FFT.h

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#ifndef GRT_FFT_HEADER
#define GRT_FFT_HEADER

#include "../../CoreModules/FeatureExtraction.h"
#include "FastFourierTransform.h"

GRT_BEGIN_NAMESPACE

class GRT_API FFT : public FeatureExtraction
{
public:
    enum FFTWindowFunctionOptions{RECTANGULAR_WINDOW=0,BARTLETT_WINDOW,HAMMING_WINDOW,HANNING_WINDOW};
    
    FFT(const UINT fftWindowSize=512,const UINT hopSize=1,const UINT numDimensions=1,const UINT fftWindowFunction=RECTANGULAR_WINDOW,const bool computeMagnitude=true,const bool computePhase=true);
    
    FFT(const FFT &rhs);
    
    virtual ~FFT(void);
    
    FFT& operator=(const FFT &rhs);
    
    virtual bool deepCopyFrom(const FeatureExtraction *featureExtraction);
    
    virtual bool computeFeatures(const VectorFloat &inputVector);
    
    virtual bool computeFeatures(const MatrixFloat &inputMatrix);
    
    virtual bool clear();
    
    virtual bool reset();
    
    virtual bool save( std::fstream &file ) const;
    
    virtual bool load( std::fstream &file );
    
    bool init(const UINT fftWindowSize,const UINT hopSize=1,const UINT numDimensions=1,const UINT windowFunction=RECTANGULAR_WINDOW,const bool computeMagnitude=true,const bool computePhase=true,const DataType inputType = DATA_TYPE_VECTOR,const DataType outputType = DATA_TYPE_VECTOR);
    
    bool update(const Float x);
    
    bool update(const VectorFloat &x);
    
    bool update(const MatrixFloat &x);
    
    UINT getHopSize() const;
    
    UINT getDataBufferSize() const;
    
    UINT getFFTWindowSize() const;
    
    UINT getFFTWindowFunction() const;
    
    UINT getHopCounter() const;
    
    bool getComputeMagnitude() const { if(initialized){ return computeMagnitude; } return false; }
    
    bool getComputePhase() const { if(initialized){ return computePhase; } return false; }
    
    Vector< FastFourierTransform > getFFTResults() const{ return fft; }
    
    Vector< FastFourierTransform >& getFFTResultsPtr() { return fft; }

    const Vector< FastFourierTransform >& getFFTResultsPtr() const { return fft; }
    
    VectorFloat getFrequencyBins(const unsigned int sampleRate) const;
    
    bool setHopSize(const UINT hopSize);
    
    bool setFFTWindowSize(const UINT fftWindowSize);
    
    bool setFFTWindowFunction(const UINT fftWindowFunction);
    
    bool setComputeMagnitude(const bool computeMagnitude);
    
    bool setComputePhase(const bool computePhase);
    
    //Tell the compiler we are using the following functions from the MLBase class to stop hidden virtual function warnings
    using MLBase::save;
    using MLBase::load;

    static std::string getId();
    
protected:
    bool isPowerOfTwo(UINT x);                                   
    bool validateFFTWindowFunction(UINT fftWindowFunction);
    
    UINT hopSize;                                               
    UINT dataBufferSize;                                        
    UINT fftWindowSize;                                         
    UINT fftWindowFunction;                                     
    UINT hopCounter;                                            
    bool computeMagnitude;                                      
    bool computePhase;                                          
    VectorFloat tempBuffer;                                     
    CircularBuffer< VectorFloat > dataBuffer;                  
    Vector< FastFourierTransform > fft;                         
    std::map< unsigned int, unsigned int > windowSizeMap;       
    
private:
    static RegisterFeatureExtractionModule< FFT > registerModule;
    static std::string id;
    
};

GRT_END_NAMESPACE

#endif //GRT_FFT_HEADER