Major AEC3 render pipeline changes

webrtc/modules/audio_processing/aec3/aec3_common.h

 /*
  *  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.
  */
 
@@ skipping 13 matching lines @@
 #define ALIGN16_END __attribute__((aligned(16)))
 #endif
 
 enum class Aec3Optimization { kNone, kSse2 };
 
 constexpr int kMetricsReportingIntervalBlocks = 10 * 250;
 constexpr int kMetricsComputationBlocks = 9;
 constexpr int kMetricsCollectionBlocks =
     kMetricsReportingIntervalBlocks - kMetricsComputationBlocks;
 
+constexpr int kAdaptiveFilterLength = 12;

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

The adaptive filter lengths has now been fixed into a constant (which is how it
is actually used). This change will take effect in the next CL, and the code
will be further refactored accordingly after that.

+
 constexpr size_t kFftLengthBy2 = 64;
 constexpr size_t kFftLengthBy2Plus1 = kFftLengthBy2 + 1;
 constexpr size_t kFftLengthBy2Minus1 = kFftLengthBy2 - 1;
 constexpr size_t kFftLength = 2 * kFftLengthBy2;
 
 constexpr size_t kMaxNumBands = 3;
 constexpr size_t kSubFrameLength = 80;
 
 constexpr size_t kBlockSize = kFftLengthBy2;
 constexpr size_t kExtendedBlockSize = 2 * kFftLengthBy2;
 constexpr size_t kSubBlockSize = 16;
 
+constexpr size_t kNumMatchedFilters = 4;

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

The matched filter number, as well as the alignment of that, has now as well
been set as a constant. That makes sense, as it is how it is actually used.
Apart from that, however, it was a necessity as the lengths of the render
buffers are now are no longer fully independent

+constexpr size_t kMatchedFilterWindowSizeSubBlocks = 32;
+constexpr size_t kMatchedFilterAlignmentShiftSizeSubBlocks =
+    kMatchedFilterWindowSizeSubBlocks * 3 / 4;
+constexpr size_t kDownsampledRenderBufferSize =
+    kSubBlockSize *
+    (kMatchedFilterAlignmentShiftSizeSubBlocks * kNumMatchedFilters +
+     kMatchedFilterWindowSizeSubBlocks +
+     1);
+
+constexpr size_t kRenderDelayBufferSize =
+    (3 * kDownsampledRenderBufferSize) / (4 * kSubBlockSize);
+
+constexpr size_t kMaxApiCallsJitterBlocks = 9;
+constexpr size_t kRenderTransferQueueSize = kMaxApiCallsJitterBlocks / 2;
+
 constexpr size_t NumBandsForRate(int sample_rate_hz) {
   return static_cast<size_t>(sample_rate_hz == 8000 ? 1
                                                     : sample_rate_hz / 16000);
 }
 constexpr int LowestBandRate(int sample_rate_hz) {
   return sample_rate_hz == 8000 ? sample_rate_hz : 16000;
 }
 
 constexpr bool ValidFullBandRate(int sample_rate_hz) {
   return sample_rate_hz == 8000 || sample_rate_hz == 16000 ||
@@ skipping 23 matching lines @@
 static_assert(ValidFullBandRate(32000),
               "Test that 32 kHz is a valid sample rate");
 static_assert(ValidFullBandRate(48000),
               "Test that 48 kHz is a valid sample rate");
 static_assert(!ValidFullBandRate(8001),
               "Test that 8001 Hz is not a valid sample rate");
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_AEC3_COMMON_H_