avir::CLancIR::CResizeFilters Class Reference

#include <lancir.h>

Classes
class	CSinGen

Public Member Functions
float *	getFilter (const double x)
bool	update (const double la, const double k)

Public Attributes
int	KernelLen

Protected Member Functions
template<class T >
void	makeFilter (const double FracDelay, T *op) const
template<class T >
void	normalizeFilter (T *const p) const

Protected Attributes
float *	FilterBuf
int	FilterBufLen
float **	Filters
int	FiltersLen
int	fl2
int	FracCount
int	FracFill
double	Freq
double	FreqA
double	Len2
double	NormFreq
double	Prevk
double	Prevla

Friends
class	CResizeScanline

Detailed Description

Class implements fractional delay filter bank calculation.

Member Function Documentation

float* avir::CLancIR::CResizeFilters::getFilter

(

const double

x

)

Function returns filter at the specified fractional offset. This function can only be called before the prior update() function call.

Parameters

x	Fractional offset, [0; 1).

template<class T >

void avir::CLancIR::CResizeFilters::makeFilter ( const double  FracDelay, T *  op  ) const

protected

Function creates filter for the specified fractional delay. The update() function should be called prior to calling this function. The created filter is not normalized, so it should be normalized afterwards.

Parameters

	FracDelay	Fractional delay, 0 to 1, inclusive.
[out]	Output	filter buffer.

Template Parameters

T	Output buffer type.

template<class T >

void avir::CLancIR::CResizeFilters::normalizeFilter ( T *const  p ) const

protected

Function normalizes the specified filter so that it has unity gain at DC.

Parameters

p	Filter buffer pointer.

Template Parameters

T	Filter buffer type.

bool avir::CLancIR::CResizeFilters::update	(	const double	la,
		const double	k
	)

Function updates the resizing filter bank.

Parameters

la	Lanczos "a" parameter value.
k	Resizing step.

Returns

"True" if update occured and resizing positions should be updated unconditionally.

Member Data Documentation

float* avir::CLancIR::CResizeFilters::FilterBuf

protected

Buffer that holds all filters.

int avir::CLancIR::CResizeFilters::FilterBufLen

protected

Allocated length of FilterBuf in elements.

float** avir::CLancIR::CResizeFilters::Filters

protected

Fractional delay filters for all positions. Filter pointers equal NULL if filter was not yet created.

int avir::CLancIR::CResizeFilters::FiltersLen

protected

Allocated length of Filters in elements.

int avir::CLancIR::CResizeFilters::fl2

protected

Half resampling length, integer.

int avir::CLancIR::CResizeFilters::FracCount

protected

The number of fractional positions for which filters are created.

int avir::CLancIR::CResizeFilters::FracFill

protected

The number of fractional positions filled in the filter buffer.

double avir::CLancIR::CResizeFilters::Freq

protected

Circular frequency of the filter.

double avir::CLancIR::CResizeFilters::FreqA

protected

Circular frequency of the window function.

int avir::CLancIR::CResizeFilters::KernelLen

Resampling filter kernel length, taps. Available after the update() function call.

double avir::CLancIR::CResizeFilters::Len2

protected

Half resampling filter length, unrounded.

double avir::CLancIR::CResizeFilters::NormFreq

protected

Normalized frequency of the filter.

double avir::CLancIR::CResizeFilters::Prevk

protected

Previous "k".

double avir::CLancIR::CResizeFilters::Prevla

protected

Previous "la".