Finalization of the first version of EchoCanceller 3

webrtc/modules/audio_processing/aec3/residual_echo_estimator.cc

Index: webrtc/modules/audio_processing/aec3/residual_echo_estimator.cc
diff --git a/webrtc/modules/audio_processing/aec3/residual_echo_estimator.cc b/webrtc/modules/audio_processing/aec3/residual_echo_estimator.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e84439dbd9778008372bc8632c8e8d31f0827ec8
--- /dev/null
+++ b/webrtc/modules/audio_processing/aec3/residual_echo_estimator.cc
@@ -0,0 +1,76 @@
+/*
+ *  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/residual_echo_estimator.h"
+
+#include <math.h>
+#include <vector>
+
+#include "webrtc/base/checks.h"
+
+namespace webrtc {
+
+ResidualEchoEstimator::ResidualEchoEstimator() {
+  echo_path_gain_.fill(0.f);
+}
+
+ResidualEchoEstimator::~ResidualEchoEstimator() = default;
+
+void ResidualEchoEstimator::Estimate(
+    const AecState& aec_state,
+    const FftBuffer& X_buffer,
+    const std::vector<std::array<float, kFftLengthBy2Plus1>>& H2,
+    const std::array<float, kFftLengthBy2Plus1>& E2_main,
+    const std::array<float, kFftLengthBy2Plus1>& E2_shadow,
+    const std::array<float, kFftLengthBy2Plus1>& S2_linear,
+    const std::array<float, kFftLengthBy2Plus1>& S2_fallback,
+    const std::array<float, kFftLengthBy2Plus1>& Y2,
+    const DelayHandler& delay_handler,
+    std::array<float, kFftLengthBy2Plus1>* R2) {
+  const rtc::Optional<size_t>& linear_filter_based_delay =
+      delay_handler.FilterDelay();
+  if (linear_filter_based_delay) {
+    std::copy(H2[*linear_filter_based_delay].begin(),
+              H2[*linear_filter_based_delay].end(), echo_path_gain_.begin());
+  }
+
+  const std::array<bool, kFftLengthBy2Plus1>& bands_with_reliable_filter =
+      aec_state.BandsWithReliableFilter();
+
+  if (aec_state.UsableLinearEstimate()) {
+    const std::array<float, kFftLengthBy2Plus1>& erle = aec_state.Erle();
+
+    for (size_t k = 0; k < R2->size(); ++k) {
+      RTC_DCHECK_LT(0.f, erle[k]);
+      (*R2)[k] = bands_with_reliable_filter[k] ? S2_linear[k] / erle[k]
+                                               : S2_fallback[k];
+    }
+
+  } else if (aec_state.ModelBasedAecFeasible()) {
+    const rtc::Optional<size_t>& provided_delay = delay_handler.ExternalDelay();
+    RTC_DCHECK(provided_delay);
+    const std::array<float, kFftLengthBy2Plus1>& X2 =
+        X_buffer.Spectrum(*provided_delay);
+    for (size_t k = 0; k < R2->size(); ++k) {
+      (*R2)[k] = bands_with_reliable_filter[k] ? echo_path_gain_[k] * X2[k]
+                                               : S2_fallback[k];
+    }
+  } else if (aec_state.EchoLeakageDetected()) {
+    if (aec_state.ActiveRender()) {
+      std::copy(Y2.begin(), Y2.end(), R2->begin());
+    } else {
+      R2->fill(0.f);
+    }
+  } else {
+    R2->fill(0.f);
+  }
+}
+
+}  // namespace webrtc