[MPlayer-users] Re: Mpeg2 encoding results

[D Richard Felker III]

On Sun, Sep 07, 2003 at 06:42:18PM +0200, Nico wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> 
> Hi Michael,
> 
> 
> > around outlines.
> > can u upload (to ftp://mplayerhq.hu/MPlayer/incoming and tell us that u
> did)
> > short samples (orginal source, lavc encoded, xvid encoded & command line
> > options used for both encodings) which show these problems (gray blocks &
> > mosquitos)
> >
> 
> I added scplx_mask=0.2 to the encoding parameters and it made miracles! Why
> didn't you say it sooner? :)
> Now blocks seem to have almost completely vanished :)
> 
> I wonder if 0.2 is a bit too high, what value do you suggest?
> 
> Is it possible to instruct lavc to encapsulate the cropped image into a
> larger frame, so as to
> encode only the useful part of the video and to add it black borders to keep
> a resolution
> compatible with dvds?

Not directly. But you can use -vf expand with the right options. Try
to make it so that the transition to black border lines up *exactly*
on a multiple-of-16-pixels boundary (or at least multiple of 8) for
maximum quality. You should do this even if it requires scaling the
movie slightly first (i.e. slight aspect distortion), since it should
make a big difference in the quality you get at a fixed bitrate. Of
course if you're making dvd rather than svcd, you can just use a huge
bitrate, so it doesn't matter so much.

Rich