third_party/WebKit/Source/modules/webaudio/BiquadProcessor.h

/*
 * Copyright (C) 2010, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1.  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

#ifndef BiquadProcessor_h
#define BiquadProcessor_h

#include "modules/webaudio/AudioNode.h"
#include "modules/webaudio/AudioParam.h"
#include "platform/audio/AudioDSPKernel.h"
#include "platform/audio/AudioDSPKernelProcessor.h"
#include "platform/audio/Biquad.h"
#include "wtf/RefPtr.h"
#include <memory>

namespace blink {

// BiquadProcessor is an AudioDSPKernelProcessor which uses Biquad objects to implement several common filters.

class BiquadProcessor final : public AudioDSPKernelProcessor {
 public:
  // This values are used in histograms and should not be renumbered or deleted.
  enum FilterType {
    LowPass = 0,
    HighPass = 1,
    BandPass = 2,
    LowShelf = 3,
    HighShelf = 4,
    Peaking = 5,
    Notch = 6,
    Allpass = 7
  };

  BiquadProcessor(float sampleRate,
                  size_t numberOfChannels,
                  AudioParamHandler& frequency,
                  AudioParamHandler& q,
                  AudioParamHandler& gain,
                  AudioParamHandler& detune);
  ~BiquadProcessor() override;

  std::unique_ptr<AudioDSPKernel> createKernel() override;

  void process(const AudioBus* source,
               AudioBus* destination,
               size_t framesToProcess) override;

  // Get the magnitude and phase response of the filter at the given
  // set of frequencies (in Hz). The phase response is in radians.
  void getFrequencyResponse(int nFrequencies,
                            const float* frequencyHz,
                            float* magResponse,
                            float* phaseResponse);

  void checkForDirtyCoefficients();

  bool filterCoefficientsDirty() const { return m_filterCoefficientsDirty; }
  bool hasSampleAccurateValues() const { return m_hasSampleAccurateValues; }

  AudioParamHandler& parameter1() { return *m_parameter1; }
  AudioParamHandler& parameter2() { return *m_parameter2; }
  AudioParamHandler& parameter3() { return *m_parameter3; }
  AudioParamHandler& parameter4() { return *m_parameter4; }

  FilterType type() const { return m_type; }
  void setType(FilterType);

 private:
  FilterType m_type;

  RefPtr<AudioParamHandler> m_parameter1;
  RefPtr<AudioParamHandler> m_parameter2;
  RefPtr<AudioParamHandler> m_parameter3;
  RefPtr<AudioParamHandler> m_parameter4;

  // so DSP kernels know when to re-compute coefficients
  bool m_filterCoefficientsDirty;

  // Set to true if any of the filter parameters are sample-accurate.
  bool m_hasSampleAccurateValues;
};

}  // namespace blink

#endif  // BiquadProcessor_h