/*

     File: FFTBufferManager.h

 Abstract: This class manages buffering and computation for FFT analysis on input audio data. The methods provided are used to grab the audio, buffer it, and perform the FFT when sufficient data is available

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#include <AudioToolbox/AudioToolbox.h>

#include <libkern/OSAtomic.h>

#include <Accelerate/Accelerate.h>

class FFTBufferManager

{

public:

    FFTBufferManager(UInt32 inNumberFrames);

    ~FFTBufferManager();

    volatile int32_t    HasNewAudioData()   { return mHasAudioData; }

    volatile int32_t    NeedsNewAudioData() { return mNeedsAudioData; }

    UInt32              GetNumberFrames() { return mNumberFrames; }

    void                GrabAudioData(AudioBufferList *inBL);

    Boolean             ComputeFFT(int32_t *outFFTData);

    void                ClearBuffer(void* buffer, UInt32 numBytes);

private:

    volatile int32_t    mNeedsAudioData;

    volatile int32_t    mHasAudioData;

    FFTSetup            mSpectrumAnalysis;

    DSPSplitComplex     mDspSplitComplex;

    Float32             mFFTNormFactor;

    Float32             mAdjust0DB;

    Float32             m24BitFracScale;

    Float32*            mAudioBuffer;

    UInt32              mNumberFrames;

    UInt32              mFFTLength;

    UInt32              mLog2N;

    UInt32              mAudioBufferSize;

    int32_t             mAudioBufferCurrentIndex;

};