mcdeint=[mode[:parity[:qp]]]
Motion compensating deinterlacer. It needs one field per frame
as input and must thus be used together with tfields=1 or
yadif=1/3 or equivalent.
<mode>
0: fast
1: medium
2: slow, iterative motion estimation
3: extra slow, like 2 plus multiple reference frames
<parity>
0 or 1 selects which field to use (note: no autodetec-
tion yet!).
<qp>
Higher values should result in a smoother motion vector
field but less optimal individual vectors.