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 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 14 * its contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include "config.h" 30 31#if ENABLE(WEB_AUDIO) 32 33#include "platform/audio/HRTFDatabase.h" 34 35namespace blink { 36 37const int HRTFDatabase::MinElevation = -45; 38const int HRTFDatabase::MaxElevation = 90; 39const unsigned HRTFDatabase::RawElevationAngleSpacing = 15; 40const unsigned HRTFDatabase::NumberOfRawElevations = 10; // -45 -> +90 (each 15 degrees) 41const unsigned HRTFDatabase::InterpolationFactor = 1; 42const unsigned HRTFDatabase::NumberOfTotalElevations = NumberOfRawElevations * InterpolationFactor; 43 44PassOwnPtr<HRTFDatabase> HRTFDatabase::create(float sampleRate) 45{ 46 OwnPtr<HRTFDatabase> hrtfDatabase = adoptPtr(new HRTFDatabase(sampleRate)); 47 return hrtfDatabase.release(); 48} 49 50HRTFDatabase::HRTFDatabase(float sampleRate) 51 : m_elevations(NumberOfTotalElevations) 52 , m_sampleRate(sampleRate) 53{ 54 unsigned elevationIndex = 0; 55 for (int elevation = MinElevation; elevation <= MaxElevation; elevation += RawElevationAngleSpacing) { 56 OwnPtr<HRTFElevation> hrtfElevation = HRTFElevation::createForSubject("Composite", elevation, sampleRate); 57 ASSERT(hrtfElevation.get()); 58 if (!hrtfElevation.get()) 59 return; 60 61 m_elevations[elevationIndex] = hrtfElevation.release(); 62 elevationIndex += InterpolationFactor; 63 } 64 65 // Now, go back and interpolate elevations. 66 if (InterpolationFactor > 1) { 67 for (unsigned i = 0; i < NumberOfTotalElevations; i += InterpolationFactor) { 68 unsigned j = (i + InterpolationFactor); 69 if (j >= NumberOfTotalElevations) 70 j = i; // for last elevation interpolate with itself 71 72 // Create the interpolated convolution kernels and delays. 73 for (unsigned jj = 1; jj < InterpolationFactor; ++jj) { 74 float x = static_cast<float>(jj) / static_cast<float>(InterpolationFactor); 75 m_elevations[i + jj] = HRTFElevation::createByInterpolatingSlices(m_elevations[i].get(), m_elevations[j].get(), x, sampleRate); 76 ASSERT(m_elevations[i + jj].get()); 77 } 78 } 79 } 80} 81 82void HRTFDatabase::getKernelsFromAzimuthElevation(double azimuthBlend, unsigned azimuthIndex, double elevationAngle, HRTFKernel* &kernelL, HRTFKernel* &kernelR, 83 double& frameDelayL, double& frameDelayR) 84{ 85 unsigned elevationIndex = indexFromElevationAngle(elevationAngle); 86 ASSERT_WITH_SECURITY_IMPLICATION(elevationIndex < m_elevations.size() && m_elevations.size() > 0); 87 88 if (!m_elevations.size()) { 89 kernelL = 0; 90 kernelR = 0; 91 return; 92 } 93 94 if (elevationIndex > m_elevations.size() - 1) 95 elevationIndex = m_elevations.size() - 1; 96 97 HRTFElevation* hrtfElevation = m_elevations[elevationIndex].get(); 98 ASSERT(hrtfElevation); 99 if (!hrtfElevation) { 100 kernelL = 0; 101 kernelR = 0; 102 return; 103 } 104 105 hrtfElevation->getKernelsFromAzimuth(azimuthBlend, azimuthIndex, kernelL, kernelR, frameDelayL, frameDelayR); 106} 107 108unsigned HRTFDatabase::indexFromElevationAngle(double elevationAngle) 109{ 110 // Clamp to allowed range. 111 elevationAngle = std::max(static_cast<double>(MinElevation), elevationAngle); 112 elevationAngle = std::min(static_cast<double>(MaxElevation), elevationAngle); 113 114 unsigned elevationIndex = static_cast<int>(InterpolationFactor * (elevationAngle - MinElevation) / RawElevationAngleSpacing); 115 return elevationIndex; 116} 117 118} // namespace blink 119 120#endif // ENABLE(WEB_AUDIO) 121