Video Calling/Conference API for iPhone

Currently am doing project on Family Business. In that I need some video calling sort of thing.

Is there any API available for video conference (or) Any O开发者_JAVA技巧pen Source is available?

Thanks In Advance

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Take a look at the iDoubs project. It is a full feature SIP/IMS phone with various audio/video capabilities. Note that the project is under GPL license.