[mythtv-users] Mac OS X choppy playback at high display resolutions, such as 1080p
Todd Ignasiak
todd.ignasiak at gmail.com
Tue Oct 9 23:05:21 UTC 2007
On 10/9/07, Eric Robinson <ryunokokoro at gmail.com> wrote:
> > What sort of display are you connected to? This problem, as far as I
> > can tell, only happens on very high resolution displays. I have seen
> > several reports of it with 1080p displays, and I see it on a 24" iMac
> > with 1920x1200 display.
> >
> > On my Mini, which is connected to a 720p display, I never see this
> > problem. So, I just want to make sure we're seeing the same thing.
>
> I have three brand new 2.0Ghz minis. One of them is connected to a
> brand new Sharp LC52D64U through HDMI at 1080p (1900x1080). That is
> the only monitor that appears to have the issue. I haven't been able
> to confirm 100% with the other minis running on 720p Vizio TVs but the
> playback seems smooth enough when it's not waiting for buffering
> (they're wirelessly connected via a weak 802.11a signal currently).
Good, 1080p. We're most likely seeing the same thing.
> MENU: Utilities/Setup -> Setup -> TV Settings -> Playback -> Mac OSX
> Video Settings 1/2
> ITEM: Use Vector-enhanced color space conversion
> DESCRIPTION: If checked, YUV 4:2:0 will be converted to UYVY 4:2:2 in
> an Altivec/MMX enabled routine. If unchecked, Quicktime will handle
> the conversion instead.
>
> This smacks of the function you mentioned in your findings. I
> unchecked it and the hiccuping playback ceased entirely. However,
> there was a cost: all picture fidelity went out the tubes. The screen
> was greenish and had something like four side-by-side copies of the
> video playing all scrunched up awkwardly. The video I was testing, by
> the way, was yesterday's HD Heroes.
Haven't seen that in a long time. I thought that was fixed to work
properly when MMX was turned off, I guess not.
On the following screen in the setup menu, there is an option to
"Scale video as necessary". If you turn that off, 1080i video will
play back fine. But, smaller video will be played without being
scaled up to full screen.. 480i will look like a postage stamp.
> Does that help? What do you get when you play with that setting in
> the Frontend?
That helps to confirm more people are seeing this. I am also
interested in hearing more experiences from people trying the
1080/1088 patch to try and figure out when that helps & when it
doesn't.
Thanks,
Todd
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