oooh! must try this at once! thanks for your work
i'll edit this post with feedback rather than take up forum real estate...
[edit]
no surprise here, but sharp luma changes tend to throw this off a tad (a hand with a cigarette lighter flashing is what i'm looking at atm). mvflow looks really good though. very promising already.
[edit 2]
scharfi beat me to it, but there's also a rounding error on the luma plane (i ignored the chroma error by just putting "greyscale" after everything).
@ scharfi: are we running the exact same script here?
[edit 3]
take this for now:
yv12lut(yexpr="x 1 +",uexpr="x 1 +",vexpr="x 1 +",y=3,u=3,v=3)