ARDOUR::DSP::Biquad Class Reference

#include <dsp_filter.h>

Public Types
enum	Type {   LowPass , HighPass , BandPassSkirt , BandPass0dB ,   Notch , AllPass , Peaking , LowShelf ,   HighShelf , MatchedLowPass , MatchedHighPass , MatchedBandPass0dB ,   MatchedPeaking }

Public Member Functions
	Biquad (double samplerate)
	Biquad (const Biquad &other)
void	run (float *data, const uint32_t n_samples)
void	compute (Type t, double freq, double Q, double gain)
void	configure (double a1, double a2, double b0, double b1, double b2)
void	configure (Biquad const &)
float	dB_at_freq (float freq) const
void	reset ()
void	coefficients (double &a1, double &a2, double &b0, double &b1, double &b2) const

Private Member Functions
void	set_vicanek_poles (const double W0, const double Q, const double A=1.0)
void	calc_vicanek (const double W0, double &A0, double &A1, double &A2, double &phi0, double &phi1, double &phi2)

Private Attributes
double	_rate
float	_z1
float	_z2
double	_a1
double	_a2
double	_b0
double	_b1
double	_b2

Detailed Description

Biquad Filter

Definition at line 221 of file dsp_filter.h.

Member Enumeration Documentation

Type

enum ARDOUR::DSP::Biquad::Type

Enumerator
LowPass
HighPass
BandPassSkirt
BandPass0dB
Notch
AllPass
Peaking
LowShelf
HighShelf
MatchedLowPass
MatchedHighPass
MatchedBandPass0dB
MatchedPeaking

Definition at line 223 of file dsp_filter.h.

Constructor & Destructor Documentation

Biquad() [1/2]

ARDOUR::DSP::Biquad::Biquad

(

double

samplerate

)

Instantiate Biquad Filter

Parameters

samplerate

Samplerate

Biquad() [2/2]

ARDOUR::DSP::Biquad::Biquad

(

const Biquad &

other

)

Member Function Documentation

calc_vicanek()

void ARDOUR::DSP::Biquad::calc_vicanek ( const double  W0, double &  A0, double &  A1, double &  A2, double &  phi0, double &  phi1, double &  phi2  )

private

coefficients()

void ARDOUR::DSP::Biquad::coefficients	(	double &	a1,
		double &	a2,
		double &	b0,
		double &	b1,
		double &	b2
	)		const

compute()

void ARDOUR::DSP::Biquad::compute	(	Type	t,
		double	freq,
		double	Q,
		double	gain
	)

setup filter, compute coefficients

Parameters

t	filter type (LowPass, HighPass, etc)
freq	filter frequency
Q	filter quality
gain	filter gain

configure() [1/2]

void ARDOUR::DSP::Biquad::configure

(

Biquad const &

)

configure() [2/2]

void ARDOUR::DSP::Biquad::configure	(	double	a1,
		double	a2,
		double	b0,
		double	b1,
		double	b2
	)

setup filter, set coefficients directly

dB_at_freq()

float ARDOUR::DSP::Biquad::dB_at_freq

(

float

freq

)

const

filter transfer function (filter response for spectrum visualization)

Parameters

freq

frequency

Returns

gain at given frequency in dB (clamped to -120..+120)

reset()

void ARDOUR::DSP::Biquad::reset ( )

inline

reset filter state

Definition at line 274 of file dsp_filter.h.

run()

void ARDOUR::DSP::Biquad::run	(	float *	data,
		const uint32_t	n_samples
	)

process audio data

Parameters

data	pointer to audio-data
n_samples	number of samples to process

set_vicanek_poles()

void ARDOUR::DSP::Biquad::set_vicanek_poles ( const double  W0, const double  Q, const double  A = 1.0  )

private

Member Data Documentation

_a1

double ARDOUR::DSP::Biquad::_a1

private

Definition at line 283 of file dsp_filter.h.

_a2

double ARDOUR::DSP::Biquad::_a2

private

Definition at line 283 of file dsp_filter.h.

_b0

double ARDOUR::DSP::Biquad::_b0

private

Definition at line 284 of file dsp_filter.h.

_b1

double ARDOUR::DSP::Biquad::_b1

private

Definition at line 284 of file dsp_filter.h.

_b2

double ARDOUR::DSP::Biquad::_b2

private

Definition at line 284 of file dsp_filter.h.

_rate

double ARDOUR::DSP::Biquad::_rate

private

Definition at line 281 of file dsp_filter.h.

_z1

float ARDOUR::DSP::Biquad::_z1

private

Definition at line 282 of file dsp_filter.h.

_z2

float ARDOUR::DSP::Biquad::_z2

private

Definition at line 282 of file dsp_filter.h.

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

• dsp_filter.h