Calculate layers per frame

[PaulBirdUnity]

The layers per frame is a bit off, need to round up. Probably not a big issue and maybe this is the desired behavioiur.

e.g.

197/4 = 49 197 = 49 + 49 + 49 + 49 + 1

so it spreads it over 5 frames instead of 4 and does the output processing on the 5th frame.

197/4+1 = 50 197 = 50 + 50+ 50 + 47