reinterpolate420 - eliminate chroma jaggyness of PAL-DV

[scharfis_brain]

function reinterpolate420(clip x)
{
	u=x.utoy()
	v=x.vtoy()
	
	u=u.separatefields().separatefields().selectevery(4,1,2).tomsmocomp(1,-1,0).assumefieldbased().weave()
	v=v.separatefields().separatefields().selectevery(4,1,2).tomsmocomp(1,-1,0).assumefieldbased().weave()

	ytouv(u,v,x)
}

this function will only work properly, if your DV-Decoder upsamples the interplaced YUV420 (YV12) Chroma to yuy2 using point-sampling!

the results are IMO very good:



It becomes quite useful, if you intend to deinterlace your PALDV for achieving some kind of Film-Look, for deshaking-pre-processing further filtering etc.