/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef AudioDSPKernel_h
#define AudioDSPKernel_h

#include "platform/audio/AudioDSPKernelProcessor.h"
#include "wtf/Allocator.h"

namespace blink {

// AudioDSPKernel does the processing for one channel of an
// AudioDSPKernelProcessor.

class PLATFORM_EXPORT AudioDSPKernel {
  USING_FAST_MALLOC(AudioDSPKernel);

 public:
  AudioDSPKernel(AudioDSPKernelProcessor* kernelProcessor)
      : m_kernelProcessor(kernelProcessor),
        m_sampleRate(kernelProcessor->sampleRate()) {}

  AudioDSPKernel(float sampleRate)
      : m_kernelProcessor(nullptr), m_sampleRate(sampleRate) {}

  virtual ~AudioDSPKernel();

  // Subclasses must override process() to do the processing and reset() to
  // reset DSP state.
  virtual void process(const float* source,
                       float* destination,
                       size_t framesToProcess) = 0;
  virtual void reset() = 0;

  float sampleRate() const { return m_sampleRate; }
  double nyquist() const { return 0.5 * sampleRate(); }

  AudioDSPKernelProcessor* processor() { return m_kernelProcessor; }
  const AudioDSPKernelProcessor* processor() const { return m_kernelProcessor; }

  virtual double tailTime() const = 0;
  virtual double latencyTime() const = 0;

 protected:
  // This raw pointer is safe because the AudioDSPKernelProcessor object is
  // guaranteed to be kept alive while the AudioDSPKernel object is alive.
  AudioDSPKernelProcessor* m_kernelProcessor;
  float m_sampleRate;
};

}  // namespace blink

#endif  // AudioDSPKernel_h
