jens
0179c510fe
git-svn-id: http://moon:8086/svn/software/trunk/libsrc/fir@1 b431acfa-c32f-4a4a-93f1-934dc6c82436
77 lines
1.5 KiB
C
Executable File
77 lines
1.5 KiB
C
Executable File
/*************************************************************************/
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/* fir.c
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/*************************************************************************/
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#include <stdio.h>
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#include <malloc.h>
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#include "math.h"
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#include "fir.h"
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#include "firdecim.h"
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/*************************************************************************/
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/* Global Variables
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/*************************************************************************/
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int FDfilter(struct _sFIRDECIM *pObj, float *pX, float *pY, int len)
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{
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int len2, i, firLen, kL;
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float *pSxt, *pBt, sum;
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kL = pObj->kL;
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firLen = pObj->firLen;
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pBt = &pObj->pB[0];
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pSxt = &pObj->pX[0];
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len2 = 0;
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while (len >= kL)
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{
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for (i = firLen-1; i >= kL; i--)
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{
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pObj->pX[i] = pObj->pX[i- kL];
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}
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for (i = kL-1; i >= 0; i--)
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{
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pObj->pX[i] = *(pX++);
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}
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len -= kL;
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sum = 0.0;
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for (i=0; i < firLen; i++)
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sum += pObj->pX[i] * pObj->pB[i];
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*(pY++) = sum;
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len2++;
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}
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return len2;
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}
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void FDinit(struct _sFIRDECIM *pObj, int kL, int nCoefPerPhase)
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{
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int n;
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pObj->kL = kL;
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pObj->firLen = kL*nCoefPerPhase;
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pObj->nCoefPerPhase = nCoefPerPhase;
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if ((pObj->firLen%2) == 0)
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pObj->firLen++;
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pObj->pB = (float*)malloc(pObj->firLen*sizeof(float));
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pObj->pX = (float*)malloc(pObj->firLen*sizeof(float));
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for(n=0; n < pObj->firLen; n++)
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{
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pObj->pX[n] = 0;
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}
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Sinc(pObj->pB, kL, 1.f/kL, 1.f/kL, pObj->firLen);
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}
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void FDfree(struct _sFIRDECIM *pObj)
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{
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free(pObj->pB);
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free(pObj->pX);
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} |