squeezelite-esp32/components/spotify/cspot/bell/main/audio-dsp/include/Gain.h

#pragma once

#include <memory>  // for unique_ptr
#include <mutex>   // for scoped_lock
#include <vector>  // for vector

#include "AudioTransform.h"   // for AudioTransform
#include "StreamInfo.h"       // for StreamInfo
#include "TransformConfig.h"  // for TransformConfig

namespace bell {
class Gain : public bell::AudioTransform {
 private:
  float gainFactor = 1.0f;

  std::vector<int> channels;

 public:
  Gain();
  ~Gain(){};

  float gainDb = 0.0;

  void configure(std::vector<int> channels, float gainDB);

  std::unique_ptr<StreamInfo> process(
      std::unique_ptr<StreamInfo> data) override;

  void reconfigure() override {
    std::scoped_lock lock(this->accessMutex);
    float gain = config->getFloat("gain");
    this->channels = config->getChannels();

    if (gainDb == gain) {
      return;
    }

    this->configure(channels, gain);
  }
};
}  // namespace bell