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33 #include "platform/audio/HRTFDatabase.h"
40 const int HRTFDatabase::MinElevation = -45;
41 const int HRTFDatabase::MaxElevation = 90;
42 const unsigned HRTFDatabase::RawElevationAngleSpacing = 15;
43 const unsigned HRTFDatabase::NumberOfRawElevations = 10; // -45 -> +90 (each 15 degrees)
44 const unsigned HRTFDatabase::InterpolationFactor = 1;
45 const unsigned HRTFDatabase::NumberOfTotalElevations = NumberOfRawElevations * InterpolationFactor;
47 PassOwnPtr<HRTFDatabase> HRTFDatabase::create(float sampleRate)
49 OwnPtr<HRTFDatabase> hrtfDatabase = adoptPtr(new HRTFDatabase(sampleRate));
50 return hrtfDatabase.release();
53 HRTFDatabase::HRTFDatabase(float sampleRate)
54 : m_elevations(NumberOfTotalElevations)
55 , m_sampleRate(sampleRate)
57 unsigned elevationIndex = 0;
58 for (int elevation = MinElevation; elevation <= MaxElevation; elevation += RawElevationAngleSpacing) {
59 OwnPtr<HRTFElevation> hrtfElevation = HRTFElevation::createForSubject("Composite", elevation, sampleRate);
60 ASSERT(hrtfElevation.get());
61 if (!hrtfElevation.get())
64 m_elevations[elevationIndex] = hrtfElevation.release();
65 elevationIndex += InterpolationFactor;
68 // Now, go back and interpolate elevations.
69 if (InterpolationFactor > 1) {
70 for (unsigned i = 0; i < NumberOfTotalElevations; i += InterpolationFactor) {
71 unsigned j = (i + InterpolationFactor);
72 if (j >= NumberOfTotalElevations)
73 j = i; // for last elevation interpolate with itself
75 // Create the interpolated convolution kernels and delays.
76 for (unsigned jj = 1; jj < InterpolationFactor; ++jj) {
77 float x = static_cast<float>(jj) / static_cast<float>(InterpolationFactor);
78 m_elevations[i + jj] = HRTFElevation::createByInterpolatingSlices(m_elevations[i].get(), m_elevations[j].get(), x, sampleRate);
79 ASSERT(m_elevations[i + jj].get());
85 void HRTFDatabase::getKernelsFromAzimuthElevation(double azimuthBlend, unsigned azimuthIndex, double elevationAngle, HRTFKernel* &kernelL, HRTFKernel* &kernelR,
86 double& frameDelayL, double& frameDelayR)
88 unsigned elevationIndex = indexFromElevationAngle(elevationAngle);
89 ASSERT_WITH_SECURITY_IMPLICATION(elevationIndex < m_elevations.size() && m_elevations.size() > 0);
91 if (!m_elevations.size()) {
97 if (elevationIndex > m_elevations.size() - 1)
98 elevationIndex = m_elevations.size() - 1;
100 HRTFElevation* hrtfElevation = m_elevations[elevationIndex].get();
101 ASSERT(hrtfElevation);
102 if (!hrtfElevation) {
108 hrtfElevation->getKernelsFromAzimuth(azimuthBlend, azimuthIndex, kernelL, kernelR, frameDelayL, frameDelayR);
111 unsigned HRTFDatabase::indexFromElevationAngle(double elevationAngle)
113 // Clamp to allowed range.
114 elevationAngle = max(static_cast<double>(MinElevation), elevationAngle);
115 elevationAngle = min(static_cast<double>(MaxElevation), elevationAngle);
117 unsigned elevationIndex = static_cast<int>(InterpolationFactor * (elevationAngle - MinElevation) / RawElevationAngleSpacing);
118 return elevationIndex;
123 #endif // ENABLE(WEB_AUDIO)