зеркало из https://github.com/mozilla/gecko-dev.git
Bug 865256 - Part 3c: Import blink's PeriodicWave. r=ehsan
From 3807300c75ae70f004b76cbce023e59a0367e09b Mon Sep 17 00:00:00 2001 This is the original code from blink svn trunk r157670 for reference. This commit has no porting or build support, to make subsequent changes easier to identify.
This commit is contained in:
Ralph Giles
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7a01f0d203
Коммит
bd65ff7b49
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/*
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* Copyright (C) 2012 Google Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
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* its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "config.h"
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#if ENABLE(WEB_AUDIO)
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#include "modules/webaudio/PeriodicWave.h"
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#include "core/platform/audio/FFTFrame.h"
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#include "core/platform/audio/VectorMath.h"
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#include "modules/webaudio/OscillatorNode.h"
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#include "wtf/OwnPtr.h"
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#include <algorithm>
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const unsigned PeriodicWaveSize = 4096; // This must be a power of two.
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const unsigned NumberOfRanges = 36; // There should be 3 * log2(PeriodicWaveSize) 1/3 octave ranges.
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const float CentsPerRange = 1200 / 3; // 1/3 Octave.
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namespace WebCore {
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using namespace VectorMath;
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PassRefPtr<PeriodicWave> PeriodicWave::create(float sampleRate, Float32Array* real, Float32Array* imag)
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{
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bool isGood = real && imag && real->length() == imag->length();
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ASSERT(isGood);
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if (isGood) {
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RefPtr<PeriodicWave> periodicWave = adoptRef(new PeriodicWave(sampleRate));
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size_t numberOfComponents = real->length();
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periodicWave->createBandLimitedTables(real->data(), imag->data(), numberOfComponents);
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return periodicWave;
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}
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return 0;
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}
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PassRefPtr<PeriodicWave> PeriodicWave::createSine(float sampleRate)
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{
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RefPtr<PeriodicWave> periodicWave = adoptRef(new PeriodicWave(sampleRate));
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periodicWave->generateBasicWaveform(OscillatorNode::SINE);
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return periodicWave;
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}
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PassRefPtr<PeriodicWave> PeriodicWave::createSquare(float sampleRate)
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{
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RefPtr<PeriodicWave> periodicWave = adoptRef(new PeriodicWave(sampleRate));
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periodicWave->generateBasicWaveform(OscillatorNode::SQUARE);
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return periodicWave;
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}
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PassRefPtr<PeriodicWave> PeriodicWave::createSawtooth(float sampleRate)
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{
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RefPtr<PeriodicWave> periodicWave = adoptRef(new PeriodicWave(sampleRate));
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periodicWave->generateBasicWaveform(OscillatorNode::SAWTOOTH);
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return periodicWave;
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}
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PassRefPtr<PeriodicWave> PeriodicWave::createTriangle(float sampleRate)
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{
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RefPtr<PeriodicWave> periodicWave = adoptRef(new PeriodicWave(sampleRate));
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periodicWave->generateBasicWaveform(OscillatorNode::TRIANGLE);
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return periodicWave;
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}
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PeriodicWave::PeriodicWave(float sampleRate)
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: m_sampleRate(sampleRate)
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, m_periodicWaveSize(PeriodicWaveSize)
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, m_numberOfRanges(NumberOfRanges)
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, m_centsPerRange(CentsPerRange)
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{
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ScriptWrappable::init(this);
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float nyquist = 0.5 * m_sampleRate;
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m_lowestFundamentalFrequency = nyquist / maxNumberOfPartials();
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m_rateScale = m_periodicWaveSize / m_sampleRate;
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}
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void PeriodicWave::waveDataForFundamentalFrequency(float fundamentalFrequency, float* &lowerWaveData, float* &higherWaveData, float& tableInterpolationFactor)
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{
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// Negative frequencies are allowed, in which case we alias to the positive frequency.
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fundamentalFrequency = fabsf(fundamentalFrequency);
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// Calculate the pitch range.
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float ratio = fundamentalFrequency > 0 ? fundamentalFrequency / m_lowestFundamentalFrequency : 0.5;
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float centsAboveLowestFrequency = log2f(ratio) * 1200;
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// Add one to round-up to the next range just in time to truncate partials before aliasing occurs.
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float pitchRange = 1 + centsAboveLowestFrequency / m_centsPerRange;
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pitchRange = std::max(pitchRange, 0.0f);
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pitchRange = std::min(pitchRange, static_cast<float>(m_numberOfRanges - 1));
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// The words "lower" and "higher" refer to the table data having the lower and higher numbers of partials.
