First I would like to state that VLC is is a stand alone player and does NOT use or require Windows ActiveX components to run.
So I assume you are asking about VLC's (ActiveX component) interface into windows and or into your browser. Considering this is just another way to call VLC into usage, this component can not ever do more that the program it self can do.
It is my understanding that the DirectX component within VLC has been rebuilt in VLC 0.8.4 and will handel anything DirectX will handel with full backward compatibility (within reason of what VLC is). But this does rely on DirectX automatic functions as there have been added no option controls for over ride (VMR9 to VMR7). Also it depends greatly on the capabilities of your video card and its drivers as to what features the automatic functions of DirectX can pick. Most vendors of Video card have provided features (or over rides) that can be changed according to your taste.
I have found (over time) that changing these generally cause problems in other areas of usage. Also some games make changes or allow you to make changes to these and when you make their changes it causes problems for other programs.
While I have tried to answer your question, I suggest you search Microsoft's web site for related articles on DirectX. Perhaps the More direct approach would work for you, IE tell us what you are Trying to do and perhaps someone hare can help you. Like support for a particular format or playing a particular type of file.
Hope this has been helpful to you!