subband_nearend_detector.h

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/*

 *  Copyright (c) 2019 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_SUBBAND_NEAREND_DETECTOR_H_

#define MODULES_AUDIO_PROCESSING_AEC3_SUBBAND_NEAREND_DETECTOR_H_

#include <vector>

#include "api/array_view.h"

#include "api/audio/echo_canceller3_config.h"

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

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

namespace webrtc {

// Class for selecting whether the suppressor is in the nearend or echo state.

class SubbandNearendDetector : public NearendDetector {

 public:

  SubbandNearendDetector(

      const EchoCanceller3Config::Suppressor::SubbandNearendDetection& config,

      size_t num_capture_channels);

  // Returns whether the current state is the nearend state.

  bool IsNearendState() const override { return nearend_state_; }

  // Updates the state selection based on latest spectral estimates.

  void Update(rtc::ArrayView<const std::array<float, kFftLengthBy2Plus1>>

                  nearend_spectrum,

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

                  residual_echo_spectrum,

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

                  comfort_noise_spectrum,

              bool initial_state) override;

 private:

  const EchoCanceller3Config::Suppressor::SubbandNearendDetection config_;

  const size_t num_capture_channels_;

  std::vector<aec3::MovingAverage> nearend_smoothers_;

  const float one_over_subband_length1_;

  const float one_over_subband_length2_;

  bool nearend_state_ = false;

};

}  // namespace webrtc

#endif  // MODULES_AUDIO_PROCESSING_AEC3_SUBBAND_NEAREND_DETECTOR_H_