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 | |
33 | namespace WebCore { |
34 | |
35 | BiquadProcessor::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 | |
57 | BiquadProcessor::~BiquadProcessor() |
58 | { |
59 | if (isInitialized()) |
60 | uninitialize(); |
61 | } |
62 | |
63 | std::unique_ptr<AudioDSPKernel> BiquadProcessor::createKernel() |
64 | { |
65 | return std::make_unique<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(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 | |
122 | void 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 | |