/* * 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 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. */ #pragma once #include "AudioArray.h" #include <memory> #include <runtime/Float32Array.h> #include <wtf/RefCounted.h> #include <wtf/Vector.h> namespace WebCore { class PeriodicWave : public RefCounted<PeriodicWave> { public: static Ref<PeriodicWave> createSine(float sampleRate); static Ref<PeriodicWave> createSquare(float sampleRate); static Ref<PeriodicWave> createSawtooth(float sampleRate); static Ref<PeriodicWave> createTriangle(float sampleRate); // Creates an arbitrary wave given the frequency components (Fourier coefficients). static Ref<PeriodicWave> create(float sampleRate, Float32Array& real, Float32Array& imag); // 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 table phase increment. float rateScale() const { return m_rateScale; } unsigned periodicWaveSize() const { return m_periodicWaveSize; } float sampleRate() const { return m_sampleRate; } private: enum class Type { Sine, Square, Sawtooth, Triangle, }; explicit PeriodicWave(float sampleRate); void generateBasicWaveform(Type); 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); Vector<std::unique_ptr<AudioFloatArray>> m_bandLimitedTables; }; } // namespace WebCore