biquad_filter.c File Reference

#include <math.h>
#include <string.h>
#include "biquad_filter.h"

Macros
#define	FILTER_PI   (3.141592653589793238462643)

Functions
void	BiquadFilter_SetupHighPass (BiquadFilter *filter, double ratio, double Q)
void	BiquadFilter_SetupNotch (BiquadFilter *filter, double ratio, double Q)
void	BiquadFilter_Filter (BiquadFilter *filter, float *inputs, float *outputs, int numSamples)

Macro Definition Documentation

#define FILTER_PI   (3.141592653589793238462643)

 Unit_BiquadFilter implements a second order IIR filter. 
 Here is the equation that we use for this filter:

y(n) = a0*x(n) + a1*x(n-1) + a2*x(n-2) - b1*y(n-1) - b2*y(n-2)

Author

(C) 2002 Phil Burk, SoftSynth.com, All Rights Reserved

Function Documentation

void BiquadFilter_Filter	(	BiquadFilter *	filter,
		float *	inputs,
		float *	outputs,
		int	numSamples
	)

References BiquadFilter_s::a0, BiquadFilter_s::a1, BiquadFilter_s::a2, BiquadFilter_s::b1, BiquadFilter_s::b2, BiquadFilter_s::xn1, BiquadFilter_s::xn2, BiquadFilter_s::yn1, and BiquadFilter_s::yn2.

Referenced by PaQa_FilterRecording().

void BiquadFilter_SetupHighPass	(	BiquadFilter *	filter,
		double	ratio,
		double	Q
	)

References BiquadFilter_s::a0, BiquadFilter_s::a1, BiquadFilter_s::a2, BiquadFilter_s::alpha, BiquadFilter_s::b1, BiquadFilter_s::b2, BIQUAD_MIN_Q, BIQUAD_MIN_RATIO, and BiquadFilter_s::cos_omega.

Referenced by PaQa_DetectPop().

void BiquadFilter_SetupNotch	(	BiquadFilter *	filter,
		double	ratio,
		double	Q
	)

References BiquadFilter_s::a0, BiquadFilter_s::a1, BiquadFilter_s::a2, BiquadFilter_s::alpha, BiquadFilter_s::b1, BiquadFilter_s::b2, BIQUAD_MIN_Q, BIQUAD_MIN_RATIO, and BiquadFilter_s::cos_omega.

Referenced by PaQa_DetectPop().