[mythtv] timestretch == prebuffering pause

John P Poet jppoet at gmail.com
Thu Dec 29 00:17:54 EST 2005

On 12/28/05, Daniel Kristjansson <danielk at cuymedia.net> wrote:
> On Wed, 2005-12-28 at 20:53 -0700, John P Poet wrote:
> > I have seperate backend/frontend machines.  I record mostly HDTV with
> > a small amount of SD material.
> >
> > Timestretch seems to work fine at any speed with SD material.
> >
> > Playback is fine when watching HD material at 1.0 speed.  At 1.1 or
> > 1.2 speed, playback is fine as long as the OSD is not up.  At 1.3
> > speed, HD material results in a "prebuffering pause" every couple of
> > seconds even when the OSD is not up:
> What is your CPU usage? If it is above 80% that is probably the cause.
> If not, I don't know what could be causing this. But it does look like
> the problem is on the decoding side not the display side since most of
> the frames are 'A'vailable.
> -- Daniel

top reports 53% CPU usage, with spikes up to 59%.  Load average is around 2.15.

So, 'A'vailable means that the data has been sent from the backend,
and the frontend just needs to "decode" it?  So, messing with the
backend/frontend buffering is not going to help...

Since my CPU usage is only 60%, I tried renicing mythfrontend to -3,
and X to -4.  That *may* have help a little bit, but not much.

Oh well, not that big of a deal.  I doubt I will use a timestretch >
1.2 very often, but I figured that I should be able to make it work.

Thanks for the note, Daniel.


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