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- /*
- * Atpdec
- * Copyright (c) 2003 by Thierry Leconte (F4DWV)
- *
- * $Id$
- *
- * This library is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
- #include "filter.h"
-
- float fir( float *buff, const float *coeff, const int len)
- {
- int i;
- double r;
-
- r=0.0;
- for(i=0;i<len;i++) {
- r+=buff[i]*coeff[i];
- }
- return r;
- }
-
-
- void iqfir( float *buff, const float *Icoeff, const float *Qcoeff, const int len, float *Iptr,float *Qptr)
- {
- int i;
- float I,Q;
-
- I=Q=0.0;
- for(i=0;i<len;i++) {
- double v;
-
- v=buff[i];
- I+=v*Icoeff[i];
- Q+=v*Qcoeff[i];
- }
- *Iptr=I;
- *Qptr=Q;
- }
-
- float rsfir(float *buff,const float *coeff,const int len , const double offset , const double delta)
- {
- int i;
- double n;
- double out;
-
- out=0.0;
- for(i=0,n=offset;n<len-1;n+=delta,i++) {
- int k;
- double alpha;
-
- k=(int)n;
- alpha=n-k;
- out+=buff[i]*(coeff[k]*(1.0-alpha)+coeff[k+1]*alpha);
- }
-
- return out;
- }
-
- double iir(double x,iirbuff_t *buff,const iircoeff_t *coeff)
- {
- buff->x[4]=buff->x[3];
- buff->x[3]=buff->x[2];
- buff->x[2]=buff->x[1];
- buff->x[1]=buff->x[0];
- buff->x[0]=x/coeff->G;
-
- buff->y[2]=buff->y[1];
- buff->y[1]=buff->y[0];
- buff->y[0] = buff->x[4]
- + coeff->x[2] * buff->x[3]
- + coeff->x[1] * buff->x[2]
- + coeff->x[0] * buff->x[1]
- + buff->x[0]
- + coeff->y[1] * buff->y[2]
- + coeff->y[0] * buff->y[1];
-
- return (buff->y[0]);
- }
-
-
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