Biquad< Tv, Tp, Ts > Class Template Reference

2-pole/2-zero IIR filter More...

#include <Filter.h>

Inherits Ts.

List of all members.

Public Member Functions
	Biquad (Tp frq=Tp(1000), Tp res=Tp(1), FilterType type=LOW_PASS)
void	coef (Tp a0, Tp a1, Tp a2, Tp b0, Tp b1, Tp b2)
	Set input (a) and output (b) coefficients directly.
void	freq (Tp v)
	Set center frequency.
void	res (Tp v)
	Set resonance.
void	set (Tp frq, Tp res)
	Set filter center frequency and resonance.
void	set (Tp frq, Tp res, FilterType type)
	Set all filter params.
void	type (FilterType type)
	Set type of filter.
void	zero ()
	Zero internal delays.
Tv	operator() (Tv i0)
	Filter next sample.
Tv	nextBP (Tv i0)
	Optimized for band-pass types.
Tp	freq () const
	Get center frequency.
Tp	res () const
	Get resonance.
FilterType	type () const
	Get filter type.

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Detailed Description

template<class Tv = gam::real, class Tp = gam::real, class Ts = Synced>
class gam::Biquad< Tv, Tp, Ts >

2-pole/2-zero IIR filter

The biquadratic filter contains 2 zeroes and 2 poles in its transfer function. The zeroes provide a better response near the DC and Nyquist frequencies than an all-pole filter would. Second-order IIRs have a 12 dB/octave cutoff slope and are normally cascaded (run in series) to obtain a sharper response. This particular implementation utilizes the Butterworth design.

These filters are adapted from: http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt

Template Parameters:

Tv	value (sample) type
Tp	parameter type
Ts	sync type

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Constructor & Destructor Documentation

Biquad	(	Tp	frq = Tp(1000),
		Tp	res = Tp(1),
		FilterType	type = LOW_PASS
	)

Parameters:

[in]	frq	Center frequency
[in]	res	Resonance amount in [1, inf)
[in]	type	Type of filter

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

• /Users/ljp/code/gamma/trunk/Gamma/Filter.h