[mythtv] 'WriteAudio: buffer underrun' during playback

Lincoln Dale ltd at interlink.com.au
Mon Sep 11 13:27:18 UTC 2006

> Could this not be IO load that is causing the stutter? I would have
> thought that the IO caused by mysql during the reschedule could be
> hampering the frontend from reading from the ringbuffer. As IO isn't
> prioritised according to thread priority (yet! is it?), this would explain
> why it still happens despite the frontend thread being realtime.

unlikely that its I/O bound limitations.  as a quick way of proving one way
or the other, simply put your database on a different spindle to that of
your media.

the ringbuffer has been recently written-to.  that means it'll be in the
buffer cache.  unless you're swapping.  which is bad.

> I am getting the same problem, on a 2.4Ghz celeron, without HT, but with
> DVB cards so there's no encoding load. max load is around 19%, yet I still
> get stutters, and I suspect it's IO.

out of interest, are you on usleep-busywait also?



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