[mythtv-users] Where's the playback bottleneck?

[Jerry Rubinow]

On 1/24/06, Steve Adeff <adeffs at gmail.com> wrote:
> On Tuesday 24 January 2006 20:31, Robert Johnston wrote:
> > On 1/24/06, Jerry Rubinow <jerrymr at gmail.com> wrote:
> > > If I playback an HD resolution file, I get stuttering, pick a codec, any
> > > codec.
> > >
> > > If I play it back with mplayer (-vo xv -vc ffmpeg12), also stuttering.
> > >  If I play it back with mplayer (-vo xvmc -vc ffmpeg12mc), plays back
> > > pretty much ok.
> > >
> > > In all cases, myth and mplayer, CPU is between 20% and 50% (this is on
> > > a combined front/backend, P4 2.8 Pundit, with onboard VGA disabled,
> > > using a PCI FX5200).
> > >
> > > The fact that I can playback the file in mplayer with xvmc, tells me
> > > it's not a disk issue, and the fact that mplayer cannot play it back
> > > smoothly with xv tells me it's probably not a myth issue.
> > >
> > > Is it a bandwidth problem in the video card or the bus?  Some BIOS
> > > setting incorrect?  Does anyone have any suggestions for how to narrow
> > > it down and tell for sure where the problem might be?
> > >
> > > Is anyone using an original (sis-based) Pundit for HD playback
> > > successfully?
> >
> > If you can play back using mplayer (and XvMC), it means you can enable
> > XvMC in Myth and have smooth HDTV playback.
>
> other than that it sounds like a CPU speed issue.
>
> --
> Steve

I don't understand how it could be a CPU speed issue if usage if below 50%.

-Jerry