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 blink {
34
BiquadProcessor(AudioContext * context,float sampleRate,size_t numberOfChannels,bool autoInitialize)35 BiquadProcessor::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
~BiquadProcessor()55 BiquadProcessor::~BiquadProcessor()
56 {
57 if (isInitialized())
58 uninitialize();
59 }
60
trace(Visitor * visitor)61 void 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
createKernel()70 PassOwnPtr<AudioDSPKernel> BiquadProcessor::createKernel()
71 {
72 return adoptPtr(new BiquadDSPKernel(this));
73 }
74
checkForDirtyCoefficients()75 void 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
process(const AudioBus * source,AudioBus * destination,size_t framesToProcess)107 void 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
setType(FilterType type)121 void 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
getFrequencyResponse(int nFrequencies,const float * frequencyHz,float * magResponse,float * phaseResponse)129 void 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