Add empty residual echo detector.

webrtc/modules/audio_processing/audio_processing_impl.cc

Index: webrtc/modules/audio_processing/audio_processing_impl.cc
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.cc b/webrtc/modules/audio_processing/audio_processing_impl.cc
index 85f159716cf9d49753fad1fdd18108971b922a9b..6db2c057167f4a896ebfccc5dd08c68fcf4495e5 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl.cc
@@ -35,6 +35,7 @@
 #include "webrtc/modules/audio_processing/level_controller/level_controller.h"
 #include "webrtc/modules/audio_processing/level_estimator_impl.h"
 #include "webrtc/modules/audio_processing/noise_suppression_impl.h"
+#include "webrtc/modules/audio_processing/residual_echo_detector.h"
 #include "webrtc/modules/audio_processing/transient/transient_suppressor.h"
 #include "webrtc/modules/audio_processing/voice_detection_impl.h"
 #include "webrtc/modules/include/module_common_types.h"
@@ -130,6 +131,7 @@ bool AudioProcessingImpl::ApmSubmoduleStates::Update(
     bool high_pass_filter_enabled,
     bool echo_canceller_enabled,
     bool mobile_echo_controller_enabled,
+    bool residual_echo_detector_enabled,
     bool noise_suppressor_enabled,
     bool intelligibility_enhancer_enabled,
     bool beamformer_enabled,
@@ -143,6 +145,8 @@ bool AudioProcessingImpl::ApmSubmoduleStates::Update(
   changed |= (echo_canceller_enabled != echo_canceller_enabled_);
   changed |=
       (mobile_echo_controller_enabled != mobile_echo_controller_enabled_);
+  changed |=
+      (residual_echo_detector_enabled != residual_echo_detector_enabled_);
   changed |= (noise_suppressor_enabled != noise_suppressor_enabled_);
   changed |=
       (intelligibility_enhancer_enabled != intelligibility_enhancer_enabled_);
@@ -158,6 +162,7 @@ bool AudioProcessingImpl::ApmSubmoduleStates::Update(
     high_pass_filter_enabled_ = high_pass_filter_enabled;
     echo_canceller_enabled_ = echo_canceller_enabled;
     mobile_echo_controller_enabled_ = mobile_echo_controller_enabled;
+    residual_echo_detector_enabled_ = residual_echo_detector_enabled;
     noise_suppressor_enabled_ = noise_suppressor_enabled;
     intelligibility_enhancer_enabled_ = intelligibility_enhancer_enabled;
     beamformer_enabled_ = beamformer_enabled;
@@ -220,6 +225,7 @@ struct AudioProcessingImpl::ApmPublicSubmodules {
 
   // Accessed internally from both render and capture.
   std::unique_ptr<TransientSuppressor> transient_suppressor;
+  std::unique_ptr<ResidualEchoDetector> residual_echo_detector;

[peah-webrtc, 2016/10/13 10:11:17]

It would be better to place this among the private submodules.

The partitioning public and private is based on the fact that the api of the
public submodules is accessible outside of the APM, while the private submodules
can only be accessed from inside APM. In the long run, we would like all
submodules to be private.

[ivoc, 2016/10/13 10:31:25]

I did try placing it in the private submodules, but I ran into the issue that
private_submodules_ is guarded by the capture lock, which means that we would
need to hold the capture lock on the render side while accessing the residual
echo detector. I thought that sounded like a bad idea, so I placed it here
instead. What do you think is the best solution?

[peah-webrtc, 2016/10/13 10:50:27]

I think you should remove the guard for that for the private submodules struct.
It is basically only there because it was possible to add it when the locking
scheme was introduced.

I have actually also removed it in another of the CLs I'm working on, but it is
fully fine to do it now.

