duration.m

    // this is called by the internal API when the movie is done loading... we can find the MPItem
    // from the user dictionary, and ask it for its duration (internal api)... we need the duration
    // to find the halfway point
    - (void)_movieDidPreload:sender {
    	NSDictionary *dict = [sender userInfo];
    	id item = [dict objectForKey:@"AVController_Item"];
    	[self prepareCRS:[item duration]];
    	[(id)super _movieDidPreload:sender];
    }