[MEncoder-users] Portions of artifacting with libavcodec

[Martin Collins]

On Wed, 23 Nov 2005 23:03:36 -0500
EC <zybhjk at verizon.net> wrote:

> But the output of two recent movies I have done (The Life Aquatic
> and Sin City), have had sections where the mpeg4
> blocking/artifacting is horrible.  Everything except these short
> portions looks perfectly fine.
...
> -lavcopts vcodec=mpeg4:vbitrate=2000:mbd=2:trell:v4mv 
> :cmp=3:subcmp=3:precmp=3:dia=2:vpass=1:autoaspect
> -vf pp=de -o ~/Sin_City.avi
...
> Any hints on how to prevent/get rid of these?

I would suggest trying it without any *cmp options, I've seen weird
effects on motion with them.

Add vratetol=32000 so it can really bump up the bitrate on the tricky
bits.

Sin City is very dark and may well benefit from some denoising. You
could try tinkering with dark_mask as well.

Martin