[mythtv-users] 0.24 Mac OS X Build

[Nigel Pearson]

On Thu, 10 Mar 2011, TJ Harris observed:

> - Top CPU user in both 1080i and 720p was mmx_i420_2vuy  color
> conversion.  Kind of surprising that it isn't done in hardware.


Used to be. In late 2004, Jeremiah worked out how to get QuickTime
to do it in hardware, and the code was in there until late 2006,
when Mac OS X moved from PPC to Intel hardware.


The Intel QuickTime code crashed when fed YUV420 data.
I created an Apple bug ID (4731762), but never got time
to prove the bug to them. In the end, it was much
easier to remove the QuickTime colour conversion.
(made the code simpler, and any Core Duo CPU had
 ample grunt to SW convert). Haven't re-visited that bug.



Not sure how OpenGL does it.


> - nvChannel::waitForTimeStamp  was present on both, but much higher
> CPU usage at 720p (2.8% vs 0.8%)

Hmmm. I don't know what is invoking that (not our code).


Does running an external (CRT?) display
at different refresh rates affect this?

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