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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 
     86     unsigned fftSize() const { return m_FFTSize; }
     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)
     96     DSPSplitComplex& dspSplitComplex() { return m_frame; }
     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