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

[scram69]

On Mon, Oct 29, 2007 at 4:53 PM, Eric Robinson <ryunokokoro at gmail.com> wrote:
> On 10/10/07, Eric Robinson <ryunokokoro at gmail.com> 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
>>
>
> As can be seen above, it appears that falling back on QuickTime based
> functions for image scaling when (VerticalScreenPixels >= 1080) AND
> (VerticalVideoPixels == 1080) causes hiccuppy gameplay. In Mac OS
> 10.4.x at least.
>
> We now have a new version of OSX to test on, however, with purportedly
> updated video libraries (?).  Has anyone tested this scenario on
> Leopard (Mac OS 10.5.x)?  Is the problem still present?
>
Dredging up this old thread as I finally got around to upgrading to 10.5.

Under 10.4.11, using 0.21 OSX universal frontend (not -fixes), I used
a 1% "overscan" or scaling in the playback settings to remove "bars"
and black/white noise from around the edge of the playback (displaying
onto 720p plasma).

When I tried the same 1% overscan under 10.5.5, using 0.21-fixes
(18900 weekly build), playback really suffers.  I'm using a 2.0 GHz
core2duo mini.

Has anyone had success using scaling to slightly overfill their
display under 10.5/0.21-fixes?