1/* 2 * Copyright (C) 2010, 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 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY 17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25#include "config.h" 26 27#if ENABLE(WEB_AUDIO) 28 29#include "modules/webaudio/BiquadProcessor.h" 30 31#include "modules/webaudio/BiquadDSPKernel.h" 32 33namespace blink { 34 35BiquadProcessor::BiquadProcessor(AudioContext* context, float sampleRate, size_t numberOfChannels, bool autoInitialize) 36 : AudioDSPKernelProcessor(sampleRate, numberOfChannels) 37 , m_type(LowPass) 38 , m_parameter1(nullptr) 39 , m_parameter2(nullptr) 40 , m_parameter3(nullptr) 41 , m_parameter4(nullptr) 42 , m_filterCoefficientsDirty(true) 43 , m_hasSampleAccurateValues(false) 44{ 45 // Create parameters for BiquadFilterNode. 46 m_parameter1 = AudioParam::create(context, 350.0); 47 m_parameter2 = AudioParam::create(context, 1); 48 m_parameter3 = AudioParam::create(context, 0.0); 49 m_parameter4 = AudioParam::create(context, 0.0); 50 51 if (autoInitialize) 52 initialize(); 53} 54 55BiquadProcessor::~BiquadProcessor() 56{ 57 if (isInitialized()) 58 uninitialize(); 59} 60 61void BiquadProcessor::trace(Visitor* visitor) 62{ 63 visitor->trace(m_parameter1); 64 visitor->trace(m_parameter2); 65 visitor->trace(m_parameter3); 66 visitor->trace(m_parameter4); 67 AudioDSPKernelProcessor::trace(visitor); 68} 69 70PassOwnPtr<AudioDSPKernel> BiquadProcessor::createKernel() 71{ 72 return adoptPtr(new BiquadDSPKernel(this)); 73} 74 75void BiquadProcessor::checkForDirtyCoefficients() 76{ 77 // Deal with smoothing / de-zippering. Start out assuming filter parameters are not changing. 78 79 // The BiquadDSPKernel objects rely on this value to see if they need to re-compute their internal filter coefficients. 80 m_filterCoefficientsDirty = false; 81 m_hasSampleAccurateValues = false; 82 83 if (m_parameter1->hasSampleAccurateValues() || m_parameter2->hasSampleAccurateValues() || m_parameter3->hasSampleAccurateValues() || m_parameter4->hasSampleAccurateValues()) { 84 m_filterCoefficientsDirty = true; 85 m_hasSampleAccurateValues = true; 86 } else { 87 if (m_hasJustReset) { 88 // Snap to exact values first time after reset, then smooth for subsequent changes. 89 m_parameter1->resetSmoothedValue(); 90 m_parameter2->resetSmoothedValue(); 91 m_parameter3->resetSmoothedValue(); 92 m_parameter4->resetSmoothedValue(); 93 m_filterCoefficientsDirty = true; 94 m_hasJustReset = false; 95 } else { 96 // Smooth all of the filter parameters. If they haven't yet converged to their target value then mark coefficients as dirty. 97 bool isStable1 = m_parameter1->smooth(); 98 bool isStable2 = m_parameter2->smooth(); 99 bool isStable3 = m_parameter3->smooth(); 100 bool isStable4 = m_parameter4->smooth(); 101 if (!(isStable1 && isStable2 && isStable3 && isStable4)) 102 m_filterCoefficientsDirty = true; 103 } 104 } 105} 106 107void BiquadProcessor::process(const AudioBus* source, AudioBus* destination, size_t framesToProcess) 108{ 109 if (!isInitialized()) { 110 destination->zero(); 111 return; 112 } 113 114 checkForDirtyCoefficients(); 115 116 // For each channel of our input, process using the corresponding BiquadDSPKernel into the output channel. 117 for (unsigned i = 0; i < m_kernels.size(); ++i) 118 m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess); 119} 120 121void BiquadProcessor::setType(FilterType type) 122{ 123 if (type != m_type) { 124 m_type = type; 125 reset(); // The filter state must be reset only if the type has changed. 126 } 127} 128 129void BiquadProcessor::getFrequencyResponse(int nFrequencies, 130 const float* frequencyHz, 131 float* magResponse, 132 float* phaseResponse) 133{ 134 // Compute the frequency response on a separate temporary kernel 135 // to avoid interfering with the processing running in the audio 136 // thread on the main kernels. 137 138 OwnPtr<BiquadDSPKernel> responseKernel = adoptPtr(new BiquadDSPKernel(this)); 139 140 responseKernel->getFrequencyResponse(nFrequencies, frequencyHz, magResponse, phaseResponse); 141} 142 143} // namespace blink 144 145#endif // ENABLE(WEB_AUDIO) 146