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 "BiquadProcessor.h"
30
31#include "BiquadDSPKernel.h"
32
33namespace WebCore {
34
35BiquadProcessor::BiquadProcessor(AudioContext& context, float sampleRate, size_t numberOfChannels, bool autoInitialize)
36 : AudioDSPKernelProcessor(sampleRate, numberOfChannels)
37 , m_type(BiquadFilterType::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
57BiquadProcessor::~BiquadProcessor()
58{
59 if (isInitialized())
60 uninitialize();
61}
62
63std::unique_ptr<AudioDSPKernel> BiquadProcessor::createKernel()
64{
65 return std::make_unique<BiquadDSPKernel>(this);
66}
67
68void 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
100void 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
114void BiquadProcessor::setType(BiquadFilterType 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
122void BiquadProcessor::getFrequencyResponse(int nFrequencies, const float* frequencyHz, float* magResponse, float* phaseResponse)
123{
124 // Compute the frequency response on a separate temporary kernel
125 // to avoid interfering with the processing running in the audio
126 // thread on the main kernels.
127
128 auto responseKernel = std::make_unique<BiquadDSPKernel>(this);
129
130 responseKernel->getFrequencyResponse(nFrequencies, frequencyHz, magResponse, phaseResponse);
131}
132
133} // namespace WebCore
134
135#endif // ENABLE(WEB_AUDIO)
136