[mythtv-users] Upgrade old or cut my losses and buy new?

David Murphy dm1000 at gmail.com
Tue Mar 6 22:51:39 UTC 2007


matthew.garman at gmail.com wrote:
> How bad is the "occasional jerk or stutter"?  

Well, 99.9% of the playback is smooth but this is one of those things 
where once you start to notice it you can't stop and it will slowly 
begin to drive you crazy.  For me, the libmpeg2 decoder seems to work 
much, much better than XvMC and uses substantially less cpu than XvMC 
which is counter to what I anticipated.

I've been testing on a 1080i recording from my first gen air2pc card. 
It's from the local PBS station and the on-screen display for this 
station always says I am getting 100% signal.

I've narrowed down a couple of scenes that can fairly reliably generate 
a visual stutter.  For example, there is a scene that involves a fairly 
quick horizontal pan across an audience of people.  Usually, once I 
queue up this scene I will see the stutter.  Then if I skip back a few 
seconds and play it again the stutter may or may not be there.  I 
haven't quantified it but let's say the stutter will occur at least 50% 
of the time that the scene is played but it will NEVER occur 100% of the 
  time.

In other cases the stutter occurs on scenes that I wouldn't think should 
be problematic, such as static camera shots of talking heads against 
black backgrounds that should not be very complex at all.

I have an AMD Athlon X2 3600 Brisbane core cpu coming for my seperate 
backend machine.  I'll have the opportunity to temporarily replace the 
Sempron 3400 in my frontend while maintaining the exact same software 
configuration so it will be interesting to see if there is any change 
but I'm not holding my breath.

I've been doing a lot of research of the stuttering issue and there 
seems to be a lot of grumbling and suspicion of the OpenGL vertical sync 
  options but basically I still have no idea what is causing the problem.


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