[flossy_cake]

What I meant was, you're shifting the top field up by 0.25 and the bottom field down by 0.25, which in theory should be equivalent to shifting only the bottom field down by 0.5, which is how I was doing it (which is equivalent to shifting it down by 1.0 after the field is upscaled 2x vertically, which helps me visualise in my mind that the field alignment is preserved).

I was just curious to know why you did the 0.25/-0.25 split instead of 0/-0.5 split, whether that had any benefits (I was thinking, maybe that would help with line flicker at the top and bottom most rows of pixels?)