Bug 166403

Can you describe how the feature is supposed to work?

Certainly:

iChat Theater allows users to share any file that is supported by Quick Look, including photos, Keynote presentations, and movies over a video chat session.

http://developer.apple.com/documentation/AppleApplications/Conceptual/InstantMessageProgGuide/Articles/UsingiChatTheater.html

iChat Theater allows applications to send additional audio and video tracks during an AV chat. You can use any NSView as a prebuilt video source or provide the auxiliary video through periodic callbacks for individual frames. Audio is provided through an audio device and channels.

Before implementing a video source, you should select the buffer type—a pixel buffer or an OpenGL buffer—that is most efficiently filled by your application during a callback. The pixel buffer is filled in the main memory—by the CPU rather than the GPU. If you are rendering content using OpenGL, then you typically use the OpenGL buffer.

There are several steps involved in using iChat Theater in your application:

   1. Set the video data source and any video options.
   2. If you are not using an NSView object as the video source, implement the callbacks that provide individual video frames.
      If you're using pixel buffers, implement the pixel buffer methods using Core Video. If you're using OpenGL, implement the OpenGL methods.
   3. Create audio channels and manage them using Core Audio.
   4. Use the start and stop methods to control the video playback.
   5. Register for state change notifications.
      You must register for notifications to establish a connection to iChat Theater.

Dear user, unfortunately Kopete is no longer maintained.

Please migrate to another solution, e.g. for Jabber a possibility is Kaidan, for Matrix a candidate is NeoChat.