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// It's a little confusing since the range index gets larger the more partials we cull out.
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// So the lower table data will have a larger range index.
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unsigned rangeIndex1 = static_cast<unsigned>(pitchRange);
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unsigned rangeIndex2 = rangeIndex1 < m_numberOfRanges - 1 ? rangeIndex1 + 1 : rangeIndex1;
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lowerWaveData = m_bandLimitedTables[rangeIndex2]->data();
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higherWaveData = m_bandLimitedTables[rangeIndex1]->data();
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// Ranges from 0 -> 1 to interpolate between lower -> higher.
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tableInterpolationFactor = pitchRange - rangeIndex1;
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}
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unsigned PeriodicWave::maxNumberOfPartials() const
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{
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return m_periodicWaveSize / 2;
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}
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unsigned PeriodicWave::numberOfPartialsForRange(unsigned rangeIndex) const
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{
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// Number of cents below nyquist where we cull partials.
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float centsToCull = rangeIndex * m_centsPerRange;
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// A value from 0 -> 1 representing what fraction of the partials to keep.
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float cullingScale = pow(2, -centsToCull / 1200);
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// The very top range will have all the partials culled.
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unsigned numberOfPartials = cullingScale * maxNumberOfPartials();
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return numberOfPartials;
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}
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// Convert into time-domain wave buffers.
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// One table is created for each range for non-aliasing playback at different playback rates.
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// Thus, higher ranges have more high-frequency partials culled out.
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void PeriodicWave::createBandLimitedTables(const float* realData, const float* imagData, unsigned numberOfComponents)
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{
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float normalizationScale = 1;
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unsigned fftSize = m_periodicWaveSize;
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unsigned halfSize = fftSize / 2;
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unsigned i;
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numberOfComponents = std::min(numberOfComponents, halfSize);
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m_bandLimitedTables.reserveCapacity(m_numberOfRanges);
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for (unsigned rangeIndex = 0; rangeIndex < m_numberOfRanges; ++rangeIndex) {
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// This FFTFrame is used to cull partials (represented by frequency bins).
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FFTFrame frame(fftSize);
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float* realP = frame.realData();
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float* imagP = frame.imagData();
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// Copy from loaded frequency data and scale.
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float scale = fftSize;
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vsmul(realData, 1, &scale, realP, 1, numberOfComponents);
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vsmul(imagData, 1, &scale, imagP, 1, numberOfComponents);
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// If fewer components were provided than 1/2 FFT size, then clear the remaining bins.
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for (i = numberOfComponents; i < halfSize; ++i) {
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realP[i] = 0;
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imagP[i] = 0;
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}
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// Generate complex conjugate because of the way the inverse FFT is defined.
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float minusOne = -1;
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vsmul(imagP, 1, &minusOne, imagP, 1, halfSize);
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// Find the starting bin where we should start culling.
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// We need to clear out the highest frequencies to band-limit the waveform.
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unsigned numberOfPartials = numberOfPartialsForRange(rangeIndex);
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// Cull the aliasing partials for this pitch range.
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for (i = numberOfPartials + 1; i < halfSize; ++i) {
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realP[i] = 0;
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imagP[i] = 0;
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}
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// Clear packed-nyquist if necessary.
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if (numberOfPartials < halfSize)
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imagP[0] = 0;
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// Clear any DC-offset.
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realP[0] = 0;
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// Create the band-limited table.
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OwnPtr<AudioFloatArray> table = adoptPtr(new AudioFloatArray(m_periodicWaveSize));
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m_bandLimitedTables.append(table.release());
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// Apply an inverse FFT to generate the time-domain table data.
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float* data = m_bandLimitedTables[rangeIndex]->data();
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frame.doInverseFFT(data);
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// For the first range (which has the highest power), calculate its peak value then compute normalization scale.
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if (!rangeIndex) {
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float maxValue;
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vmaxmgv(data, 1, &maxValue, m_periodicWaveSize);
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if (maxValue)
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normalizationScale = 1.0f / maxValue;
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}
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// Apply normalization scale.
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vsmul(data, 1, &normalizationScale, data, 1, m_periodicWaveSize);
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}
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}
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void PeriodicWave::generateBasicWaveform(int shape)
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{
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unsigned fftSize = periodicWaveSize();
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unsigned halfSize = fftSize / 2;
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AudioFloatArray real(halfSize);
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AudioFloatArray imag(halfSize);
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float* realP = real.data();
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float* imagP = imag.data();
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// Clear DC and Nyquist.
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realP[0] = 0;
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imagP[0] = 0;
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for (unsigned n = 1; n < halfSize; ++n) {
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float omega = 2 * piFloat * n;
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float invOmega = 1 / omega;
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// Fourier coefficients according to standard definition.
