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 33 namespace WebCore { 34 35 BiquadProcessor::BiquadProcessor(AudioContext* context, float sampleRate, size_t numberOfChannels, bool autoInitialize) 36 : AudioDSPKernelProcessor(sampleRate, numberOfChannels) 37 , m_type(LowPass) 38 , m_parameter1(0) 39 , m_parameter2(0) 40 , m_parameter3(0) 41 , m_parameter4(0) 42 , m_filterCoefficientsDirty(true) 43 , m_hasSampleAccurateValues(false) 44 { 45 double nyquist = 0.5 * this->sampleRate(); 46 47 // Create parameters for BiquadFilterNode. 48 m_parameter1 = AudioParam::create(context, "frequency", 350.0, 10.0, nyquist); 49 m_parameter2 = AudioParam::create(context, "Q", 1, 0.0001, 1000.0); 50 m_parameter3 = AudioParam::create(context, "gain", 0.0, -40, 40); 51 m_parameter4 = AudioParam::create(context, "detune", 0.0, -4800, 4800); 52 53 if (autoInitialize) 54 initialize(); 55 } 56 57 BiquadProcessor::~BiquadProcessor() 58 { 59 if (isInitialized()) 60 uninitialize(); 61 } 62 63 PassOwnPtr<AudioDSPKernel> BiquadProcessor::createKernel() 64 { 65 return adoptPtr(new BiquadDSPKernel(this)); 66 } 67 68 void BiquadProcessor::checkForDirtyCoefficients() 69 { 70 // Deal with smoothing / de-zippering. Start out assuming filter parameters are not changing. 71 72 // The BiquadDSPKernel objects rely on this value to see if they need to re-compute their internal filter coefficients. 73 m_filterCoefficientsDirty = false; 74 m_hasSampleAccurateValues = false; 75 76 if (m_parameter1->hasSampleAccurateValues() || m_parameter2->hasSampleAccurateValues() || m_parameter3->hasSampleAccurateValues() || m_parameter4->hasSampleAccurateValues()) { 77 m_filterCoefficientsDirty = true; 78 m_hasSampleAccurateValues = true; 79 } else { 80 if (m_hasJustReset) { 81 // Snap to exact values first time after reset, then smooth for subsequent changes. 82 m_parameter1->resetSmoothedValue(); 83 m_parameter2->resetSmoothedValue(); 84 m_parameter3->resetSmoothedValue(); 85 m_parameter4->resetSmoothedValue(); 86 m_filterCoefficientsDirty = true; 87 m_hasJustReset = false; 88 } else { 89 // Smooth all of the filter parameters. If they haven't yet converged to their target value then mark coefficients as dirty. 90 bool isStable1 = m_parameter1->smooth(); 91 bool isStable2 = m_parameter2->smooth(); 92 bool isStable3 = m_parameter3->smooth(); 93 bool isStable4 = m_parameter4->smooth(); 94 if (!(isStable1 && isStable2 && isStable3 && isStable4)) 95 m_filterCoefficientsDirty = true; 96 } 97 } 98 } 99 100 void BiquadProcessor::process(const AudioBus* source, AudioBus* destination, size_t framesToProcess) 101 { 102 if (!isInitialized()) { 103 destination->zero(); 104 return; 105 } 106 107 checkForDirtyCoefficients(); 108 109 // For each channel of our input, process using the corresponding BiquadDSPKernel into the output channel. 110 for (unsigned i = 0; i < m_kernels.size(); ++i) 111 m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess); 112 } 113 114 void BiquadProcessor::setType(FilterType type) 115 { 116 if (type != m_type) { 117 m_type = type; 118 reset(); // The filter state must be reset only if the type has changed. 119 } 120 } 121 122 void BiquadProcessor::getFrequencyResponse(int nFrequencies, 123 const float* frequencyHz, 124 float* magResponse, 125 float* phaseResponse) 126 { 127 // Compute the frequency response on a separate temporary kernel 128 // to avoid interfering with the processing running in the audio 129 // thread on the main kernels. 130 131 OwnPtr<BiquadDSPKernel> responseKernel = adoptPtr(new BiquadDSPKernel(this)); 132 133 responseKernel->getFrequencyResponse(nFrequencies, frequencyHz, magResponse, phaseResponse); 134 } 135 136 } // namespace WebCore 137 138 #endif // ENABLE(WEB_AUDIO) 139