r8b::CDSPFIRFilter Class Reference

Calculation and storage class for FIR filters. More...

#include <CDSPFIRFilter.h>

Inheritance diagram for r8b::CDSPFIRFilter:

Public Member Functions
int	getBlockLenBits () const
const double *	getKernelBlock () const
int	getKernelLen () const
int	getLatency () const
double	getLatencyFrac () const
bool	isZeroPhase () const
void	unref ()

Static Public Member Functions
static double	getLPMaxAtten ()
static double	getLPMaxTransBand ()
static double	getLPMinAtten ()
static double	getLPMinTransBand ()

Friends
class	CDSPFIRFilterCache

Detailed Description

Calculation and storage class for FIR filters.

Class that implements calculation and storing of a FIR filter (currently contains low-pass filter calculation routine designed for sample rate conversion). Objects of this class cannot be created directly, but can be obtained via the CDSPFilterCache::getLPFilter() static function.

Member Function Documentation

getBlockLenBits()

int r8b::CDSPFIRFilter::getBlockLenBits

(

)

const

Returns

Filter's block length, expressed as Nth power of 2. The actual length is twice as large due to zero-padding.

getKernelBlock()

const double * r8b::CDSPFIRFilter::getKernelBlock

(

)

const

Returns

Filter's kernel block, in complex-numbered form obtained via the CDSPRealFFT::forward() function call, zero-padded, gain-adjusted with the CDSPRealFFT::getInvMulConst() * ReqGain constant, immediately suitable for convolution. Kernel block may have "zero-phase" response, depending on the isZeroPhase() function's result.

getKernelLen()

int r8b::CDSPFIRFilter::getKernelLen

(

)

const

Returns

Filter kernel length, in samples. Not to be confused with the block length.

getLatency()

int r8b::CDSPFIRFilter::getLatency

(

)

const

Returns

Filter's latency, in samples (integer part).

getLatencyFrac()

double r8b::CDSPFIRFilter::getLatencyFrac

(

)

const

Returns

Filter's latency, in samples (fractional part). Always zero for linear-phase filters.

getLPMaxAtten()

static double r8b::CDSPFIRFilter::getLPMaxAtten ( )

static

Returns

The maximal allowed low-pass filter's stop-band attenuation, in decibel.

getLPMaxTransBand()

static double r8b::CDSPFIRFilter::getLPMaxTransBand ( )

static

Returns

The maximal allowed low-pass filter's transition band, in percent.

getLPMinAtten()

static double r8b::CDSPFIRFilter::getLPMinAtten ( )

static

Returns

The minimal allowed low-pass filter's stop-band attenuation, in decibel.

getLPMinTransBand()

static double r8b::CDSPFIRFilter::getLPMinTransBand ( )

static

Returns

The minimal allowed low-pass filter's transition band, in percent.

isZeroPhase()

bool r8b::CDSPFIRFilter::isZeroPhase

(

)

const

Returns

"True" if kernel block of *this filter has zero-phase response.

unref()

void r8b::CDSPFIRFilter::unref

(

)

This function should be called when the filter obtained via the filter cache is no longer needed.