[mythtv-users] Jumpy playback with PVR-250?

Andrew Dodd atd7 at cornell.edu
Fri Jan 16 18:23:20 EST 2004

Quoting Scott Pouliot <spouliot at scpsoftware.net>:

> I'll try the extra audio buffering once I find it  ;-)
> As far as the pauses...they happen as little as 10 seconds into watching
> LIVE TV...with no recording going on in the background.  I haven't changed
> anything on this box in like a week and it's been running great.  All of a
> sudden I played a recording I taped a few days back and it started freaking
> out on me.

Live TV = a recording mode that deletes the file when you're done.

Try playback of a pre-recorded file when no other shows are being recorded.  If
the stutters still exist, that rules out disk thrashing.

Others suggested hdparm -d1, but honestly there's NO WAY you're getting the
hdparm -t numbers you've mentioned unless DMA is working fine.  As far as I can
tell, the hard drive does not seem to be the limiting factor unless you're
thrashing it.  Considering I currently have my video storage on an external
Firewire drive formatted with FAT32 (i.e. VERY non-optimal), the HD shouldn't be
your problem.

If you've already got the nvidia drivers running and XvMC installed (Requires a
MythTV recompile, you know it's working if your OSD turns greyscale.), it sounds
like the video system is not your problem.  (Unless you've accidentally entered
16bpp mode - do xvinfo, make sure everything's depth is listed as 24 or 32.)

CPU usage is low too...

I had brief (sometimes nasty) stutters with similar conditions to yours (if not
worse in some regards), combining XvMC at 24bpp with the "extra audio buffering"
fixed my problems.

The buffering selection is in TV Settings-> Playback somewhere.  (I think...)

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