fir.c

用c或者c++语言

#include <stdio.h>
#define length 256
int input[length],output[256];
void filter(int xin[],int xout[],int n, int h[]);
static void dataIO(void);
static int h[81]={ 20,	15,	6,	-7	,-20,	-33,	-40,	-36,	-20,	8,	44,	79,	100,	98,	64,	0,	-83,	-166,	-221,	-226,	-166	,-40,	131,	306,	437,	474,	382,	156,	-175,	-544,	-858,	-1013,	-916,	-511,	207,	1183,	2307,	3426,	4379,	5018,	5244,	5018,	4379,	3426,	2307,	1183,	207,	-511,	-916	,-1013,	-858,	-544	,-175,	156,	382,	474,	437,	306,	131,	-40,	-166,	-226,	-221,	-166,	-83,	0,	64,	98,	100,	79,	44,	8,	-20,	-36,	-40,	-33,	-20	,-7,	6,	15,	20};
/*Q15*/
static int x1[256+81];
/*低通滤波定点子程序*/
void filter(int indata[],int outdata[],int n,int h[])
{
	int i,j;
	long sum;
	for(i=0;i<length;i++)x1[n+i-1]=indata[i];
	for(i=0;i<length;i++)
	{
		sum=0;
		for(j=0;j<n;j++) sum+=(long)h[j]*x1[i-j+n-1];
		outdata[i]=sum>>15;
	}
	for(i=0;i<length;i++)x1[n-i-2]=indata[length-i-1];
}
void main()
{ 
   // int indata[256],outdata[256];
   while(1)
   {
	dataIO();
	dataIO();
	filter(input,output,81,h);
	}	
}
static void dataIO()
{
	/*do data I/O*/
	return;
}