Customized video telephony app development using messenger

Hi there.

Actually I want to develop a video telephony application using available messenger components but I am getting stuck in designing.

I tried to look for appropriate interface among MSN Activity SDK, Windows Messenger COM, and Live Messenger Add-in SDK but it seems they don't provide enough interfaces for my below requirements.

Requirements are:
(1) Renderring part should be open for customization for image processing which is similar to OnDraw() in VC6.
(2) Session is established via messenger to save my time
(3) Input video stream can be specified because I want to specify decorated web camera movie as stream input

If I have to make the app from scratch, what technologies do i need? TAPI & DirectX? Are these what messenger use as well?

Thank you in advance,
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