How make video call with ejabberd ( like msn and skype ) ?
ejabberd doesn't handle audio/video natively. Audio and video is handled through the Jingle (XEP-0166), which is client-to-client.
If you want to place audio or video calls you should make sure both clients support Jingle through normal serivce discover means (see section 11 of XEP-0166). There aren't a lot of clients that do this right now, but Psi, at least, supports it in more recent builds.