gecko-dev/content/media/webaudio/blink/PeriodicWave.h

107 lines
4.4 KiB
C++

/*
* Copyright (C) 2012 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE 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 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 PeriodicWave_h
#define PeriodicWave_h
#include "mozilla/dom/OscillatorNodeBinding.h"
#include <nsAutoPtr.h>
#include <nsTArray.h>
#include "mozilla/MemoryReporting.h"
namespace WebCore {
typedef nsTArray<float> AudioFloatArray;
class PeriodicWave {
public:
static PeriodicWave* createSine(float sampleRate);
static PeriodicWave* createSquare(float sampleRate);
static PeriodicWave* createSawtooth(float sampleRate);
static PeriodicWave* createTriangle(float sampleRate);
// Creates an arbitrary periodic wave given the frequency components
// (Fourier coefficients).
static PeriodicWave* create(float sampleRate,
const float* real,
const float* imag,
size_t numberOfComponents);
// Returns pointers to the lower and higher wave data for the pitch range
// containing the given fundamental frequency. These two tables are in
// adjacent "pitch" ranges where the higher table will have the maximum
// number of partials which won't alias when played back at this
// fundamental frequency. The lower wave is the next range containing fewer
// partials than the higher wave. Interpolation between these two tables
// can be made according to tableInterpolationFactor. Where values
// from 0 -> 1 interpolate between lower -> higher.
void waveDataForFundamentalFrequency(float, float* &lowerWaveData, float* &higherWaveData, float& tableInterpolationFactor);
// Returns the scalar multiplier to the oscillator frequency to calculate
// wave buffer phase increment.
float rateScale() const { return m_rateScale; }
unsigned periodicWaveSize() const { return m_periodicWaveSize; }
float sampleRate() const { return m_sampleRate; }
size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
private:
explicit PeriodicWave(float sampleRate);
void generateBasicWaveform(mozilla::dom::OscillatorType);
float m_sampleRate;
unsigned m_periodicWaveSize;
unsigned m_numberOfRanges;
float m_centsPerRange;
// The lowest frequency (in Hertz) where playback will include all of the
// partials. Playing back lower than this frequency will gradually lose
// more high-frequency information.
// This frequency is quite low (~10Hz @ // 44.1KHz)
float m_lowestFundamentalFrequency;
float m_rateScale;
unsigned numberOfRanges() const { return m_numberOfRanges; }
// Maximum possible number of partials (before culling).
unsigned maxNumberOfPartials() const;
unsigned numberOfPartialsForRange(unsigned rangeIndex) const;
// Creates tables based on numberOfComponents Fourier coefficients.
void createBandLimitedTables(const float* real, const float* imag, unsigned numberOfComponents);
nsTArray<nsAutoPtr<AudioFloatArray> > m_bandLimitedTables;
};
} // namespace WebCore
#endif // PeriodicWave_h