Man page - biquad(9)

Packages contains this manual

Manual

BIQUAD

NAME
SYNOPSIS
DESCRIPTION
FUNCTIONS
PINS
PARAMETERS
AUTHOR
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

AUTHOR

Peter G. Vavaroutsos

LICENSE

GPL