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 HRTFPanner_h 26 #define HRTFPanner_h 27 28 #include "DelayDSPKernel.h" 29 #include "FFTConvolver.h" 30 #include "Panner.h" 31 32 namespace WebCore { 33 34 class HRTFPanner : public Panner { 35 public: 36 explicit HRTFPanner(double sampleRate); 37 virtual ~HRTFPanner(); 38 39 // Panner 40 virtual void pan(double azimuth, double elevation, AudioBus* inputBus, AudioBus* outputBus, size_t framesToProcess); 41 virtual void reset(); 42 43 size_t fftSize() { return fftSizeForSampleRate(m_sampleRate); } 44 static size_t fftSizeForSampleRate(double sampleRate); 45 46 double sampleRate() const { return m_sampleRate; } 47 48 private: 49 // Given an azimuth angle in the range -180 -> +180, returns the corresponding azimuth index for the database, 50 // and azimuthBlend which is an interpolation value from 0 -> 1. 51 int calculateDesiredAzimuthIndexAndBlend(double azimuth, double& azimuthBlend); 52 53 double m_sampleRate; 54 55 // m_isFirstRender and m_azimuthIndex are used to avoid harshly changing from rendering at one azimuth angle to another angle very far away. 56 // Changing the azimuth gradually produces a smoother sound. 57 bool m_isFirstRender; 58 int m_azimuthIndex; 59 60 FFTConvolver m_convolverL; 61 FFTConvolver m_convolverR; 62 DelayDSPKernel m_delayLineL; 63 DelayDSPKernel m_delayLineR; 64 }; 65 66 } // namespace WebCore 67 68 #endif // HRTFPanner_h 69
