[mythtv-users] Mac OS X choppy playback at high display resolutions, such as 1080p

Eric Robinson ryunokokoro at gmail.com
Wed Oct 10 04:53:53 UTC 2007


> I did some quick testing.  It looks like that anytime that the image
> needs to be transformed (offset or scaled) it causes a problem so the
> patch wouldn't solve the problem if you set an overscan or offset.
>
> I don't know of an easy solution that will allow overscan or offset
> without using the QuickTime transform function which seems to be
> causing the problem.
>
> The most likely solution would probably be to move to a CoreVideo/
> OpenGL based VideoOutput class that could utilize the GPU for the
> transformation.

Ahh, so the problem lies in the QuickTime transform function.
Conceivably, though admittedly unlikely, Apple could update QuickTime
and fix the slow speed...?

The other option sounds like a major shift in the way the video is
processed on the Mac.  Mino, are you a MythTV developer?  Is that
something that is plausible?  Should this be marked as a bug (as 1080p
TVs get more common this will likely affect a lot of people...)?

Thanks for all the help.

- Eric


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