Hello Arman,
Why would you want to add video to the Moodle chatroom, which is, as the name indicates, a chatroom. If you are going to install Red5 in your server, then you could also install OpenMeetings in the server and then network it with Moodle via the OpenMeetings activity plugin. Then teachers can open OpenMeetings (video)conference rooms from their Moodle course and students in the couse can enter those OpenMeetings rooms from Moodle much like they would join a Moodle chatroom. The OpenMeetings videoconference rooms have a chat option, video and audio and in addition to that a whiteboard, file upoad and sharing and they also allow screen sharing and recording of the sessions.
Rgrds,
Paul.