PeriodicWave.h - mozsearch

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/*

 * 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

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 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

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*/

#ifndef PeriodicWave_h

#define PeriodicWave_h

#include "mozilla/dom/OscillatorNodeBinding.h"

#include "mozilla/UniquePtr.h"

#include <nsTArray.h>

#include "AlignedTArray.h"

#include "mozilla/MemoryReporting.h"

namespace WebCore {

typedef AlignedTArray<float> AlignedAudioFloatArray;

typedef nsTArray<float> AudioFloatArray;

using mozilla::UniquePtr;

class PeriodicWave {

 public:

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WebCore::PeriodicWave);

  static already_AddRefed<PeriodicWave> createSine(float sampleRate);

  static already_AddRefed<PeriodicWave> createSquare(float sampleRate);

  static already_AddRefed<PeriodicWave> createSawtooth(float sampleRate);

  static already_AddRefed<PeriodicWave> createTriangle(float sampleRate);

  // Creates an arbitrary periodic wave given the frequency components

  // (Fourier coefficients).

  static already_AddRefed<PeriodicWave> create(float sampleRate,

                                               const float* real,

                                               const float* imag,

                                               size_t numberOfComponents,

                                               bool disableNormalization);

  // 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, size_t numberOfComponents,

                        bool disableNormalization);

  ~PeriodicWave() = default;

  void generateBasicWaveform(mozilla::dom::OscillatorType);

  float m_sampleRate;

  unsigned m_periodicWaveSize;

  unsigned m_numberOfRanges;

  float m_centsPerRange;

  unsigned m_numberOfComponents;

  UniquePtr<AudioFloatArray> m_realComponents;

  UniquePtr<AudioFloatArray> m_imagComponents;

  // 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 table for specified index based on fundamental frequency.

  void createBandLimitedTables(float fundamentalFrequency, unsigned rangeIndex);

  unsigned m_maxPartialsInBandLimitedTable;

  float m_normalizationScale;

  bool m_disableNormalization;

  nsTArray<UniquePtr<AlignedAudioFloatArray> > m_bandLimitedTables;

};

}  // namespace WebCore

#endif  // PeriodicWave_h