Anyone worked with VB and Windows Media Player OCX?

I'm trying to find out how to detect whether a media stream contains a video
signal.  I've searched the microsoft site and found about everthing else I'd
ever want to know about Windows Media Player except how to detect a video
signal.

If you know how, please let me in on the big secret.  If you know of a
source of info that might give me the answer, let me know that too.

Respond by email if possible.

Thanks,

Doug Williams