[HELP] Vapoursynth, Frame, Stabilize not working

[zspeciman]

Regarding Stab under Stabilize tab.  The Shift Max X/Y.  If I set it to 4/4.  Does that mean the range it can go 2 up, 2 down, 2 left, 2 right, so a shift a max shift of 4.  Or its 4 up, 4 down, 4 left, 4 right, a max shift of 8?