content/media/webaudio/blink/HRTFKernel.h

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TOR_BUG_9701
changeset 13
44a2da4a2ab2
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-1:000000000000 0:9b73a3c6ebb5
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 #ifndef HRTFKernel_h
30 #define HRTFKernel_h
31
32 #include "nsAutoPtr.h"
33 #include "nsAutoRef.h"
34 #include "nsTArray.h"
35 #include "mozilla/FFTBlock.h"
36 #include "mozilla/MemoryReporting.h"
37
38 namespace WebCore {
39
40 using mozilla::FFTBlock;
41
42 // HRTF stands for Head-Related Transfer Function.
43 // HRTFKernel is a frequency-domain representation of an impulse-response used as part of the spatialized panning system.
44 // For a given azimuth / elevation angle there will be one HRTFKernel for the left ear transfer function, and one for the right ear.
45 // The leading delay (average group delay) for each impulse response is extracted:
46 // m_fftFrame is the frequency-domain representation of the impulse response with the delay removed
47 // m_frameDelay is the leading delay of the original impulse response.
48 class HRTFKernel {
49 public:
50 // Note: this is destructive on the passed in |impulseResponse|.
51 // The |length| of |impulseResponse| must be a power of two.
52 // The size of the DFT will be |2 * length|.
53 static nsReturnRef<HRTFKernel> create(float* impulseResponse, size_t length, float sampleRate);
54
55 static nsReturnRef<HRTFKernel> create(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate);
56
57 // Given two HRTFKernels, and an interpolation factor x: 0 -> 1, returns an interpolated HRTFKernel.
58 static nsReturnRef<HRTFKernel> createInterpolatedKernel(HRTFKernel* kernel1, HRTFKernel* kernel2, float x);
59
60 FFTBlock* fftFrame() { return m_fftFrame.get(); }
61
62 size_t fftSize() const { return m_fftFrame->FFTSize(); }
63 float frameDelay() const { return m_frameDelay; }
64
65 float sampleRate() const { return m_sampleRate; }
66 double nyquist() const { return 0.5 * sampleRate(); }
67
68 size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
69 {
70 size_t amount = aMallocSizeOf(this);
71 amount += m_fftFrame->SizeOfIncludingThis(aMallocSizeOf);
72 return amount;
73 }
74
75 private:
76 HRTFKernel(const HRTFKernel& other) MOZ_DELETE;
77 void operator=(const HRTFKernel& other) MOZ_DELETE;
78
79 // Note: this is destructive on the passed in |impulseResponse|.
80 HRTFKernel(float* impulseResponse, size_t fftSize, float sampleRate);
81
82 HRTFKernel(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate)
83 : m_fftFrame(fftFrame)
84 , m_frameDelay(frameDelay)
85 , m_sampleRate(sampleRate)
86 {
87 }
88
89 nsAutoPtr<FFTBlock> m_fftFrame;
90 float m_frameDelay;
91 float m_sampleRate;
92 };
93
94 typedef nsTArray<nsAutoRef<HRTFKernel> > HRTFKernelList;
95
96 } // namespace WebCore
97
98 template <>
99 class nsAutoRefTraits<WebCore::HRTFKernel> :
100 public nsPointerRefTraits<WebCore::HRTFKernel> {
101 public:
102 static void Release(WebCore::HRTFKernel* ptr) { delete(ptr); }
103 };
104
105 namespace WebCore {
106
107 inline nsReturnRef<HRTFKernel> HRTFKernel::create(float* impulseResponse, size_t length, float sampleRate)
108 {
109 return nsReturnRef<HRTFKernel>(new HRTFKernel(impulseResponse, length, sampleRate));
110 }
111
112 inline nsReturnRef<HRTFKernel> HRTFKernel::create(nsAutoPtr<FFTBlock> fftFrame, float frameDelay, float sampleRate)
113 {
114 return nsReturnRef<HRTFKernel>(new HRTFKernel(fftFrame, frameDelay, sampleRate));
115 }
116
117 } // namespace WebCore
118 #endif // HRTFKernel_h

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