Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/subtractor.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_SUBTRACTOR_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_SUBTRACTOR_H_
+
+#include <array>
+#include <algorithm>
+#include <vector>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/audio_processing/aec3/adaptive_fir_filter.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_common.h"
+#include "webrtc/modules/audio_processing/aec3/aec3_fft.h"
+#include "webrtc/modules/audio_processing/aec3/echo_path_variability.h"
+#include "webrtc/modules/audio_processing/aec3/fft_buffer.h"
+#include "webrtc/modules/audio_processing/aec3/main_filter_update_gain.h"
+#include "webrtc/modules/audio_processing/aec3/shadow_filter_update_gain.h"
+#include "webrtc/modules/audio_processing/aec3/subtractor_output.h"
+#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
+#include "webrtc/modules/audio_processing/utility/ooura_fft.h"
+
+namespace webrtc {
+
+// Proves linear echo cancellation functionality
+class Subtractor {
+ public:
+  Subtractor(ApmDataDumper* data_dumper, Aec3Optimization optimization);
+  ~Subtractor();
+
+  // Performs the echo subtraction.
+  void Process(const FftBuffer& render_buffer,
+               const rtc::ArrayView<const float> capture,
+               const RenderSignalAnalyzer& render_signal_analyzer,
+               bool saturation,
+               SubtractorOutput* output);
+
+  // Returns a vector with the number of blocks included in the render buffer
+  // sums.
+  std::vector<size_t> NumBlocksInRenderSums() const;
+
+  // Returns the minimum required farend buffer length.
+  size_t MinFarendBufferLength() const {
+    return std::max(kMainFilterSizePartitions, kShadowFilterSizePartitions);
+  }
+
+  void HandleEchoPathChange(const EchoPathVariability& echo_path_variability);
+
+  // Returns the block-wise frequency response of the main adaptive filter.
+  const std::vector<std::array<float, kFftLengthBy2Plus1>>&
+  FilterFrequencyResponse() const {
+    return main_filter_.FilterFrequencyResponse();
+  }
+
+ private:
+  const size_t kMainFilterSizePartitions = 12;

[aleloi, 2017/02/23 15:16:01]

Here's how to make it constexpr:

* declare/define as 'static constexpr size_t ... = 12' here in the .h file
* make sure the compiler allocates memory by writing 'constexpr size_t
Subtractor:...' in the .cc file.

+  const size_t kShadowFilterSizePartitions = 12;
+
+  const Aec3Fft fft_;
+  ApmDataDumper* data_dumper_;
+  const Aec3Optimization optimization_;
+  AdaptiveFirFilter main_filter_;
+  AdaptiveFirFilter shadow_filter_;
+  MainFilterUpdateGain G_main_;
+  ShadowFilterUpdateGain G_shadow_;
+
+  RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(Subtractor);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_SUBTRACTOR_H_