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#ifndef BiquadProcessor_h
26#define BiquadProcessor_h
27
28#include "AudioDSPKernel.h"
29#include "AudioDSPKernelProcessor.h"
30#include "AudioNode.h"
31#include "AudioParam.h"
32#include "Biquad.h"
33#include <memory>
34#include <wtf/RefPtr.h>
35
36namespace WebCore {
37
38// BiquadProcessor is an AudioDSPKernelProcessor which uses Biquad objects to implement several common filters.
39
40class BiquadProcessor : public AudioDSPKernelProcessor {
41public:
42    enum FilterType {
43        LowPass = 0,
44        HighPass = 1,
45        BandPass = 2,
46        LowShelf = 3,
47        HighShelf = 4,
48        Peaking = 5,
49        Notch = 6,
50        Allpass = 7
51    };
52
53    BiquadProcessor(AudioContext*, float sampleRate, size_t numberOfChannels, bool autoInitialize);
54
55    virtual ~BiquadProcessor();
56
57    virtual std::unique_ptr<AudioDSPKernel> createKernel() override;
58
59    virtual void process(const AudioBus* source, AudioBus* destination, size_t framesToProcess) override;
60
61    // Get the magnitude and phase response of the filter at the given
62    // set of frequencies (in Hz). The phase response is in radians.
63    void getFrequencyResponse(int nFrequencies,
64                              const float* frequencyHz,
65                              float* magResponse,
66                              float* phaseResponse);
67
68    void checkForDirtyCoefficients();
69
70    bool filterCoefficientsDirty() const { return m_filterCoefficientsDirty; }
71    bool hasSampleAccurateValues() const { return m_hasSampleAccurateValues; }
72
73    AudioParam* parameter1() { return m_parameter1.get(); }
74    AudioParam* parameter2() { return m_parameter2.get(); }
75    AudioParam* parameter3() { return m_parameter3.get(); }
76    AudioParam* parameter4() { return m_parameter4.get(); }
77
78    FilterType type() const { return m_type; }
79    void setType(FilterType);
80
81private:
82    FilterType m_type;
83
84    RefPtr<AudioParam> m_parameter1;
85    RefPtr<AudioParam> m_parameter2;
86    RefPtr<AudioParam> m_parameter3;
87    RefPtr<AudioParam> m_parameter4;
88
89    // so DSP kernels know when to re-compute coefficients
90    bool m_filterCoefficientsDirty;
91
92    // Set to true if any of the filter parameters are sample-accurate.
93    bool m_hasSampleAccurateValues;
94};
95
96} // namespace WebCore
97
98#endif // BiquadProcessor_h
99