[mythtv-users] h264 "Prebuffering" pauses (Non XvMC, Non NFS)

[Kingsley Turner]

Hi,

I'm getting "pre-buffering" pauses playing live-tv.  I know this because 
it's in the mythfrontend logfile.
What does this actually mean?  What's it waiting on?  Reading from the 
tv-card?

BBC HD works ok, but Swiss HD has 1/2 second pauses every few seconds 
when there's high motion displayed (I assume the greatest bitrate),

The video signal is a 1280x720 50Hz h264 stream, running at around 
10kbit (or is this mbit?) according to VLC.

I can playback the recorded HD stream OK though, it's only live TV that 
stutters.

I disabled all non-used devices in the BIOS.
I turned off OpenGL synch
I set both RTC and HPET to 1024 in /etc/sysctl.conf

This is a dual-core (10 week old) core2-duo (E7200 at 2.53GHz) with 2G ram, 
SATA2 disk.  CPU use during playback is around 80-105%  So it's using 
about 1/2 it's processing power.

The video-playback configuration is set to use "linear-blend' 
deinterlacer, with a fallback of "none".

It drawing to an onboard nvidia 7100, but i just tried a separate 
pci-x-16 8600GT with absolutely no change in symptoms.

Does commercial flagging run during live TV?  Or is this only 
post-processing for recorded shows?

Would throwing more hardware at this help?  
1066MHz ram instead of 800?
Quad core CPU ?

Although it doesn't seem to be CPU bound ... but before the tuning CPU 
was getting up to 180% (i.e.: almost maxing out both cores)


any hints ?

cheers,
-kt