Correction of the AEC3 underrun behavior and minor other corrections

webrtc/modules/audio_processing/aec3/block_processor.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.
  */
 #include "webrtc/modules/audio_processing/aec3/block_processor.h"
@@ skipping 83 matching lines @@
   data_dumper_->DumpWav("aec3_processblock_capture_input2", kBlockSize,
                         &(*capture_block)[0][0],
                         LowestBandRate(sample_rate_hz_), 1);
 
   bool render_buffer_underrun = false;
   if (render_buffer_overrun_occurred_) {
     // Reset the render buffers and the alignment functionality when there has
     // been a render buffer overrun as the buffer alignment may be noncausal.
     delay_controller_->Reset();
     render_buffer_->Reset();
-  } else {

[peah-webrtc, 2017/04/06 13:39:08]

Before this change, the AEC leaked echo for one block each time there was an
overrun. That is corrected by this change.

-    // Update the render buffers with new render data, filling the buffers with
-    // empty blocks when there is no render data available.
-    render_buffer_underrun = !render_buffer_->UpdateBuffers();
+  }
 
-    // Compute and and apply the render delay required to achieve proper signal
-    // alignment.
-    const size_t old_delay = render_buffer_->Delay();
-    const size_t new_delay = delay_controller_->GetDelay(
-        render_buffer_->GetDownsampledRenderBuffer(), (*capture_block)[0]);
-    render_buffer_->SetDelay(new_delay);
-    const size_t achieved_delay = render_buffer_->Delay();
+  // Update the render buffers with new render data, filling the buffers with
+  // empty blocks when there is no render data available.
+  render_buffer_underrun = !render_buffer_->UpdateBuffers();
 
-    // Inform the delay controller of the actually set delay to allow it to
-    // properly react to a non-feasible delay.
-    delay_controller_->SetDelay(achieved_delay);
+  // Compute and and apply the render delay required to achieve proper signal
+  // alignment.
+  const size_t old_delay = render_buffer_->Delay();
+  const size_t new_delay = delay_controller_->GetDelay(
+      render_buffer_->GetDownsampledRenderBuffer(), (*capture_block)[0]);
+  render_buffer_->SetDelay(new_delay);
+  const size_t achieved_delay = render_buffer_->Delay();
 
-    // Remove the echo from the capture signal.
-    echo_remover_->ProcessCapture(
-        delay_controller_->AlignmentHeadroomSamples(),
-        EchoPathVariability(echo_path_gain_change,
-                            old_delay != achieved_delay ||
-                                old_delay != new_delay ||
-                                render_buffer_overrun_occurred_),
-        capture_signal_saturation, render_buffer_->GetRenderBuffer(),
-        capture_block);
-  }
+  // Inform the delay controller of the actually set delay to allow it to
+  // properly react to a non-feasible delay.
+  delay_controller_->SetDelay(achieved_delay);
+
+  // Remove the echo from the capture signal.
+  echo_remover_->ProcessCapture(
+      delay_controller_->AlignmentHeadroomSamples(),
+      EchoPathVariability(echo_path_gain_change,
+                          old_delay != achieved_delay ||
+                              old_delay != new_delay ||
+                              render_buffer_overrun_occurred_),
+      capture_signal_saturation, render_buffer_->GetRenderBuffer(),
+      capture_block);
 
   // Update the metrics.
   metrics_.UpdateCapture(render_buffer_underrun);
 
   render_buffer_overrun_occurred_ = false;
 }
 
 void BlockProcessorImpl::BufferRender(std::vector<std::vector<float>>* block) {
   RTC_DCHECK(block);
   RTC_DCHECK_EQ(NumBandsForRate(sample_rate_hz_), block->size());
@@ skipping 53 matching lines @@
     int sample_rate_hz,
     std::unique_ptr<RenderDelayBuffer> render_buffer,
     std::unique_ptr<RenderDelayController> delay_controller,
     std::unique_ptr<EchoRemover> echo_remover) {
   return new BlockProcessorImpl(sample_rate_hz, std::move(render_buffer),
                                 std::move(delay_controller),
                                 std::move(echo_remover));
 }
 
 }  // namespace webrtc