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 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 "HRTFDatabase.h"
34
35#include "HRTFElevation.h"
36
37namespace WebCore {
38
39const int HRTFDatabase::MinElevation = -45;
40const int HRTFDatabase::MaxElevation = 90;
41const unsigned HRTFDatabase::RawElevationAngleSpacing = 15;
42const unsigned HRTFDatabase::NumberOfRawElevations = 10; // -45 -> +90 (each 15 degrees)
43const unsigned HRTFDatabase::InterpolationFactor = 1;
44const unsigned HRTFDatabase::NumberOfTotalElevations = NumberOfRawElevations * InterpolationFactor;
45
46HRTFDatabase::HRTFDatabase(float sampleRate)
47 : m_elevations(NumberOfTotalElevations)
48 , m_sampleRate(sampleRate)
49{
50 unsigned elevationIndex = 0;
51 for (int elevation = MinElevation; elevation <= MaxElevation; elevation += RawElevationAngleSpacing) {
52 std::unique_ptr<HRTFElevation> hrtfElevation = HRTFElevation::createForSubject("Composite", elevation, sampleRate);
53 ASSERT(hrtfElevation.get());
54 if (!hrtfElevation.get())
55 return;
56
57 m_elevations[elevationIndex] = WTFMove(hrtfElevation);
58 elevationIndex += InterpolationFactor;
59 }
60
61 // Now, go back and interpolate elevations.
62 if (InterpolationFactor > 1) {
63 for (unsigned i = 0; i < NumberOfTotalElevations; i += InterpolationFactor) {
64 unsigned j = (i + InterpolationFactor);
65 if (j >= NumberOfTotalElevations)
66 j = i; // for last elevation interpolate with itself
67
68 // Create the interpolated convolution kernels and delays.
69 for (unsigned jj = 1; jj < InterpolationFactor; ++jj) {
70 float x = static_cast<float>(jj) / static_cast<float>(InterpolationFactor);
71 m_elevations[i + jj] = HRTFElevation::createByInterpolatingSlices(m_elevations[i].get(), m_elevations[j].get(), x, sampleRate);
72 ASSERT(m_elevations[i + jj].get());
73 }
74 }
75 }
76}
77
78void HRTFDatabase::getKernelsFromAzimuthElevation(double azimuthBlend, unsigned azimuthIndex, double elevationAngle, HRTFKernel* &kernelL, HRTFKernel* &kernelR,
79 double& frameDelayL, double& frameDelayR)
80{
81 unsigned elevationIndex = indexFromElevationAngle(elevationAngle);
82 ASSERT_WITH_SECURITY_IMPLICATION(elevationIndex < m_elevations.size() && m_elevations.size() > 0);
83
84 if (!m_elevations.size()) {
85 kernelL = 0;
86 kernelR = 0;
87 return;
88 }
89
90 if (elevationIndex > m_elevations.size() - 1)
91 elevationIndex = m_elevations.size() - 1;
92
93 HRTFElevation* hrtfElevation = m_elevations[elevationIndex].get();
94 ASSERT(hrtfElevation);
95 if (!hrtfElevation) {
96 kernelL = 0;
97 kernelR = 0;
98 return;
99 }
100
101 hrtfElevation->getKernelsFromAzimuth(azimuthBlend, azimuthIndex, kernelL, kernelR, frameDelayL, frameDelayR);
102}
103
104unsigned HRTFDatabase::indexFromElevationAngle(double elevationAngle)
105{
106 // Clamp to allowed range.
107 elevationAngle = std::max(static_cast<double>(MinElevation), elevationAngle);
108 elevationAngle = std::min(static_cast<double>(MaxElevation), elevationAngle);
109
110 unsigned elevationIndex = static_cast<int>(InterpolationFactor * (elevationAngle - MinElevation) / RawElevationAngleSpacing);
111 return elevationIndex;
112}
113
114} // namespace WebCore
115
116#endif // ENABLE(WEB_AUDIO)
117