is applied.

Bug: webrtc:5298
Change-Id: Iad9eaa05a3d0baa0788cd11b2aa17ddd8e0c509b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/163987
Commit-Queue: Per Åhgren <peah@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30139}

modules/audio_processing/audio_processing_impl.cc

@@ -372,10 +372,6 @@ AudioProcessingImpl::AudioProcessingImpl(
         new rtc::RefCountedObject<ResidualEchoDetector>();
   }
 
-  // TODO(alessiob): Move the injected gain controller once injection is
-  // implemented.
-  submodules_.gain_controller2.reset(new GainController2());
-
   // TODO(webrtc:5298): Remove once the use of ExperimentalNs has been
   // deprecated.
 #if !(defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS))
@@ -656,6 +652,9 @@ void AudioProcessingImpl::ApplyConfig(const AudioProcessing::Config& config) {
       config_.gain_controller1.analog_level_maximum !=
           config.gain_controller1.analog_level_maximum;
 
+  const bool agc2_config_changed =
+      config_.gain_controller2.enabled != config.gain_controller2.enabled;
+
   const bool voice_detection_config_changed =
       config_.voice_detection.enabled != config.voice_detection.enabled;
 
@@ -694,9 +693,10 @@ void AudioProcessingImpl::ApplyConfig(const AudioProcessing::Config& config) {
                       << "\nReverting to default parameter set";
     config_.gain_controller2 = AudioProcessing::Config::GainController2();
   }
+  if (agc2_config_changed) {
     InitializeGainController2();
+  }
   InitializePreAmplifier();
-  submodules_.gain_controller2->ApplyConfig(config_.gain_controller2);
 
   if (config_.level_estimation.enabled && !submodules_.output_level_estimator) {
     submodules_.output_level_estimator = std::make_unique<LevelEstimator>();
@@ -931,7 +931,7 @@ void AudioProcessingImpl::HandleCaptureRuntimeSettings() {
         break;
       }
       case RuntimeSetting::Type::kCaptureFixedPostGain: {
-        if (config_.gain_controller2.enabled) {
+        if (submodules_.gain_controller2) {
           float value;
           setting.GetFloat(&value);
           config_.gain_controller2.fixed_digital.gain_db = value;
@@ -1411,7 +1411,7 @@ int AudioProcessingImpl::ProcessCaptureStreamLocked() {
     submodules_.capture_analyzer->Analyze(capture_buffer);
   }
 
-  if (config_.gain_controller2.enabled) {
+  if (submodules_.gain_controller2) {
     submodules_.gain_controller2->NotifyAnalogLevel(
         recommended_stream_analog_level());
     submodules_.gain_controller2->Process(capture_buffer);
@@ -1761,7 +1761,7 @@ bool AudioProcessingImpl::UpdateActiveSubmoduleStates() {
       config_.high_pass_filter.enabled, !!submodules_.echo_control_mobile,
       config_.residual_echo_detector.enabled,
       !!submodules_.legacy_noise_suppressor || !!submodules_.noise_suppressor,
-      submodules_.gain_control->is_enabled(), config_.gain_controller2.enabled,
+      submodules_.gain_control->is_enabled(), !!submodules_.gain_controller2,
       config_.pre_amplifier.enabled, capture_nonlocked_.echo_controller_enabled,
       config_.voice_detection.enabled, !!submodules_.transient_suppressor);
 }
@@ -1888,7 +1888,16 @@ void AudioProcessingImpl::InitializeEchoController() {
 
 void AudioProcessingImpl::InitializeGainController2() {
   if (config_.gain_controller2.enabled) {
+    if (!submodules_.gain_controller2) {
+      // TODO(alessiob): Move the injected gain controller once injection is
+      // implemented.
+      submodules_.gain_controller2.reset(new GainController2());
+    }
+
     submodules_.gain_controller2->Initialize(proc_fullband_sample_rate_hz());
+    submodules_.gain_controller2->ApplyConfig(config_.gain_controller2);
+  } else {
+    submodules_.gain_controller2.reset();
   }
 }
 

modules/audio_processing/gain_controller2.cc

@@ -27,8 +27,11 @@ GainController2::GainController2()
           new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
       gain_applier_(/*hard_clip_samples=*/false,
                     /*initial_gain_factor=*/0.f),
-      adaptive_agc_(new AdaptiveAgc(data_dumper_.get())),
+      limiter_(static_cast<size_t>(48000), data_dumper_.get(), "Agc2") {
-      limiter_(static_cast<size_t>(48000), data_dumper_.get(), "Agc2") {}
+  if (config_.adaptive_digital.enabled) {
+    adaptive_agc_.reset(new AdaptiveAgc(data_dumper_.get()));
+  }
+}
 
 GainController2::~GainController2() = default;
 
@@ -47,14 +50,14 @@ void GainController2::Process(AudioBuffer* audio) {
                                     audio->num_frames());
   // Apply fixed gain first, then the adaptive one.
   gain_applier_.ApplyGain(float_frame);
-  if (config_.adaptive_digital.enabled) {
+  if (adaptive_agc_) {
     adaptive_agc_->Process(float_frame, limiter_.LastAudioLevel());
   }
   limiter_.Process(float_frame);
 }
 
 void GainController2::NotifyAnalogLevel(int level) {
-  if (analog_level_ != level && config_.adaptive_digital.enabled) {
+  if (analog_level_ != level && adaptive_agc_) {
     adaptive_agc_->Reset();
   }
   analog_level_ = level;
@@ -72,7 +75,11 @@ void GainController2::ApplyConfig(
     limiter_.Reset();
   }
   gain_applier_.SetGainFactor(DbToRatio(config_.fixed_digital.gain_db));
+  if (config_.adaptive_digital.enabled) {
     adaptive_agc_.reset(new AdaptiveAgc(data_dumper_.get(), config_));
+  } else {
+    adaptive_agc_.reset();
+  }
 }
 
 bool GainController2::Validate(