[mythtv-users] Upgrade old or cut my losses and buy new?
adeffs.mythtv at gmail.com
Wed Mar 7 15:06:06 UTC 2007
On 3/6/07, David Murphy <dm1000 at gmail.com> wrote:
> 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
> 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.
I was just going to say, if your CPU is known to be fast enough (ie
others with the same CPU have no issue), check that your output
frequency is correct.
I also *highly* recommend using the 9xxx series drivers for HDTV,
enabling Vsync with the UseTextures=True xorg option. I noticed on my
already working system that doing this dropped my CPU use down while
clearing up any picture issues I was having before (slight tearing
near the top of the screen). The 9xxx series also has the nice
Before you ask, read the FAQ!
then search the Wiki, and this list,
Mailinglist etiquette -
More information about the mythtv-users