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
21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 "mozilla/UniquePtr.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 using mozilla::UniquePtr;
44 
45 class PeriodicWave {
46  public:
47   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WebCore::PeriodicWave);
48 
49   static already_AddRefed<PeriodicWave> createSine(float sampleRate);
50   static already_AddRefed<PeriodicWave> createSquare(float sampleRate);
51   static already_AddRefed<PeriodicWave> createSawtooth(float sampleRate);
52   static already_AddRefed<PeriodicWave> createTriangle(float sampleRate);
53 
54   // Creates an arbitrary periodic wave given the frequency components
55   // (Fourier coefficients).
56   static already_AddRefed<PeriodicWave> create(float sampleRate,
57                                                const float* real,
58                                                const float* imag,
59                                                size_t numberOfComponents,
60                                                bool disableNormalization);
61 
62   // Returns pointers to the lower and higher wave data for the pitch range
63   // containing the given fundamental frequency. These two tables are in
64   // adjacent "pitch" ranges where the higher table will have the maximum
65   // number of partials which won't alias when played back at this
66   // fundamental frequency. The lower wave is the next range containing fewer
67   // partials than the higher wave. Interpolation between these two tables
68   // can be made according to tableInterpolationFactor. Where values
69   // from 0 -> 1 interpolate between lower -> higher.
70   void waveDataForFundamentalFrequency(float, float*& lowerWaveData,
71                                        float*& higherWaveData,
72                                        float& tableInterpolationFactor);
73 
74   // Returns the scalar multiplier to the oscillator frequency to calculate
75   // wave buffer phase increment.
rateScale()76   float rateScale() const { return m_rateScale; }
77 
periodicWaveSize()78   unsigned periodicWaveSize() const { return m_periodicWaveSize; }
sampleRate()79   float sampleRate() const { return m_sampleRate; }
80 
81   size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
82 
83  private:
84   explicit PeriodicWave(float sampleRate, size_t numberOfComponents,
85                         bool disableNormalization);
86   ~PeriodicWave() = default;
87 
88   void generateBasicWaveform(mozilla::dom::OscillatorType);
89 
90   float m_sampleRate;
91   unsigned m_periodicWaveSize;
92   unsigned m_numberOfRanges;
93   float m_centsPerRange;
94   unsigned m_numberOfComponents;
95   UniquePtr<AudioFloatArray> m_realComponents;
96   UniquePtr<AudioFloatArray> m_imagComponents;
97 
98   // The lowest frequency (in Hertz) where playback will include all of the
99   // partials.  Playing back lower than this frequency will gradually lose
100   // more high-frequency information.
101   // This frequency is quite low (~10Hz @ // 44.1KHz)
102   float m_lowestFundamentalFrequency;
103 
104   float m_rateScale;
105 
numberOfRanges()106   unsigned numberOfRanges() const { return m_numberOfRanges; }
107 
108   // Maximum possible number of partials (before culling).
109   unsigned maxNumberOfPartials() const;
110 
111   unsigned numberOfPartialsForRange(unsigned rangeIndex) const;
112 
113   // Creates table for specified index based on fundamental frequency.
114   void createBandLimitedTables(float fundamentalFrequency, unsigned rangeIndex);
115   unsigned m_maxPartialsInBandLimitedTable;
116   float m_normalizationScale;
117   bool m_disableNormalization;
118   nsTArray<UniquePtr<AlignedAudioFloatArray> > m_bandLimitedTables;
119 };
120 
121 }  // namespace WebCore
122 
123 #endif  // PeriodicWave_h
124