 #if WEBRTC_INTELLIGIBILITY_ENHANCER
   std::unique_ptr<IntelligibilityEnhancer> intelligibility_enhancer;
 #endif
@@ -297,6 +303,8 @@ AudioProcessingImpl::AudioProcessingImpl(const webrtc::Config& config,
     public_submodules_->gain_control_for_experimental_agc.reset(
         new GainControlForExperimentalAgc(
             public_submodules_->gain_control.get(), &crit_capture_));
+    public_submodules_->residual_echo_detector.reset(
+        new ResidualEchoDetector(&crit_render_, &crit_capture_));
 
     // TODO(peah): Move this creation to happen only when the level controller
     // is enabled.
@@ -459,6 +467,7 @@ int AudioProcessingImpl::InitializeLocked() {
   public_submodules_->voice_detection->Initialize(proc_split_sample_rate_hz());
   public_submodules_->level_estimator->Initialize();
   InitializeLevelController();
+  InitializeResidualEchoDetector();
 
 #ifdef WEBRTC_AUDIOPROC_DEBUG_DUMP
   if (debug_dump_.debug_file->is_open()) {
@@ -700,6 +709,7 @@ int AudioProcessingImpl::ProcessStream(const float* const* src,
     public_submodules_->echo_cancellation->ReadQueuedRenderData();
     public_submodules_->echo_control_mobile->ReadQueuedRenderData();
     public_submodules_->gain_control->ReadQueuedRenderData();
+    public_submodules_->residual_echo_detector->ReadQueuedRenderData();
 
     if (!src || !dest) {
       return kNullPointerError;
@@ -770,6 +780,7 @@ int AudioProcessingImpl::ProcessStream(AudioFrame* frame) {
     public_submodules_->echo_cancellation->ReadQueuedRenderData();
     public_submodules_->echo_control_mobile->ReadQueuedRenderData();
     public_submodules_->gain_control->ReadQueuedRenderData();
+    public_submodules_->residual_echo_detector->ReadQueuedRenderData();
   }
 
   if (!frame) {
@@ -932,6 +943,11 @@ int AudioProcessingImpl::ProcessCaptureStreamLocked() {
   RETURN_ON_ERR(public_submodules_->echo_control_mobile->ProcessCaptureAudio(
       capture_buffer, stream_delay_ms()));
 
+  if (config_.residual_echo_detector.enabled) {
+    public_submodules_->residual_echo_detector->AnalyzeCaptureAudio(
+        capture_buffer);
+  }
+
   if (capture_nonlocked_.beamformer_enabled) {
     private_submodules_->beamformer->PostFilter(capture_buffer->split_data_f());
   }
@@ -1134,6 +1150,10 @@ int AudioProcessingImpl::ProcessRenderStreamLocked() {
       public_submodules_->echo_cancellation->ProcessRenderAudio(render_buffer));
   RETURN_ON_ERR(public_submodules_->echo_control_mobile->ProcessRenderAudio(
       render_buffer));
+  if (config_.residual_echo_detector.enabled) {
+    public_submodules_->residual_echo_detector->AnalyzeRenderAudio(
+        render_buffer);
+  }
   if (!constants_.use_experimental_agc) {
     RETURN_ON_ERR(
         public_submodules_->gain_control->ProcessRenderAudio(render_buffer));
@@ -1310,6 +1330,7 @@ bool AudioProcessingImpl::UpdateActiveSubmoduleStates() {
       public_submodules_->high_pass_filter->is_enabled(),
       public_submodules_->echo_cancellation->is_enabled(),
       public_submodules_->echo_control_mobile->is_enabled(),
+      config_.residual_echo_detector.enabled,
       public_submodules_->noise_suppression->is_enabled(),
       capture_nonlocked_.intelligibility_enabled,
       capture_nonlocked_.beamformer_enabled,
@@ -1359,6 +1380,10 @@ void AudioProcessingImpl::InitializeLevelController() {
   private_submodules_->level_controller->Initialize(proc_sample_rate_hz());
 }
 
+void AudioProcessingImpl::InitializeResidualEchoDetector() {
+  public_submodules_->residual_echo_detector->Initialize(proc_sample_rate_hz());
+}
+
 void AudioProcessingImpl::MaybeUpdateHistograms() {
   static const int kMinDiffDelayMs = 60;