thank you for your answer @klory
here is my signal with length of 71006
array([ -152.,  -330.,  -306., ..., -2522., -2724., -2886.], dtype=float32)

and filter length is 30
array([ -320.,  -322.,  -340.,  -410.,  -678., -1100.,  -712.,  1580.,
        5190.,  8574., 11104., 12664., 12998., 12104., 10110.,  7030.,
        3232.,  -574., -3596., -4724., -3832., -2558., -2184., -2416.,
       -2560., -2474., -2374., -2394., -2434., -2394.], dtype=float32)

So padding param pads signal on both sides - it changes the data to compensate for filtering, am I getting this right?