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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 FFTFrame_h
30 #define FFTFrame_h
31 
32 #include "AudioArray.h"
33 
34 #if OS(DARWIN)
35 #include <Accelerate/Accelerate.h>
36 #endif
37 
38 #if !OS(DARWIN)
39 #if USE(WEBAUDIO_MKL)
40 #include "mkl_dfti.h"
41 #endif // USE(WEBAUDIO_MKL)
42 #if USE(WEBAUDIO_FFTW)
43 #include "fftw3.h"
44 #endif // USE(WEBAUDIO_FFTW)
45 #endif
46 
47 #include <wtf/PassOwnPtr.h>
48 #include <wtf/Platform.h>
49 #include <wtf/Threading.h>
50 
51 namespace WebCore {
52 
53 // Defines the interface for an "FFT frame", an object which is able to perform a forward
54 // and reverse FFT, internally storing the resultant frequency-domain data.
55 
56 class FFTFrame {
57 public:
58     // The constructors, destructor, and methods up to the CROSS-PLATFORM section have platform-dependent implementations.
59 
60     FFTFrame(unsigned fftSize);
61     FFTFrame(); // creates a blank/empty frame for later use with createInterpolatedFrame()
62     FFTFrame(const FFTFrame& frame);
63     ~FFTFrame();
64 
65     static void initialize();
66     static void cleanup();
67     void doFFT(float* data);
68     void doInverseFFT(float* data);
69     void multiply(const FFTFrame& frame); // multiplies ourself with frame : effectively operator*=()
70 
71     float* realData() const;
72     float* imagData() const;
73 
74     void print(); // for debugging
75 
76     // CROSS-PLATFORM
77     // The remaining public methods have cross-platform implementations:
78 
79     // Interpolates from frame1 -> frame2 as x goes from 0.0 -> 1.0
80     static PassOwnPtr<FFTFrame> createInterpolatedFrame(const FFTFrame& frame1, const FFTFrame& frame2, double x);
81 
82     void doPaddedFFT(float* data, size_t dataSize); // zero-padding with dataSize <= fftSize
83     double extractAverageGroupDelay();
84     void addConstantGroupDelay(double sampleFrameDelay);
85 
fftSize()86     unsigned fftSize() const { return m_FFTSize; }
log2FFTSize()87     unsigned log2FFTSize() const { return m_log2FFTSize; }
88 
89 private:
90     unsigned m_FFTSize;
91     unsigned m_log2FFTSize;
92 
93     void interpolateFrequencyComponents(const FFTFrame& frame1, const FFTFrame& frame2, double x);
94 
95 #if OS(DARWIN)
dspSplitComplex()96     DSPSplitComplex& dspSplitComplex() { return m_frame; }
dspSplitComplex()97     DSPSplitComplex dspSplitComplex() const { return m_frame; }
98 
99     static FFTSetup fftSetupForSize(unsigned fftSize);
100 
101     static FFTSetup* fftSetups;
102 
103     FFTSetup m_FFTSetup;
104 
105     DSPSplitComplex m_frame;
106     AudioFloatArray m_realData;
107     AudioFloatArray m_imagData;
108 #else // !OS(DARWIN)
109 #if USE(WEBAUDIO_MKL)
110     // Interleaves the planar real and imaginary data and returns a
111     // pointer to the resulting storage which can be used for in-place
112     // or out-of-place operations. FIXME: ideally all of the MKL
113     // routines would operate on planar data and this method would be
114     // removed.
115     float* getUpToDateComplexData();
116 
117     static DFTI_DESCRIPTOR_HANDLE descriptorHandleForSize(unsigned fftSize);
118 
119     static DFTI_DESCRIPTOR_HANDLE* descriptorHandles;
120 
121     DFTI_DESCRIPTOR_HANDLE m_handle;
122     AudioFloatArray m_complexData;
123     AudioFloatArray m_realData;
124     AudioFloatArray m_imagData;
125 #endif // USE(WEBAUDIO_MKL)
126 #if USE(WEBAUDIO_FFTW)
127     fftwf_plan m_forwardPlan;
128     fftwf_plan m_backwardPlan;
129 
130     enum Direction {
131         Forward,
132         Backward
133     };
134 
135     // Both the real and imaginary data are stored here.
136     // The real data is stored first, followed by three float values of padding.
137     // The imaginary data is stored after the padding and is 16-byte aligned (if m_data itself is aligned).
138     // The reason we don't use separate arrays for real and imaginary is because the FFTW plans are shared
139     // between FFTFrame instances and require that the real and imaginary data pointers be the same distance apart.
140     AudioFloatArray m_data;
141 
142     static Mutex *s_planLock;
143     static fftwf_plan* fftwForwardPlans;
144     static fftwf_plan* fftwBackwardPlans;
145 
146     static fftwf_plan fftwPlanForSize(unsigned fftSize, Direction,
147                                       float*, float*, float*);
148 #endif // USE(WEBAUDIO_FFTW)
149 #endif // !OS(DARWIN)
150 };
151 
152 } // namespace WebCore
153 
154 #endif // FFTFrame_h
155