[MPlayer-dev-eng] check recommended MPEG2 encoding options

[RC]

On Tue, 6 Mar 2007 00:43:25 +0100
Reimar Döffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de> wrote:

> -lavcopts
> vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=8000:\
> keyint=15:trell:mbd=2:precmp=2:subcmp=2:cmp=2:dia=-10:predia=-10:cbp:
> mv0:\ vqmin=1:lmin=1:dc=10:vstrict=0
> 
> Can someone double-check this a bit?

It's completely wrong, and I have no idea why it was suggested.

The most glaring mistake is using *cmp=2, which causes extreme
blockiness.  Practically no stand-alone DVD/SVCD/VCD players do
postprocessing, so it's just going to look horrible, no matter what.
The default (cmp=0) will look far better.  Either that or *cmp=3 should
be recomended.

cbp and mv0 also appear to make blockiness worse in my tests (but not
by much).  No idea about dc.

vrc_minrate should probably be used.

> man page also suggests (by my reading) that negative values for dia
> are fast but not exactly good.

Hmm...  Positive dia values only go up to 6, while negative values can
go to 99.  I wonder which would look be better in such case.