1 files changed, 99 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/aec3/matched_filter_lag_aggregator.h b/third_party/libwebrtc/modules/audio_processing/aec3/matched_filter_lag_aggregator.h
new file mode 100644
index 0000000000..1287b38da0
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/aec3/matched_filter_lag_aggregator.h
@@ -0,0 +1,99 @@
+/*
+ *  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 MODULES_AUDIO_PROCESSING_AEC3_MATCHED_FILTER_LAG_AGGREGATOR_H_
+#define MODULES_AUDIO_PROCESSING_AEC3_MATCHED_FILTER_LAG_AGGREGATOR_H_
+
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "api/audio/echo_canceller3_config.h"
+#include "modules/audio_processing/aec3/delay_estimate.h"
+#include "modules/audio_processing/aec3/matched_filter.h"
+
+namespace webrtc {
+
+class ApmDataDumper;
+
+// Aggregates lag estimates produced by the MatchedFilter class into a single
+// reliable combined lag estimate.
+class MatchedFilterLagAggregator {
+ public:
+  MatchedFilterLagAggregator(ApmDataDumper* data_dumper,
+                             size_t max_filter_lag,
+                             const EchoCanceller3Config::Delay& delay_config);
+
+  MatchedFilterLagAggregator() = delete;
+  MatchedFilterLagAggregator(const MatchedFilterLagAggregator&) = delete;
+  MatchedFilterLagAggregator& operator=(const MatchedFilterLagAggregator&) =
+      delete;
+
+  ~MatchedFilterLagAggregator();
+
+  // Resets the aggregator.
+  void Reset(bool hard_reset);
+
+  // Aggregates the provided lag estimates.
+  absl::optional<DelayEstimate> Aggregate(
+      const absl::optional<const MatchedFilter::LagEstimate>& lag_estimate);
+
+  // Returns whether a reliable delay estimate has been found.
+  bool ReliableDelayFound() const { return significant_candidate_found_; }
+
+  // Returns the delay candidate that is computed by looking at the highest peak
+  // on the matched filters.
+  int GetDelayAtHighestPeak() const {
+    return highest_peak_aggregator_.candidate();
+  }
+
+ private:
+  class PreEchoLagAggregator {
+   public:
+    PreEchoLagAggregator(size_t max_filter_lag, size_t down_sampling_factor);
+    void Reset();
+    void Aggregate(int pre_echo_lag);
+    int pre_echo_candidate() const { return pre_echo_candidate_; }
+    void Dump(ApmDataDumper* const data_dumper);
+
+   private:
+    const int block_size_log2_;
+    const bool penalize_high_delays_initial_phase_;
+    std::array<int, 250> histogram_data_;
+    std::vector<int> histogram_;
+    int histogram_data_index_ = 0;
+    int pre_echo_candidate_ = 0;
+    int number_updates_ = 0;
+  };
+
+  class HighestPeakAggregator {
+   public:
+    explicit HighestPeakAggregator(size_t max_filter_lag);
+    void Reset();
+    void Aggregate(int lag);
+    int candidate() const { return candidate_; }
+    rtc::ArrayView<const int> histogram() const { return histogram_; }
+
+   private:
+    std::vector<int> histogram_;
+    std::array<int, 250> histogram_data_;
+    int histogram_data_index_ = 0;
+    int candidate_ = -1;
+  };
+
+  ApmDataDumper* const data_dumper_;
+  bool significant_candidate_found_ = false;
+  const EchoCanceller3Config::Delay::DelaySelectionThresholds thresholds_;
+  const int headroom_;
+  HighestPeakAggregator highest_peak_aggregator_;
+  std::unique_ptr<PreEchoLagAggregator> pre_echo_lag_aggregator_;
+};
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_AEC3_MATCHED_FILTER_LAG_AGGREGATOR_H_