To check out this repository please hg clone the following URL, or open the URL using EasyMercurial or your preferred Mercurial client.

The primary repository for this project is hosted at https://github.com/sonic-visualiser/sv-dependency-builds .
This repository is a read-only copy which is updated automatically every hour.

Statistics Download as Zip
| Branch: | Tag: | Revision:

root / src / portaudio_20161030_catalina_patch / qa / loopback / src / biquad_filter.h @ 162:d43aab368df9

History | View | Annotate | Download (866 Bytes)

1 
#ifndef _BIQUADFILTER_H
2 
#define _BIQUADFILTER_H
3 

    		
  

  

    
      4
    
    
      

    		
  

  

    
      5
    
    
      
/**


    		
  

  

    
      6
    
    
      
 *        Unit_BiquadFilter implements a second order IIR filter. 


    		
  

  

    
      7
    
    
      
 *


    		
  

  

    
      8
    
    
      
 * @author (C) 2002 Phil Burk, SoftSynth.com, All Rights Reserved


    		
  

  

    
      9
    
    
      
 */


    		
  

  

    
      10
    
    
      

    		
  

  

    
      11
    
    
      
#define BIQUAD_MIN_RATIO     (0.000001)


    		
  

  

    
      12
    
    
      
#define BIQUAD_MIN_Q         (0.00001)


    		
  

  

    
      13
    
    
      

    		
  

  

    
      14
    
    
      
typedef struct BiquadFilter_s


    		
  

  

    
      15
    
    
      
{


    		
  

  

    
      16
    
    
      
    double      xn1;    // storage for delayed signals


    		
  

  

    
      17
    
    
      
        double      xn2;


    		
  

  

    
      18
    
    
      
        double      yn1;


    		
  

  

    
      19
    
    
      
        double      yn2;


    		
  

  

    
      20
    
    
      

    		
  

  

    
      21
    
    
      
        double      a0;    // coefficients


    		
  

  

    
      22
    
    
      
        double      a1;


    		
  

  

    
      23
    
    
      
        double      a2;


    		
  

  

    
      24
    
    
      

    		
  

  

    
      25
    
    
      
        double      b1;


    		
  

  

    
      26
    
    
      
        double      b2;


    		
  

  

    
      27
    
    
      

    		
  

  

    
      28
    
    
      
        double      cos_omega;


    		
  

  

    
      29
    
    
      
        double      sin_omega;


    		
  

  

    
      30
    
    
      
        double      alpha;


    		
  

  

    
      31
    
    
      
} BiquadFilter;


    		
  

  

    
      32
    
    
      

    		
  

  

    
      33
    
    
      
void BiquadFilter_SetupHighPass( BiquadFilter *filter, double ratio, double Q );


    		
  

  

    
      34
    
    
      
void BiquadFilter_SetupNotch( BiquadFilter *filter, double ratio, double Q );


    		
  

  

    
      35
    
    
      

    		
  

  

    
      36
    
    
      
void BiquadFilter_Filter( BiquadFilter *filter, float *inputs, float *outputs, int numSamples );


    		
  

  

    
      37
    
    
      

    		
  

  

    
      38
    
    
      
#endif