1 /*
2  * Copyright (C) 2012 Google Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1.  Redistributions of source code must retain the above copyright
9  *     notice, this list of conditions and the following disclaimer.
10  * 2.  Redistributions in binary form must reproduce the above copyright
11  *     notice, this list of conditions and the following disclaimer in the
12  *     documentation and/or other materials provided with the distribution.
13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14  *     its contributors may be used to endorse or promote products derived
15  *     from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef PeriodicWave_h
30 #define PeriodicWave_h
31 
32 #include "mozilla/dom/OscillatorNodeBinding.h"
33 #include <nsAutoPtr.h>
34 #include <nsTArray.h>
35 #include "AlignedTArray.h"
36 #include "mozilla/MemoryReporting.h"
37 
38 namespace WebCore {
39 
40 typedef AlignedTArray<float> AlignedAudioFloatArray;
41 typedef nsTArray<float> AudioFloatArray;
42 
43 class PeriodicWave {
44  public:
45   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WebCore::PeriodicWave);
46 
47   static already_AddRefed<PeriodicWave> createSine(float sampleRate);
48   static already_AddRefed<PeriodicWave> createSquare(float sampleRate);
49   static already_AddRefed<PeriodicWave> createSawtooth(float sampleRate);
50   static already_AddRefed<PeriodicWave> createTriangle(float sampleRate);
51 
52   // Creates an arbitrary periodic wave given the frequency components
53   // (Fourier coefficients).
54   static already_AddRefed<PeriodicWave> create(float sampleRate,
55                                                const float* real,
56                                                const float* imag,
57                                                size_t numberOfComponents,
58                                                bool disableNormalization);
59 
60   // Returns pointers to the lower and higher wave data for the pitch range
61   // containing the given fundamental frequency. These two tables are in
62   // adjacent "pitch" ranges where the higher table will have the maximum
63   // number of partials which won't alias when played back at this
64   // fundamental frequency. The lower wave is the next range containing fewer
65   // partials than the higher wave. Interpolation between these two tables
66   // can be made according to tableInterpolationFactor. Where values
67   // from 0 -> 1 interpolate between lower -> higher.
68   void waveDataForFundamentalFrequency(float, float*& lowerWaveData,
69                                        float*& higherWaveData,
70                                        float& tableInterpolationFactor);
71 
72   // Returns the scalar multiplier to the oscillator frequency to calculate
73   // wave buffer phase increment.
rateScale()74   float rateScale() const { return m_rateScale; }
75 
periodicWaveSize()76   unsigned periodicWaveSize() const { return m_periodicWaveSize; }
sampleRate()77   float sampleRate() const { return m_sampleRate; }
78 
79   size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
80 
81  private:
82   explicit PeriodicWave(float sampleRate, size_t numberOfComponents,
83                         bool disableNormalization);
~PeriodicWave()84   ~PeriodicWave() {}
85 
86   void generateBasicWaveform(mozilla::dom::OscillatorType);
87 
88   float m_sampleRate;
89   unsigned m_periodicWaveSize;
90   unsigned m_numberOfRanges;
91   float m_centsPerRange;
92   unsigned m_numberOfComponents;
93   nsAutoPtr<AudioFloatArray> m_realComponents;
94   nsAutoPtr<AudioFloatArray> m_imagComponents;
95 
96   // The lowest frequency (in Hertz) where playback will include all of the
97   // partials.  Playing back lower than this frequency will gradually lose
98   // more high-frequency information.
99   // This frequency is quite low (~10Hz @ // 44.1KHz)
100   float m_lowestFundamentalFrequency;
101 
102   float m_rateScale;
103 
numberOfRanges()104   unsigned numberOfRanges() const { return m_numberOfRanges; }
105 
106   // Maximum possible number of partials (before culling).
107   unsigned maxNumberOfPartials() const;
108 
109   unsigned numberOfPartialsForRange(unsigned rangeIndex) const;
110 
111   // Creates table for specified index based on fundamental frequency.
112   void createBandLimitedTables(float fundamentalFrequency, unsigned rangeIndex);
113   unsigned m_maxPartialsInBandLimitedTable;
114   float m_normalizationScale;
115   bool m_disableNormalization;
116   nsTArray<nsAutoPtr<AlignedAudioFloatArray> > m_bandLimitedTables;
117 };
118 
119 }  // namespace WebCore
120 
121 #endif  // PeriodicWave_h
122