[mich at jamby.net: Re: Questions about QuickTime]

[Florian G. Pflug]

This was the anyser of the guy who wrote a divx-decompressor for OSX

----- Forwarded message from Michael Stuurman <mich at jamby.net> -----

There is a yuv component in OSX 10.0.4 but it not so fast (for instance 
k2vuyPixelFormat)
I think the best is to wait for 10.1 and use the undocumented y420, 
which is a planar component.
I took us some time find out how to use it, it's kind of weird.
It also gets rid of a big frame copy, because it is constructed planar
It is very fast in fullscreen mode and slows down when you put for 
instance the sound icon in front of it in 10.1. So yes I think it is an 
yuv overlay in fullscreen mode. (It's also running smooth on th new PB 
400Mhz (firewire) but it is a bit shaky on the old PB 400 Mhz, which is 
I think due to the different graphic cards).

You can just download the src at:
http://wolk.datashed.net/gems/mich/qtffmpeg.src.tgz
and  look at ff_Codec.c

>If there is overlay support in OSX 10.0.4, do I have to do anything 
>special
>apart from calling DecompressSequenceBeginS / DecompressSequenceFrame 
>to use
>it?

I'm just a QT component and tell the System he, I'm outputting y420 can 
you eat that?
I suppose you can do the same from an application.


Hope it Help,

Michael Stuurman



----- End forwarded message -----

The y420-codec in 10.1 looks promising. Can't wait to get my hands on 10.1
to try it out.

greetings, Florian Pflug