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Using the STM32F10x DSP library FIR

Question asked by r.denis on Oct 29, 2013
Latest reply on Nov 14, 2013 by r.denis
I'm unsure on how to use the FIR interface. From the provided example:

int a[N];/*filter output vector*/
short x[M+N-1] = {x0,x1...,xM+N-1};/*filter input vector*/
short h[M]={h0,h1...,hM-1};/*filter coefficients vector*/
fir_coefs.nh = M; /*Number of Coefficients for FIR*/
fir_coefs.h = h; /*Pointer on FIR coefficient vector*/
fir_16by16_stm32(a,x,&fir_coefs,N);/*performs the FIR filtering*/

Suppose I only have 4 samples (the minimum allowed),  I put them into the first 4 elements of x, and call the fir func.
But if i have continuous stream, can i just load again the next 4 same way?
Trying now but I see wrong stuff seems to come out.

(I find the ARM math library fir interface is more clearer in this respect, it keeps the state and input separate)