erl_estimator.h - mozsearch

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/*

 *  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_ERL_ESTIMATOR_H_

#define MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_

#include <stddef.h>

#include <array>

#include <vector>

#include "api/array_view.h"

#include "modules/audio_processing/aec3/aec3_common.h"

namespace webrtc {

// Estimates the echo return loss based on the signal spectra.

class ErlEstimator {

 public:

  explicit ErlEstimator(size_t startup_phase_length_blocks_);

  ~ErlEstimator();

  ErlEstimator(const ErlEstimator&) = delete;

  ErlEstimator& operator=(const ErlEstimator&) = delete;

  // Resets the ERL estimation.

  void Reset();

  // Updates the ERL estimate.

  void Update(const std::vector<bool>& converged_filters,

              rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>>

                  render_spectra,

              rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>>

                  capture_spectra);

  // Returns the most recent ERL estimate.

  const std::array<float, kFftLengthBy2Plus1>& Erl() const { return erl_; }

  float ErlTimeDomain() const { return erl_time_domain_; }

 private:

  const size_t startup_phase_length_blocks__;

  std::array<float, kFftLengthBy2Plus1> erl_;

  std::array<int, kFftLengthBy2Minus1> hold_counters_;

  float erl_time_domain_;

  int hold_counter_time_domain_;

  size_t blocks_since_reset_ = 0;

};

}  // namespace webrtc

#endif  // MODULES_AUDIO_PROCESSING_AEC3_ERL_ESTIMATOR_H_