Major AEC3 render pipeline changes

webrtc/modules/audio_processing/aec3/decimator_by_4.h

 /*
  *  Copyright (c) 2017 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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_BY_4_H_
 #define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_BY_4_H_
 
 #include <array>
 
 #include "webrtc/base/array_view.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/audio_processing/aec3/aec3_common.h"
 #include "webrtc/modules/audio_processing/aec3/cascaded_biquad_filter.h"
 
 namespace webrtc {
 
 // Provides functionality for decimating a signal by 4.
 class DecimatorBy4 {
  public:
   DecimatorBy4();
 
   // Downsamples the signal.
-  void Decimate(rtc::ArrayView<const float> in,
-                std::array<float, kSubBlockSize>* out);
+  void Decimate(rtc::ArrayView<const float> in, rtc::ArrayView<float> out);

[peah-webrtc, 2017/03/30 05:36:55]

This is needed due to that now multi-band render blocks are processed in the
render pipeline. I expect this to be changed back once the multi-band blocks are
changed from being vectors of vectors.

 
  private:
   CascadedBiQuadFilter low_pass_filter_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DecimatorBy4);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_DECIMATOR_BY_4_H_