root/Source/platform/audio/FFTFrame.h

INCLUDED FROM

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#ifndef FFTFrame_h
#define FFTFrame_h

#include "platform/PlatformExport.h"
#include "platform/audio/AudioArray.h"

#if OS(MACOSX)
#include <Accelerate/Accelerate.h>
#elif USE(WEBAUDIO_OPENMAX_DL_FFT)
#include <dl/sp/api/omxSP.h>
#elif USE(WEBAUDIO_FFMPEG)
struct RDFTContext;
#endif

#if USE(WEBAUDIO_IPP)
#include <ipps.h>
#endif // USE(WEBAUDIO_IPP)

#include "wtf/Forward.h"
#include "wtf/PassOwnPtr.h"
#include "wtf/Threading.h"

namespace WebCore {

// Defines the interface for an "FFT frame", an object which is able to perform a forward
// and reverse FFT, internally storing the resultant frequency-domain data.

class PLATFORM_EXPORT FFTFrame {
public:
    // The constructors, destructor, and methods up to the CROSS-PLATFORM section have platform-dependent implementations.

    FFTFrame(unsigned fftSize);
    FFTFrame(); // creates a blank/empty frame for later use with createInterpolatedFrame()
    FFTFrame(const FFTFrame& frame);
    ~FFTFrame();

    static void initialize();
    static void cleanup();
    void doFFT(const float* data);
    void doInverseFFT(float* data);

    float* realData() const;
    float* imagData() const;

    void print(); // for debugging

    // CROSS-PLATFORM
    // The remaining public methods have cross-platform implementations:

    // Interpolates from frame1 -> frame2 as x goes from 0.0 -> 1.0
    static PassOwnPtr<FFTFrame> createInterpolatedFrame(const FFTFrame& frame1, const FFTFrame& frame2, double x);

    void doPaddedFFT(const float* data, size_t dataSize); // zero-padding with dataSize <= fftSize
    double extractAverageGroupDelay();
    void addConstantGroupDelay(double sampleFrameDelay);
    void multiply(const FFTFrame&); // multiplies ourself with frame : effectively operator*=()

    unsigned fftSize() const { return m_FFTSize; }
    unsigned log2FFTSize() const { return m_log2FFTSize; }

private:
    unsigned m_FFTSize;
    unsigned m_log2FFTSize;

    void interpolateFrequencyComponents(const FFTFrame& frame1, const FFTFrame& frame2, double x);

#if OS(MACOSX)
    DSPSplitComplex& dspSplitComplex() { return m_frame; }
    DSPSplitComplex dspSplitComplex() const { return m_frame; }

    static FFTSetup fftSetupForSize(unsigned fftSize);

    static FFTSetup* fftSetups;

    FFTSetup m_FFTSetup;

    DSPSplitComplex m_frame;
    AudioFloatArray m_realData;
    AudioFloatArray m_imagData;
#else // !OS(MACOSX)

#if USE(WEBAUDIO_FFMPEG)
    static RDFTContext* contextForSize(unsigned fftSize, int trans);

    RDFTContext* m_forwardContext;
    RDFTContext* m_inverseContext;

    float* getUpToDateComplexData();
    AudioFloatArray m_complexData;
    AudioFloatArray m_realData;
    AudioFloatArray m_imagData;
#endif // USE(WEBAUDIO_FFMPEG)

#if USE(WEBAUDIO_IPP)
    Ipp8u* m_buffer;
    IppsDFTSpec_R_32f* m_DFTSpec;

    float* getUpToDateComplexData();
    AudioFloatArray m_complexData;
    AudioFloatArray m_realData;
    AudioFloatArray m_imagData;
#endif // USE(WEBAUDIO_IPP)

#if USE(WEBAUDIO_OPENMAX_DL_FFT)
    static OMXFFTSpec_R_F32* contextForSize(unsigned log2FFTSize);

    OMXFFTSpec_R_F32* m_forwardContext;
    OMXFFTSpec_R_F32* m_inverseContext;

    AudioFloatArray m_complexData;
    AudioFloatArray m_realData;
    AudioFloatArray m_imagData;
#endif

#endif // !OS(MACOSX)
};

} // namespace WebCore

#endif // FFTFrame_h