[mythtv] Mac OS X video: QuickTime implementation

Nigel Pearson nigel at ind.tansu.com.au
Wed Sep 8 01:40:05 EDT 2004


> Known problems:
>
> - On my PowerBook G4 800, I have frequent "prebuffering pause" and 
> "A/V diverged" problems.  Under v1, I couldn't draw enough frames to 
> trigger the prebuffering error, so I don't know if I did something 
> wrong.  Changing the kPrebufferFrames number alters, but does not 
> cure, the problem.  This is really where I'm stuck; Nigel, does your 
> superior hardware fix the issue?

	Yep. The pointer fix gives me a rock-solid scaled image,
in either thousands or millions of colours. I even tried it
in windowed mode (at 512x384), and was able to move the window
and change the colour depth while it continued playing. Amazing!

	Now, for a really nice touch, having the program icon also
displaying the image (if we are in windowed mode) would be
freaking awesome. But only if you get bored :-)


	I can't quite work out why performance is so bad for you
and Bruce. As long as I am not running the debug version,
even the v1 display code was fast enough for my large stream.
My machine has the latest and greatest, but I thought that
_any_ G4 would have enough hardware acceleration to do at
least scaling, and probably YUV2RGB, in hardware (with v2).

	Will try on my PowerBook G4 400 tonight.


> - There are transparency problems with the OSD overlays - I get yellow 
> instead of transparent areas in both v1 and this version.

	No such problem for me (in either version). I suspect that
you are missing an endianness patch for libs/libmythtv/yuv2rgb.cpp
I will mail (yet another) version of these patches soon.


> - The over/underscan option reacts funny with the OSD overlays; they 
> get drawn too small, unless my scaling is off.  I haven't tried it out 
> on a Linux frontend to see if it's a general issue.

	Haven't had much time to explore this yet, but tried
setting overscan to 50%. OSD did not display in the visible
window, so I tried the I (info) key. It crashed. Similar
results if I tried the W (aspect) key twice.

P.S. Background of display area isn't "blackened" between
      modes when changing aspect.


> What do you think?

	Absolutely fabulous work, Jer.

--
Nigel Pearson, nigel at ind.tansu.com.au | "Reality is that which,
Telstra BI&D, Sydney, Australia       |  when you stop believing
Office: 8255 4222    Fax:  8255 3153  |  in it, doesn't go away."
Mobile: 0408 664435  Home: 9792 6998  |  Philip K. Dick - 'Valis'



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