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/*
* 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 BiquadDSPKernel_h
#define BiquadDSPKernel_h
#include "platform/audio/AudioDSPKernel.h"
#include "platform/audio/Biquad.h"
#include "modules/webaudio/BiquadProcessor.h"
namespace blink {
class BiquadProcessor;
// BiquadDSPKernel is an AudioDSPKernel and is responsible for filtering one channel of a BiquadProcessor using a Biquad object.
class BiquadDSPKernel final : public AudioDSPKernel {
public:
explicit BiquadDSPKernel(BiquadProcessor* processor)
: AudioDSPKernel(processor)
{
}
// AudioDSPKernel
virtual void process(const float* source, float* dest, size_t framesToProcess) override;
virtual void reset() override { m_biquad.reset(); }
// 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);
virtual double tailTime() const override;
virtual double latencyTime() const override;
protected:
Biquad m_biquad;
BiquadProcessor* biquadProcessor() { return static_cast<BiquadProcessor*>(processor()); }
// To prevent audio glitches when parameters are changed,
// dezippering is used to slowly change the parameters.
void updateCoefficientsIfNecessary();
// Update the biquad cofficients with the given parameters
void updateCoefficients(double frequency, double Q, double gain, double detune);
private:
// Synchronize process() with getting and setting the filter coefficients.
mutable Mutex m_processLock;
};
} // namespace blink
#endif // BiquadDSPKernel_h
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