[mythtv-users] Stuttering

[William Powers]

Thomas Worthington wrote:
> I'm recording from DVB-T so the files are normal mpegs. They play
> perfectly in mplayer without realtime threads, but even with realtime
> enabled the same files have a tiny stutter about every three seconds. This
> is no problem most of the time but during tracking shots or text scrolling
> it is very distracting.
I just recently finished a long period of trial and effort to eliminate 
the same kinds of stuttering you describe.  In my case, I only saw the 
stuttering while the transcoder was running, but that still happened 
often enough to be annoying.  I tried a lot of things, cheapest first, 
and a few of them helped but most of them didn't.  In my case, the 
things that did help are, ranked from most help to least help:

1.  Increased physical memory, first from 512M to 1G, then to 2G.
2.  Upgraded from a 2.8G Northwood P4 to a dual-core Pentium D 820.
3.  Changed the hard drive used to hold the video partition from PATA100 
to SATA150.
4.  Enabled write-caching on the hard drive used to store the recordings.
5.  Set 'swappiness' to zero.
6.  Reduced the PCI latency of the VGA card to be in-line with that of 
other devices.

Because I didn't perform them in that order, I can't be certain I would 
have had to do all of them to fix the problem.  For example, increasing 
the physical memory from 512M to 1G is what finally ended the stuttering 
completely.  It's possible I would never had to do some or all of the 
others if I had increased the memory first.