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 "platform/audio/AudioDSPKernel.h" 29 #include "platform/audio/AudioDSPKernelProcessor.h" 30 #include "platform/audio/Biquad.h" 31 #include "modules/webaudio/AudioNode.h" 32 #include "modules/webaudio/AudioParam.h" 33 #include "wtf/RefPtr.h" 34 35 namespace blink { 36 37 // BiquadProcessor is an AudioDSPKernelProcessor which uses Biquad objects to implement several common filters. 38 39 class BiquadProcessor FINAL : public AudioDSPKernelProcessor { 40 public: 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 virtual ~BiquadProcessor(); 54 virtual void trace(Visitor*) OVERRIDE; 55 56 virtual PassOwnPtr<AudioDSPKernel> createKernel() OVERRIDE; 57 58 virtual void process(const AudioBus* source, AudioBus* destination, size_t framesToProcess) OVERRIDE; 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 80 private: 81 FilterType m_type; 82 83 Member<AudioParam> m_parameter1; 84 Member<AudioParam> m_parameter2; 85 Member<AudioParam> m_parameter3; 86 Member<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 blink 96 97 #endif // BiquadProcessor_h 98