Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/audio_processing_impl.cc

 /*
  *  Copyright (c) 2012 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 421 matching lines @@
   // Called from both threads. Thread check is therefore not possible.
   if (processing_config == formats_.api_format && !force_initialization) {
     return kNoError;
   }
 
   rtc::CritScope cs_capture(&crit_capture_);
   return InitializeLocked(processing_config);
 }
 
 int AudioProcessingImpl::InitializeLocked() {
-  int capture_audiobuffer_num_channels;
-  if (private_submodules_->echo_canceller3) {
-    // TODO(peah): Ensure that the echo canceller can operate on more than one
-    // microphone channel.
-    RTC_DCHECK(!capture_nonlocked_.beamformer_enabled);
-    capture_audiobuffer_num_channels = 1;
-  } else {
-    capture_audiobuffer_num_channels =
-        capture_nonlocked_.beamformer_enabled
-            ? formats_.api_format.input_stream().num_channels()
-            : formats_.api_format.output_stream().num_channels();
-  }
+  const int capture_audiobuffer_num_channels =
+      capture_nonlocked_.beamformer_enabled
+          ? formats_.api_format.input_stream().num_channels()
+          : formats_.api_format.output_stream().num_channels();
+
   const int render_audiobuffer_num_output_frames =
       formats_.api_format.reverse_output_stream().num_frames() == 0
           ? formats_.render_processing_format.num_frames()
           : formats_.api_format.reverse_output_stream().num_frames();
   if (formats_.api_format.reverse_input_stream().num_channels() > 0) {
     render_.render_audio.reset(new AudioBuffer(
         formats_.api_format.reverse_input_stream().num_frames(),
         formats_.api_format.reverse_input_stream().num_channels(),
         formats_.render_processing_format.num_frames(),
         formats_.render_processing_format.num_channels(),
@@ skipping 105 matching lines @@
   capture_nonlocked_.capture_processing_format =
       StreamConfig(capture_processing_rate);
 
   int render_processing_rate = FindNativeProcessRateToUse(
       std::min(formats_.api_format.reverse_input_stream().sample_rate_hz(),
                formats_.api_format.reverse_output_stream().sample_rate_hz()),
       submodule_states_.CaptureMultiBandSubModulesActive() ||
           submodule_states_.RenderMultiBandSubModulesActive());
   // TODO(aluebs): Remove this restriction once we figure out why the 3-band
   // splitting filter degrades the AEC performance.
-  // TODO(peah): Verify that the band splitting is needed for the AEC3.
-  if (render_processing_rate > kSampleRate32kHz &&
-      !capture_nonlocked_.echo_canceller3_enabled) {
+  if (render_processing_rate > kSampleRate32kHz) {
     render_processing_rate = submodule_states_.RenderMultiBandProcessingActive()
                                  ? kSampleRate32kHz
                                  : kSampleRate16kHz;
   }
   // If the forward sample rate is 8 kHz, the render stream is also processed
   // at this rate.
   if (capture_nonlocked_.capture_processing_format.sample_rate_hz() ==
       kSampleRate8kHz) {
     render_processing_rate = kSampleRate8kHz;
   } else {
@@ skipping 563 matching lines @@
         capture_buffer->channels()[0], capture_buffer->num_channels(),
         capture_nonlocked_.capture_processing_format.num_frames());
   }
 
   if (submodule_states_.CaptureMultiBandSubModulesActive() &&
       SampleRateSupportsMultiBand(
           capture_nonlocked_.capture_processing_format.sample_rate_hz())) {
     capture_buffer->SplitIntoFrequencyBands();
   }
 
+  if (private_submodules_->echo_canceller3) {
+    // Force down-mixing of the number of channels after the detection of
+    // capture signal saturation.
+    // TODO(peah): Look into ensuring that this kind of tampering with the
+    // AudioBuffer functionality should not be needed.
+    capture_buffer->set_num_channels(1);
+  }
+
   if (capture_nonlocked_.beamformer_enabled) {
     private_submodules_->beamformer->AnalyzeChunk(
         *capture_buffer->split_data_f());
     // Discards all channels by the leftmost one.
     capture_buffer->set_num_channels(1);
   }
 
   // TODO(peah): Move the AEC3 low-cut filter to this place.
   if (private_submodules_->low_cut_filter &&
       !private_submodules_->echo_canceller3) {
@@ skipping 811 matching lines @@
       capture_processing_format(kSampleRate16kHz),
       split_rate(kSampleRate16kHz) {}
 
 AudioProcessingImpl::ApmCaptureState::~ApmCaptureState() = default;
 
 AudioProcessingImpl::ApmRenderState::ApmRenderState() = default;
 
 AudioProcessingImpl::ApmRenderState::~ApmRenderState() = default;
 
 }  // namespace webrtc