dsp::biquad_d2 Struct Reference

#include <biquad.h>

Inheritance diagram for dsp::biquad_d2:

Public Member Functions
	biquad_d2 ()
	Constructor (initializes state to all zeros).
double	process (double in)
	direct II form with two state variables
double	process_lp (double in)
bool	empty () const
	Is the filter state completely silent? (i.e. set to 0 by sanitize function).
void	sanitize ()
	Sanitize (set to 0 if potentially denormal) filter state.
void	reset ()
	Reset state variables.
Public Member Functions inherited from dsp::biquad_coeffs
	biquad_coeffs ()
void	set_null ()
void	set_lp_rbj (float fc, float q, float sr, float gain=1.0)
void	set_lp_zoelzer (float fc, float q, float odsr, float gain=1.0)
void	set_hp_rbj (float fc, float q, float esr, float gain=1.0)
void	set_hp_rbj_optimized (float fc, float q, float esr, float gain=1.0)
void	set_bp_rbj (double fc, double q, double esr, double gain=1.0)
void	set_br_rbj (double fc, double q, double esr, double gain=1.0)
void	set_allpass (float freq, float pole_r, float sr)
void	set_bilinear (double aa0, double aa1, double aa2, double ab0, double ab1, double ab2)
	set digital filter parameters based on given analog filter parameters
void	set_bilinear_direct (double aa0, double aa1, double aa2, double ab1, double ab2)
	set digital filter parameters directly
void	set_peakeq_rbj (double freq, double q, double peak, double sr)
void	set_lowshelf_rbj (float freq, float q, float peak, float sr)
void	set_highshelf_rbj (float freq, float q, float peak, float sr)
void	copy_coeffs (const biquad_coeffs &src)
	copy coefficients from another biquad
float	freq_gain (float freq, float sr) const
cfloat	h_z (const cfloat &z) const

Public Attributes
double	w1
	state[n-1]
double	w2
	state[n-2]
Public Attributes inherited from dsp::biquad_coeffs
double	a0
double	a1
double	a2
double	b1
double	b2

Additional Inherited Members
Public Types inherited from dsp::biquad_coeffs
typedef std::complex< double >	cfloat
Static Public Member Functions inherited from dsp::biquad_coeffs
static double	prewarp (float freq, float sr)
	prewarping for bilinear transform, maps given digital frequency to analog counterpart for analog filter design
static double	unwarp (float omega, float sr)
	convert analog angular frequency value to digital
static double	unwarpf (float t, float sr)
	convert analog filter time constant to digital counterpart

Detailed Description

Two-pole two-zero filter, for floating point values. Uses slightly faster Direct II form (combined FIR and IIR halves). However, when used with wildly varying coefficients, it may make more zipper noise than Direct I form, so it's better to use it when filter coefficients are not changed mid-stream.

Constructor & Destructor Documentation

biquad_d2()

dsp::biquad_d2::biquad_d2 ( )

inline

Constructor (initializes state to all zeros).

Member Function Documentation

empty()

bool dsp::biquad_d2::empty ( ) const

inline

Is the filter state completely silent? (i.e. set to 0 by sanitize function).

process()

double dsp::biquad_d2::process ( double in )

inline

direct II form with two state variables

process_lp()

double dsp::biquad_d2::process_lp ( double in )

inline

reset()

void dsp::biquad_d2::reset ( )

inline

Reset state variables.

sanitize()

void dsp::biquad_d2::sanitize ( )

inline

Sanitize (set to 0 if potentially denormal) filter state.

Member Data Documentation

w1

double dsp::biquad_d2::w1

state[n-1]

w2

double dsp::biquad_d2::w2

state[n-2]

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

• /home/runner/work/lmms-fork/lmms-fork/plugins/LadspaEffect/calf/veal/src/calf/biquad.h