moving_detection.h

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/******************************************************************************
 * Copyright 2020 The Apollo Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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#include <deque>
#include <vector>
#include <complex>

#include "modules/audio/proto/audio.pb.h"

namespace apollo {
namespace audio {

class MovingDetection {
 public:
  MovingDetection() = default;

  std::vector<std::complex<double>> fft1d(const std::vector<double>& signals);

  MovingResult Detect(const std::vector<std::vector<double>>& signals);

  MovingResult DetectSingleChannel(
      const std::size_t channel_index, const std::vector<double>& signal);

 private:
  class SignalStat {
   public:
    SignalStat(double power, int top_frequency)
        : power_(power), top_frequency_(top_frequency) {}
    double power() const { return power_; }
    int top_frequency() const { return top_frequency_; }
   private:
    double power_;
    int top_frequency_;
  };

  SignalStat GetSignalStat(
      const std::vector<std::complex<double>>& fft_results,
      const int start_frequency);

  MovingResult AnalyzePower(const std::deque<SignalStat>& signal_stats);

  MovingResult AnalyzeTopFrequence(const std::deque<SignalStat>& signal_stats);

  std::vector<std::deque<SignalStat>> signal_stats_;
};

}  // namespace audio
}  // namespace apollo