1 files changed, 64 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/aec3/subtractor_output_analyzer.cc b/third_party/libwebrtc/modules/audio_processing/aec3/subtractor_output_analyzer.cc
new file mode 100644
index 0000000000..baf0600161
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/aec3/subtractor_output_analyzer.cc
@@ -0,0 +1,64 @@
+/*
+ *  Copyright (c) 2018 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 "modules/audio_processing/aec3/subtractor_output_analyzer.h"
+
+#include <algorithm>
+
+#include "modules/audio_processing/aec3/aec3_common.h"
+
+namespace webrtc {
+
+SubtractorOutputAnalyzer::SubtractorOutputAnalyzer(size_t num_capture_channels)
+    : filters_converged_(num_capture_channels, false) {}
+
+void SubtractorOutputAnalyzer::Update(
+    rtc::ArrayView<const SubtractorOutput> subtractor_output,
+    bool* any_filter_converged,
+    bool* any_coarse_filter_converged,
+    bool* all_filters_diverged) {
+  RTC_DCHECK(any_filter_converged);
+  RTC_DCHECK(all_filters_diverged);
+  RTC_DCHECK_EQ(subtractor_output.size(), filters_converged_.size());
+
+  *any_filter_converged = false;
+  *any_coarse_filter_converged = false;
+  *all_filters_diverged = true;
+
+  for (size_t ch = 0; ch < subtractor_output.size(); ++ch) {
+    const float y2 = subtractor_output[ch].y2;
+    const float e2_refined = subtractor_output[ch].e2_refined;
+    const float e2_coarse = subtractor_output[ch].e2_coarse;
+
+    constexpr float kConvergenceThreshold = 50 * 50 * kBlockSize;
+    constexpr float kConvergenceThresholdLowLevel = 20 * 20 * kBlockSize;
+    bool refined_filter_converged =
+        e2_refined < 0.5f * y2 && y2 > kConvergenceThreshold;
+    bool coarse_filter_converged_strict =
+        e2_coarse < 0.05f * y2 && y2 > kConvergenceThreshold;
+    bool coarse_filter_converged_relaxed =
+        e2_coarse < 0.2f * y2 && y2 > kConvergenceThresholdLowLevel;
+    float min_e2 = std::min(e2_refined, e2_coarse);
+    bool filter_diverged = min_e2 > 1.5f * y2 && y2 > 30.f * 30.f * kBlockSize;
+    filters_converged_[ch] =
+        refined_filter_converged || coarse_filter_converged_strict;
+
+    *any_filter_converged = *any_filter_converged || filters_converged_[ch];
+    *any_coarse_filter_converged =
+        *any_coarse_filter_converged || coarse_filter_converged_relaxed;
+    *all_filters_diverged = *all_filters_diverged && filter_diverged;
+  }
+}
+
+void SubtractorOutputAnalyzer::HandleEchoPathChange() {
+  std::fill(filters_converged_.begin(), filters_converged_.end(), false);
+}
+
+}  // namespace webrtc