FIR16 issue

#define	FFT_SIZE	2048
#define	FIR_ORDER	16


typedef struct { 
    long *coeff_ptr;        	/* Pointer to Filter coefficient */
    long *dbuffer_ptr;		/* Delay buffer ptr              */
    int	cbindex;		/* Circular Buffer Index         */
    int order;              	/* Order of the Filter           */
    int input;              	/* Latest Input sample           */ 
    int output;             	/* Filter Output                 */
    void (*init)(void *);   	/* Ptr to Init funtion           */
    void (*calc)(void *);   	/* Ptr to calc fn                */  
    }FIR16; 

FIR16	fir;


int	Buff_acq[4*FFT_SIZE];
int	Spectro[(FFT_SIZE/2)+1];
int     coeff_fidl[17]={ 0.0090*32767,  0.0131*32767,  0.0245*32767,  0.0416*32767,
			 0.0618*32767,  0.0822*32767,  0.0994*32767,  0.1109*32767, 
			 0.1150*32767,  0.1109*32767,  0.0994*32767,  0.0822*32767,  
			 0.0618*32767,  0.0416*32767,  0.0245*32767,  0.0131*32767,  
			 0.0090*32767 };
int     coeff_lb[17]={	0.05850*32767, 0.05850*32767, 0.05850*32767, 0.05850*32767,
			0.05850*32767, 0.05850*32767, 0.05850*32767, 0.05850*32767,
			0.05850*32767, 0.05850*32767, 0.05850*32767, 0.05850*32767,
			0.05850*32767, 0.05850*32767, 0.05850*32767, 0.05850*32767,
			0.05850*32767};


void fir_od16(int *src, int *coeff, int size)
{
	int i;
	long dbuffer[FIR_ORDER+1];

	fir.init=(void (*)(void *))FIR32_init;
	fir.calc=(void (*)(void *))FIR32_calc;
	fir.order=FIR_ORDER;
	fir.dbuffer_ptr=dbuffer;
	fir.coeff_ptr=(long *)coeff;
	fir.init(&fir);

	for (i=0;i<size;i++)
	{
		fir.input=src[i];
		fir.calc(&fir);
		src[i]=fir.output;
	}
}


fir_od16(Buff_acq, coeff_fidl, 4*FFT_SIZE);
fir_od16(Spectro, coeff_lb, ((FFT_SIZE/2)+1));