[MPlayer-users] Encoding issues.

[D Richard Felker III]

On Thu, Jan 22, 2004 at 03:29:45PM -0800, avery lewis wrote:
> Hey guys,
> 
> I'm rather new to the encoding scene, but I've RTFM'd a few times over now, 
> and though I'm not getting everything, I get enough to get by..
> 
> But I've got some issues.  :)
> 
> I'm encoding animation using lavc, and I'll give you one of my example 
> cmdlines here:

First of all, animation is almost certainly _telecined_, not
_interlaced_, so you should not be using deinterlacers but inverse
telecine filters.

> mencoder dvd://1 -alang en -o /encode/output/ohpain_1.avi -ovc lavc 
> -lavcopts vcodec=mpeg4:vhq:vbitrate=1000 -oac mp3lame -lameopts cbr:vol=3 
> -vop pp=(linblenddeint or mediandeint or 0x2000)
> 
> Here's the problem I'm getting...
> 
> If I encode at too high a bitrate (over 800) I get serious artifacts but a 
> very nice picture quality.  Deinterlacing seems to be perfect.  I don't 
> know how to describe the artifacts exactly.. they usually happen when a 
> screen goes from something to nothing (black out before commercials, etc).  
> It's sort of like what's described as freezed frames on 
> (http://www31.brinkster.com/kaiousama/artifacts.htm) except that it only 
> stays up for a second, and then goes away.
> 
> However.. should I encode at a LOWER bitrate than 800, the major artifacts 
> go away and I'm left with what's referred to as ringing (at least on 
> http://www31.brinkster.com/kaiousama/artifacts.htm)
> 
> I'm really at a loss here.. I'm using lavc, but I've also tried xvid (which 
> is way worse), and ffmpeg (equally bad).  Filesize isn't so much as issue, 
> I'm willing to take files up to 200Mg on 22 minutes of encoded animation.  
> I've tried variable bitrate, with no success.  Is the "perfect encode" 
> unattainable?  Am I chasing a dream?

Well you should try proper inverse telecine, and see if the problem
persists. If so, upload a clip of the source dvd that shows the
problem and hopefully someone can identify what's causing it.

Rich