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float a; // Coefficient for cos().
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float b; // Coefficient for sin().
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// Calculate Fourier coefficients depending on the shape.
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// Note that the overall scaling (magnitude) of the waveforms is normalized in createBandLimitedTables().
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switch (shape) {
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case OscillatorNode::SINE:
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// Standard sine wave function.
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a = 0;
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b = (n == 1) ? 1 : 0;
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break;
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case OscillatorNode::SQUARE:
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// Square-shaped waveform with the first half its maximum value and the second half its minimum value.
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a = 0;
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b = invOmega * ((n & 1) ? 2 : 0);
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break;
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case OscillatorNode::SAWTOOTH:
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// Sawtooth-shaped waveform with the first half ramping from zero to maximum and the second half from minimum to zero.
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a = 0;
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b = -invOmega * cos(0.5 * omega);
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break;
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case OscillatorNode::TRIANGLE:
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// Triangle-shaped waveform going from its maximum value to its minimum value then back to the maximum value.
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a = (4 - 4 * cos(0.5 * omega)) / (n * n * piFloat * piFloat);
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b = 0;
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break;
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default:
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ASSERT_NOT_REACHED();
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a = 0;
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b = 0;
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break;
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}
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realP[n] = a;
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imagP[n] = b;
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}
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createBandLimitedTables(realP, imagP, halfSize);
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}
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} // namespace WebCore
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#endif // ENABLE(WEB_AUDIO)
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@ -0,0 +1,98 @@
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/*
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* Copyright (C) 2012 Google Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
|
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
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* its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||||
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
|
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef PeriodicWave_h
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#define PeriodicWave_h
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#include "bindings/v8/ScriptWrappable.h"
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#include "core/platform/audio/AudioArray.h"
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#include "wtf/Float32Array.h"
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#include "wtf/OwnPtr.h"
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#include "wtf/PassRefPtr.h"
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#include "wtf/RefCounted.h"
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#include "wtf/RefPtr.h"
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#include "wtf/Vector.h"
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namespace WebCore {
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class PeriodicWave : public ScriptWrappable, public RefCounted<PeriodicWave> {
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public:
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static PassRefPtr<PeriodicWave> createSine(float sampleRate);
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static PassRefPtr<PeriodicWave> createSquare(float sampleRate);
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static PassRefPtr<PeriodicWave> createSawtooth(float sampleRate);
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static PassRefPtr<PeriodicWave> createTriangle(float sampleRate);
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// Creates an arbitrary periodic wave given the frequency components (Fourier coefficients).
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static PassRefPtr<PeriodicWave> create(float sampleRate, Float32Array* real, Float32Array* imag);
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// Returns pointers to the lower and higher wave data for the pitch range containing
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// the given fundamental frequency. These two tables are in adjacent "pitch" ranges
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// where the higher table will have the maximum number of partials which won't alias when played back
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// at this fundamental frequency. The lower wave is the next range containing fewer partials than the higher wave.
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// Interpolation between these two tables can be made according to tableInterpolationFactor.
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// Where values from 0 -> 1 interpolate between lower -> higher.
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void waveDataForFundamentalFrequency(float, float* &lowerWaveData, float* &higherWaveData, float& tableInterpolationFactor);
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// Returns the scalar multiplier to the oscillator frequency to calculate wave buffer phase increment.
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float rateScale() const { return m_rateScale; }
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unsigned periodicWaveSize() const { return m_periodicWaveSize; }
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float sampleRate() const { return m_sampleRate; }
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private:
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explicit PeriodicWave(float sampleRate);
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void generateBasicWaveform(int);
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float m_sampleRate;
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unsigned m_periodicWaveSize;
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unsigned m_numberOfRanges;
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float m_centsPerRange;
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// The lowest frequency (in Hertz) where playback will include all of the partials.
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// Playing back lower than this frequency will gradually lose more high-frequency information.
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// This frequency is quite low (~10Hz @ 44.1KHz)
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float m_lowestFundamentalFrequency;
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float m_rateScale;
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unsigned numberOfRanges() const { return m_numberOfRanges; }
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// Maximum possible number of partials (before culling).
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unsigned maxNumberOfPartials() const;
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unsigned numberOfPartialsForRange(unsigned rangeIndex) const;
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// Creates tables based on numberOfComponents Fourier coefficients.
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void createBandLimitedTables(const float* real, const float* imag, unsigned numberOfComponents);
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Vector<OwnPtr<AudioFloatArray> > m_bandLimitedTables;
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};
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} // namespace WebCore
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#endif // PeriodicWave_h
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