[plt-scheme] libVLC and PLT Scheme on OSX

I'm trying to do some video playback inside a PLT Scheme window on a
Mac with OSX.  I'm using libVLC to do the actual video playback and
I've been able to get it work in Windows using combination of
libvlc_media_player_set_hwnd on the VLC side, and get-handle on PLT
side to get an hwnd of a window.

On the mac, the VLC documention says that it needs an "agl handler" in
the form of a uint32_t.  According to the documentation, get-handle
returns a WindowRef or ControlRef on osx, which doesn't work.  After
some reading, it looks like an agl handler might be related to OpenGL,
so I thought the agl handler might be something I could retrieve using
a gl-context%, but I don't know how i could coerce that into a 32 bit
integer.

Anybody have any ideas as to what I could be looking for?

Thanks.

P.S. If anyone is interested in what I am doing, I have a blog post
that shows code for doing the video playback under Windows:
http://cwbowron.wordpress.com/2009/11/20/vlc-and-plt-scheme-n1/

-- 
Christopher W. Bowron <chris at bowron.us>
[ Nothing is exciting if you know what the outcome will be ]
    - Joseph Campbell