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