[mythtv-users] Optimizing HD playback with VDPAU?

[Mark Kendall]

On 3 June 2010 15:12, Matt Goebel <matt at goebelnet.com> wrote:
> I have a couple shiney new mythfrontends that I'm doing almost all HD with
> (HDPVR and HDHomerun).  One system is a backend/frontend the other is just a
> frontend.  For the most part they both work flawlessly.  However, on the
> frontend only system I've noticed every once and in a while I see a very
> mild video stutter when there is a lot of motion going on, audio is fine
> though. Most people probably wouldn't notice it but I do.

If you want a reasonably good indicator of 'stutter', run your
frontend with -v playback logging and look at the jitterometer output.
These are the lines that show something like:-

'video_output' mean = '42411.11', std. dev. = '50539.86', fps = '23.58'

You'll want to focus on whether the fps and standard deviation are
consistent and reasonable. Stutter may be happening all of the time
but you never notice it during static scenes.

Other than that I would check that deinterlacing is working as
intended and that the refresh rate of the display is appropriate to
your source material (i.e. 60hz ish for ATSC/NTSC or 50Hz for PAL).

Remember also that some jerkiness is absolutely normal when you see
fast panning in a scene - the amount of movement is just too great for
a 50/60Hz display to smooth out (which of course may be what your
120Hz TV is doing for your cable box input if it has decent image
processing).

>  Same system
> every once in awhile while I'm watching live TV I'll get a couple second
> freeze then resume as normal as well.

Check your logs - this is almost certainly the switch from one program
to the next.

regards

Mark