Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/subtractor.cc

+/*
+ *  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.
+ */
+
+#include "webrtc/modules/audio_processing/aec3/subtractor.h"
+
+#include <algorithm>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/modules/audio_processing/logging/apm_data_dumper.h"
+
+namespace webrtc {
+
+namespace {
+
+void ComputeError(const Aec3Fft& fft,
+                  const FftData& S,
+                  rtc::ArrayView<const float> y,
+                  std::array<float, kBlockSize>* e,
+                  FftData* E) {
+  std::array<float, kFftLength> s;
+  fft.Ifft(S, &s);
+  constexpr float kScale = 1.0f / kFftLengthBy2;
+  std::transform(y.begin(), y.end(), s.begin() + kFftLengthBy2, e->begin(),
+                 [&](float a, float b) { return a - b * kScale; });
+  std::for_each(e->begin(), e->end(), [](float& a) {
+    a = std::max(std::min(a, 32767.0f), -32768.0f);
+  });
+  fft.ZeroPaddedFft(*e, E);
+}
+}  // namespace
+
+std::vector<size_t> Subtractor::NumBlocksInRenderSums() const {
+  if (kMainFilterLength != kShadowFilterLength) {
+    return {kMainFilterLength, kShadowFilterLength};
+  } else {
+    return {kMainFilterLength};
+  }
+}
+
+Subtractor::Subtractor(ApmDataDumper* data_dumper,
+                       Aec3Optimization optimization)
+    : data_dumper_(data_dumper),
+      optimization_(optimization),
+      main_filter_(kMainFilterLength, true, optimization, data_dumper_),
+      shadow_filter_(kShadowFilterLength, false, optimization, data_dumper_) {
+  RTC_DCHECK(data_dumper_);
+}
+
+Subtractor::~Subtractor() {}
+
+void Subtractor::HandleEchoPathChange(
+    const EchoPathVariability& echo_path_variability) {
+  if (echo_path_variability.AudioPathChanged()) {
+    if (echo_path_variability.delay_change) {
+      main_filter_.HandleEchoPathChange();
+      shadow_filter_.HandleEchoPathChange();
+      G_main_.HandleEchoPathChange();
+    }
+  }
+}
+
+void Subtractor::Process(const FftBuffer& render_buffer,
+                         const rtc::ArrayView<const float> capture,
+                         const RenderSignalAnalyzer& render_signal_analyzer,
+                         bool saturation,
+                         SubtractorOutput* output) {
+  RTC_DCHECK_EQ(kBlockSize, capture.size());
+  rtc::ArrayView<const float> y = capture;
+  const FftBuffer& X_buffer = render_buffer;
+  FftData& E_main = output->E_main;
+  FftData& E_shadow = output->E_shadow;
+  std::array<float, kBlockSize>& e_main = output->e_main;
+  std::array<float, kBlockSize>& e_shadow = output->e_shadow;
+
+  FftData S;
+  FftData& G = S;
+
+  // Form and analyze the output of the main filter.
+  main_filter_.Filter(X_buffer, &S);
+  ComputeError(fft_, S, y, &e_main, &E_main);
+
+  // Form and analyze the output of the shadow filter.
+  shadow_filter_.Filter(X_buffer, &S);
+  ComputeError(fft_, S, y, &e_shadow, &E_shadow);
+
+  // Compute spectra for future use.
+  E_main.Spectrum(optimization_, &output->E2_main);
+  E_shadow.Spectrum(optimization_, &output->E2_shadow);
+
+  // Update the main filter.
+  G_main_.Compute(X_buffer, render_signal_analyzer, *output, main_filter_,
+                  saturation, &G);
+  main_filter_.Adapt(X_buffer, G);
+  data_dumper_->DumpRaw("aec3_subtractor_G_main", G.re);
+  data_dumper_->DumpRaw("aec3_subtractor_G_main", G.im);
+
+  // Update the shadow filter.
+  G_shadow_.Compute(X_buffer, render_signal_analyzer, E_shadow,
+                    shadow_filter_.SizePartitions(), saturation, &G);
+  shadow_filter_.Adapt(X_buffer, G);
+  data_dumper_->DumpRaw("aec3_subtractor_G_shadow", G.re);
+  data_dumper_->DumpRaw("aec3_subtractor_G_shadow", G.im);
+
+  main_filter_.DumpFilter("aec3_subtractor_H_main");
+  shadow_filter_.DumpFilter("aec3_subtractor_H_shadow");
+}
+
+}  // namespace webrtc