1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/webaudio/blink/PeriodicWave.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,106 @@
1.4 +/*
1.5 + * Copyright (C) 2012 Google Inc. All rights reserved.
1.6 + *
1.7 + * Redistribution and use in source and binary forms, with or without
1.8 + * modification, are permitted provided that the following conditions
1.9 + * are met:
1.10 + *
1.11 + * 1. Redistributions of source code must retain the above copyright
1.12 + * notice, this list of conditions and the following disclaimer.
1.13 + * 2. Redistributions in binary form must reproduce the above copyright
1.14 + * notice, this list of conditions and the following disclaimer in the
1.15 + * documentation and/or other materials provided with the distribution.
1.16 + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
1.17 + * its contributors may be used to endorse or promote products derived
1.18 + * from this software without specific prior written permission.
1.19 + *
1.20 + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
1.21 + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1.22 + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1.23 + * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
1.24 + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
1.25 + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
1.26 + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
1.27 + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.28 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1.29 + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.30 + */
1.31 +
1.32 +#ifndef PeriodicWave_h
1.33 +#define PeriodicWave_h
1.34 +
1.35 +#include "mozilla/dom/OscillatorNodeBinding.h"
1.36 +#include <nsAutoPtr.h>
1.37 +#include <nsTArray.h>
1.38 +#include "mozilla/MemoryReporting.h"
1.39 +
1.40 +namespace WebCore {
1.41 +
1.42 +typedef nsTArray<float> AudioFloatArray;
1.43 +
1.44 +class PeriodicWave {
1.45 +public:
1.46 + static PeriodicWave* createSine(float sampleRate);
1.47 + static PeriodicWave* createSquare(float sampleRate);
1.48 + static PeriodicWave* createSawtooth(float sampleRate);
1.49 + static PeriodicWave* createTriangle(float sampleRate);
1.50 +
1.51 + // Creates an arbitrary periodic wave given the frequency components
1.52 + // (Fourier coefficients).
1.53 + static PeriodicWave* create(float sampleRate,
1.54 + const float* real,
1.55 + const float* imag,
1.56 + size_t numberOfComponents);
1.57 +
1.58 + // Returns pointers to the lower and higher wave data for the pitch range
1.59 + // containing the given fundamental frequency. These two tables are in
1.60 + // adjacent "pitch" ranges where the higher table will have the maximum
1.61 + // number of partials which won't alias when played back at this
1.62 + // fundamental frequency. The lower wave is the next range containing fewer
1.63 + // partials than the higher wave. Interpolation between these two tables
1.64 + // can be made according to tableInterpolationFactor. Where values
1.65 + // from 0 -> 1 interpolate between lower -> higher.
1.66 + void waveDataForFundamentalFrequency(float, float* &lowerWaveData, float* &higherWaveData, float& tableInterpolationFactor);
1.67 +
1.68 + // Returns the scalar multiplier to the oscillator frequency to calculate
1.69 + // wave buffer phase increment.
1.70 + float rateScale() const { return m_rateScale; }
1.71 +
1.72 + unsigned periodicWaveSize() const { return m_periodicWaveSize; }
1.73 + float sampleRate() const { return m_sampleRate; }
1.74 +
1.75 + size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
1.76 +
1.77 +private:
1.78 + explicit PeriodicWave(float sampleRate);
1.79 +
1.80 + void generateBasicWaveform(mozilla::dom::OscillatorType);
1.81 +
1.82 + float m_sampleRate;
1.83 + unsigned m_periodicWaveSize;
1.84 + unsigned m_numberOfRanges;
1.85 + float m_centsPerRange;
1.86 +
1.87 + // The lowest frequency (in Hertz) where playback will include all of the
1.88 + // partials. Playing back lower than this frequency will gradually lose
1.89 + // more high-frequency information.
1.90 + // This frequency is quite low (~10Hz @ // 44.1KHz)
1.91 + float m_lowestFundamentalFrequency;
1.92 +
1.93 + float m_rateScale;
1.94 +
1.95 + unsigned numberOfRanges() const { return m_numberOfRanges; }
1.96 +
1.97 + // Maximum possible number of partials (before culling).
1.98 + unsigned maxNumberOfPartials() const;
1.99 +
1.100 + unsigned numberOfPartialsForRange(unsigned rangeIndex) const;
1.101 +
1.102 + // Creates tables based on numberOfComponents Fourier coefficients.
1.103 + void createBandLimitedTables(const float* real, const float* imag, unsigned numberOfComponents);
1.104 + nsTArray<nsAutoPtr<AudioFloatArray> > m_bandLimitedTables;
1.105 +};
1.106 +
1.107 +} // namespace WebCore
1.108 +
1.109 +#endif // PeriodicWave_h
