filter.c File Reference

#include "iLBC_define.h"

Include dependency graph for filter.c:

Go to the source code of this file.

Functions
void	AllPoleFilter (float *InOut, float *Coef, int lengthInOut, int orderCoef)
void	AllZeroFilter (float *In, float *Coef, int lengthInOut, int orderCoef, float *Out)
void	DownSample (float *In, float *Coef, int lengthIn, float *state, float *Out)
void	ZeroPoleFilter (float *In, float *ZeroCoef, float *PoleCoef, int lengthInOut, int orderCoef, float *Out)

Function Documentation

AllPoleFilter()

void AllPoleFilter	(	float *	InOut,
		float *	Coef,
		int	lengthInOut,
		int	orderCoef
	)

Definition at line 19 of file filter.c.

Referenced by AbsQuantW(), iCBSearch(), and ZeroPoleFilter().

    {
       int n,k;

       for(n=0;n<lengthInOut;n++){
           for(k=1;k<=orderCoef;k++){
               *InOut -= Coef[k]*InOut[-k];





           }
           InOut++;
       }
   }

AllZeroFilter()

void AllZeroFilter	(	float *	In,
		float *	Coef,
		int	lengthInOut,
		int	orderCoef,
		float *	Out
	)

Definition at line 52 of file filter.c.

Referenced by ZeroPoleFilter().

    {
       int n,k;

       for(n=0;n<lengthInOut;n++){
           *Out = Coef[0]*In[0];
           for(k=1;k<=orderCoef;k++){
               *Out += Coef[k]*In[-k];
           }
           Out++;
           In++;
       }
   }

DownSample()

void DownSample	(	float *	In,
		float *	Coef,
		int	lengthIn,
		float *	state,
		float *	Out
	)

Definition at line 110 of file filter.c.

References DELAY_DS, FACTOR_DS, FILTERORDER_DS, and stop.

Referenced by enhancerInterface().

    {
       float   o;
       float *Out_ptr = Out;
       float *Coef_ptr, *In_ptr;
       float *state_ptr;
       int i, j, stop;

       /* LP filter and decimate at the same time */

       for (i = DELAY_DS; i < lengthIn; i+=FACTOR_DS)
       {
           Coef_ptr = &Coef[0];
           In_ptr = &In[i];
           state_ptr = &state[FILTERORDER_DS-2];

           o = (float)0.0;

           stop = (i < FILTERORDER_DS) ? i + 1 : FILTERORDER_DS;

           for (j = 0; j < stop; j++)
           {
               o += *Coef_ptr++ * (*In_ptr--);
           }
           for (j = i + 1; j < FILTERORDER_DS; j++)
           {
               o += *Coef_ptr++ * (*state_ptr--);
           }






           *Out_ptr++ = o;
       }

       /* Get the last part (use zeros as input for the future) */

       for (i=(lengthIn+FACTOR_DS); i<(lengthIn+DELAY_DS);
               i+=FACTOR_DS) {

           o=(float)0.0;

           if (i<lengthIn) {
               Coef_ptr = &Coef[0];
               In_ptr = &In[i];
               for (j=0; j<FILTERORDER_DS; j++) {
                       o += *Coef_ptr++ * (*Out_ptr--);
               }
           } else {
               Coef_ptr = &Coef[i-lengthIn];
               In_ptr = &In[lengthIn-1];
               for (j=0; j<FILTERORDER_DS-(i-lengthIn); j++) {
                       o += *Coef_ptr++ * (*In_ptr--);
               }
           }
           *Out_ptr++ = o;
       }
   }

ZeroPoleFilter()

void ZeroPoleFilter	(	float *	In,
		float *	ZeroCoef,
		float *	PoleCoef,
		int	lengthInOut,
		int	orderCoef,
		float *	Out
	)

Definition at line 80 of file filter.c.

References AllPoleFilter(), and AllZeroFilter().

Referenced by StateConstructW(), and StateSearchW().

    {
       AllZeroFilter(In,ZeroCoef,lengthInOut,orderCoef,Out);
       AllPoleFilter(Out,PoleCoef,lengthInOut,orderCoef);
   }