SPUC::farrow< Numeric > Class Template Reference

Template Class for Farrow implementation of a ploynomial interpolation using a FIR filter. More...

#include <farrow.h>

Public Member Functions
Numeric	out ()
	Get current output. More...
Numeric	check (long i)
	Clock in new sample & compute current output. More...
	farrow (char order)
	Need to cover different orders! More...
void	reset (void)
	reset More...
	~farrow (void)
void	input (Numeric in)
	Only input new sample. More...
Numeric	update (Numeric in, float_type offset)
Numeric	fir (float_type offset)
	Calculate output for current coefficients. Offset is between 0 and 1. More...
Numeric	rephase (float_type offset)
	Rephase => recalculate coefficients and output for new offset (for upsampling) More...
void	calculate_coeff2 (void)
	Calculate coefficients for linear (not tested) More...
void	calculate_coeff3 (void)
	Calculate coefficients for square. More...
void	calculate_coeff3a (void)
	Calculate coefficients for parabolic. More...
void	calculate_coeff4 (void)
	Calculate coefficients for 4th order. More...

Public Attributes
long	num_taps
std::vector< Numeric >	coeff

Protected Attributes
std::vector< Numeric >	z
Numeric	output

Detailed Description

template<class Numeric>
class SPUC::farrow< Numeric >

Template Class for Farrow implementation of a ploynomial interpolation using a FIR filter.

Farrow implementation of a polynomial interpolation This covers 3 (orders) cases of interpolation

1. Linear (not efficient using this method)
2. Piecewise-Parabolic
3. Cubic Although derived from the Lagrange coefficients the multiplication factor have been simplified to allow simple VLSI implementations. see Interpolation in Digital Modem - Part II, IEEE Trans. on Comms. June 1993.

   Author

   Tony Kirke

   

Constructor & Destructor Documentation

template<class Numeric>

SPUC::farrow< Numeric >::farrow ( char  order )

inline

Need to cover different orders!

template<class Numeric>

SPUC::farrow< Numeric >::~farrow ( void  )

inline

Member Function Documentation

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff2 ( void  )

inline

Calculate coefficients for linear (not tested)

Referenced by SPUC::farrow< float_type >::rephase(), and SPUC::farrow< float_type >::update().

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff3 ( void  )

inline

Calculate coefficients for square.

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff3a ( void  )

inline

Calculate coefficients for parabolic.

Referenced by SPUC::farrow< float_type >::rephase(), and SPUC::farrow< float_type >::update().

template<class Numeric>

void SPUC::farrow< Numeric >::calculate_coeff4 ( void  )

inline

Calculate coefficients for 4th order.

Referenced by SPUC::farrow< float_type >::rephase(), and SPUC::farrow< float_type >::update().

template<class Numeric>

Numeric SPUC::farrow< Numeric >::check ( long  i )

inline

Clock in new sample & compute current output.

template<class Numeric>

Numeric SPUC::farrow< Numeric >::fir ( float_type  offset )

inline

Calculate output for current coefficients. Offset is between 0 and 1.

Referenced by SPUC::farrow< float_type >::rephase(), and SPUC::farrow< float_type >::update().

template<class Numeric>

void SPUC::farrow< Numeric >::input ( Numeric  in )

inline

Only input new sample.

Referenced by SPUC::farrow_upsampler::need_sample().

template<class Numeric>

Numeric SPUC::farrow< Numeric >::out ( )

inline

Get current output.

template<class Numeric>

Numeric SPUC::farrow< Numeric >::rephase ( float_type  offset )

inline

Rephase => recalculate coefficients and output for new offset (for upsampling)

Referenced by SPUC::farrow_upsampler::output().

template<class Numeric>

void SPUC::farrow< Numeric >::reset ( void  )

inline

reset

template<class Numeric>

Numeric SPUC::farrow< Numeric >::update ( Numeric  in, float_type  offset  )

inline

: Update => Clock in new input sample, recalculate coefficients and determine output

Member Data Documentation

template<class Numeric>

std::vector<Numeric> SPUC::farrow< Numeric >::coeff

template<class Numeric>

long SPUC::farrow< Numeric >::num_taps

Referenced by SPUC::farrow< float_type >::farrow(), SPUC::farrow< float_type >::fir(), and SPUC::farrow< float_type >::reset().

template<class Numeric>

Numeric SPUC::farrow< Numeric >::output

protected

template<class Numeric>

std::vector<Numeric> SPUC::farrow< Numeric >::z

protected

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The documentation for this class was generated from the following file:

• farrow.h