[MEncoder-users] Portions of artifacting with libavcodec

[Rich Felker]

On Wed, Nov 23, 2005 at 11:03:36PM -0500, EC wrote:
> I have been using mencoder + lavc mpeg4 to encode dvds and for the most
> part it has been working out great.
> 
> 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.
> 
> Here are two examples: http://ec.firetiger.com/blocked1.jpg
> http://ec.firetiger.com/blocked2.jpg
> 
> In the first movie, this happens in a scene with a lot of fast camera
> panning and water, and in the second it is after an abrupt switch to a
> rainstorm.  I guess these are tough scenes to encode, but it seems like
> it shouldn't be _so much_ of a problem.  Here are the -lavcopts strings
> I am using:
> 
> -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

I hope you also did the second pass with vpass=2? If not you should
expect it to look like crap..

Rich