BIQUAD

NAME
SYNOPSIS
DESCRIPTION
FUNCTIONS
PINS
PARAMETERS
LICENSE

NAME

biquad − Biquad IIR filter

SYNOPSIS

loadrt biquad [count=N|names=name1[,name2...]]

DESCRIPTION

Biquad IIR filter. Implements the following transfer function: H(z) = (n0 + n1z-1 + n2z-2) / (1+ d1z-1 + d2z-2)

FUNCTIONS

biquad.N

(requires a floating-point thread)

PINS

biquad.N.in

float in Filter input.

biquad.N.out

float out Filter output.

biquad.N.enable

bit in (default: 0) Filter enable. When false, the in pin is passed to the out pin without any filtering. A transition from false to true causes filter coefficients to be calculated according to the current type and the describing pin and parameter settings

biquad.N.valid

bit out (default: 0) When false, indicates an error occurred when calculating filter coefficients (require 2>Q>0.5 and f0>sampleRate/2)

biquad.N.type

u32 in (default: 0) Filter type determines the type of filter coefficients calculated. When 0, coefficients must be loaded directly from the n0,n1,n2,d1 params. When 1, a low pass filter is created specified by the f0,Q pins. When 2, a notch filter is created specified by the f0,Q pins.

biquad.N.f0

float in (default: 250.0) The corner frequency of the filter.

biquad.N.Q

float in (default: 0.7071) The Q of the filter.

biquad.N.s1

float out (default: 0.0) 1st-delayed internal state (for debug only)

biquad.N.s2

float out (default: 0.0) 2nd-delayed internal state (for debug only)

PARAMETERS

biquad.N.d1

float rw (default: 0.0) 1st-delayed denominator coef

biquad.N.d2

float rw (default: 0.0) 2nd-delayed denominator coef

biquad.N.n0

float rw (default: 1.0) non-delayed numerator coef

biquad.N.n1

float rw (default: 0.0) 1st-delayed numerator coef

biquad.N.n2

float rw (default: 0.0) 2nd-delayed numerator coef

LICENSE

GPL