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

[MythTV]

On Oct 9, 2007, at 9:53 PM, Eric Robinson wrote:

>> 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
>

I think of myself as a MythTV contributor.  I have had a few patches  
that have been accepted over the years.

There has been some investigation on the CoreVideo/OpenGL in the  
past. Look in the archives and trac.

I don't think this is a functional bug but a performance issue.  A  
faster machine might solve the problem.

This is one of the items on my list of things to look into if I win  
the lottery and didn't have to work :-)

Sorry I can't be of more help.

Mino