Posted as soon as MPF MC displays have been initialized.
Note that this event is used as part of the internal MPF-MC startup process. In some cases it will be posted before the slide_player is ready, meaning that you CANNOT use this event to post slides or play sounds.
Instead, use the mc_ready event, which is posted as early as possible once the slide player and sound players are setup.
Note that this event is generated by the media controller and does not exist on the MPF side of things.
Also note that if you’re using a media controller other than the MPF-MC (such as the Unity 3D backbox controller), then this event won’t exist.
This event does not have any keyword arguments