[FFmpeg-devel] [PATCH] PAFF: Derivation process for chroma motion vector

[Carl Eugen Hoyos]

Hi!

Michael Niedermayer <michaelni <at> gmx.at> writes:

> > Attached is a patch that removes smearing from PAFF test files I use. It
> > implements Table 8-10 (Derivation of the vertical component of the
> > chroma vector in field coding mode) by only allowing my to be changed if
> > the reference picture is a field. (Cosmetic patch will be applied if
> > accepted.)
> > 
> > For my sample, it has the same effect as Martin Zlomeks patch: I can't
> > see any bottom fields being referenced.
> 
> but if fields of different parity will be referenced then its wrong or
> am i missing something?

If the original code works apart from changing my also for non interlaced
reference frames (if h->ref_cache[list][scan8[n]]&1 really shows the parity of
the referenced field) it will correctly calculate my += +/- 2

I can s/h->ref_cache[list][scan8[n]]/pic->reference
but that is a separate issue IMO.

Carl Eugen