[mythtv-users] Performance issue

nate s nate.strickland at gmail.com
Sat Oct 16 19:13:18 UTC 2004


I had almost the same problem, and it was helped by using native ALSA
instead of oss emulation.  just change the output device from /dev/dsp
to ALSA:default and see if that helps.

-Nate


On Fri, 15 Oct 2004 16:38:49 -0400, Matt Vollmar <matt at vollmars.com> wrote:
> nate s wrote:
> 
> >nah I don't know about that...
> >
> ><begin anti-celeron rant>
> >
> >you can comapre cache sizes and all that, but the celeron usually will
> >not work as well as it's specs seem to indicate it should.  there's a
> >reason that many people call it the broken processer.  your celeron
> >2.4 just may perform about equally to a athlon-xp 1800, maybe less.
> >
> ><end celeron rant>
> >
> >still, you should be able to do what you want on that hardware...
> >
> >you may as well try turning deinterlacing off completely while you're
> >testing, just to rule it out as a cause
> >
> >have you tried the non-cvs version to see if the problem still occurs?
> >
> >-Nate
> >
> >On Mon, 11 Oct 2004 15:44:04 -0500, Robert Kulagowski <bob at smalltime.com> wrote:
> >
> >
> >>>I would expect a Cel 2.4 to give
> >>>performance 25% better than the PIII/733 or the PIII/800 lines above.
> >>>I would not expect your system to be capable of recording and viewing
> >>>live tv at the same time.  I'm building my first Mythbox from my
> >>>Athlon 800, but I'm using a pvr-250 (or a 350) as my base encoder to
> >>>reach the performance needed.
> >>>
> >>>
> >>>
> >>
> OK, I've tested a bunch of different things and I'm still having the
> same problems (pre-buffering pause and general stuttering in video but
> not audio).  Here is what I've tested to try to narrow this down:
> 
> 1)  Turn off XvMC.  Result:  No difference in CPU utilization or performance
> 2)  Turn on/off OpenGL sync.  Result:  No difference, other than quality
> seems a little worse without it
> 3)  Turn off deinterlace altogether.  Result:  No difference in CPU or
> performance but much uglier
> 4)  Tried to use Alsa 1.0.5a, but it just messed up my system, so I
> re-installed 1.0.6.  Mandrake is funny like that.
> 5)  Tried changing the capture resolution, which did not change
> ANYTHING!!!  Not even load.  Interesting.
> 
> I'm now compiling different versions of the front/backend using
> different options so that I can immediately compare them.  Here is the
> one thing I've noticed:
> 
> Playback seems to take about 30% of the CPU, which seems normal
> according to what I've read.  But backend recording takes 70% or more.
> I've also noticed that when I start up "Watch TV", I get 3 prebuffering
> pauses, then no more.  The rest of the time, the playback is just a
> little too choppy to be watchable.  Ultimately, I'm not really concerned
> with Watching TV, but I want to be able to watch a movie while something
> else is recording.  Who knows when something might be scheduled, and I
> would rather not worry about it.
> 
> If it is Alsa, I may either just deal with it or try more thoroughly to
> fix it, but I have a feeling it is not.  I use "btaudio" to capture.
> Could that be it?
> 
> Matt
> _______________________________________________
> 
> 
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>


More information about the mythtv-users mailing list