[MPlayer-users] Eagles - Hell Freezes over DVD

[Francois Visagie]

> -----Original Message-----
> From: mplayer-users-bounces at mplayerhq.hu 
> [mailto:mplayer-users-bounces at mplayerhq.hu] On Behalf Of 
> Vladimir Mosgalin
> Sent: 13 July 2006 12:30
> To: MPlayer usage questions, feature requests, bug reports
> Subject: Re: [MPlayer-users] Eagles - Hell Freezes over DVD
> 
> > The command line I used is below (called from a script, hence the 
> > '$1', '$2' etc) Video issues with Hell Freezes Over are 'blocky' 
> > video, particularly scenes with dark backgrounds, people with dark 
> > clothing etc. Also the 'fog'
> > generated on stage appears blocky. (This is one of the 
> reasons I chose 
> > Desperado as my second attempt - there's a few smoking scenes)
> 
> Fog/smoke scenes are really hard to encode. Both lavc and 
> xvid can't deal with them on medium bitrate.
> 
> If you have a lot of these effects, first thing you should 
> try is xvid.
> When given enough bitrate, xvid can deal with them pretty 
> well, at least better than lavc with qscale=2. Usually, this 
> is enough.
> However, on some scenes, xvid won't be able to produce a nice picture.
> In that case, you have to use lavc with qscale=1. It will use 
> insane bitrates, however. On the other case, usually it 
> guesses these kind of scenes pretty well, and won't encode 
> anything else with such small qscale.
> If it still doesn't look good on the bitrate you can afford, 
> you should try zones feature. I don't know if they work in 
> lavc right now, but at least they do in xvid. You can 
> manually give more bitrate to bad-looking scenes.

Excellent advice all round. I also find that under circumstances like these
XviD gives up some resolution, hence the blocking during playback. The same
happens during fast movement of large objects or display areas.

As suggested by Vladimir, you can elect to leave some of the processing for
playback time. In your config file, use
vf=pp=hb/vb
for deblocking. You can adjust its parameters, but I find the defaults work
very well. The same approach of playback deblocking work very well in other
players/decoders too, e.g. turning on deblocking in the Windows XviD decoder
for Windows players. This gives you the option of deciding that you don't
mind producing files that actually contain some blocking.

If you are getting interlacing as Vladimir suspects,
vf-add=pp=ci
works very well for me on files that are actually interlaced. If used as a
default option it sligthly but noticably degrades quality for non-interlaced
files, so rather use it on demand via the command line and/or config
profiles.

Regards,
Francois





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