To add your own video to a menu background:
Make sure the menu to which you want to add the background video is showing in the iDVD window.
Click the Media button, then click the Movies button so you have access to your movie folders.
Using any of the methods described in step 3, you can also drag a movie file stored elsewhere on your computer instead of from the Movies pane.
Use one of the following methods to add the video to the menu background:
Drag a movie file from the Movies pane to the DVD menu, outside any drop zones. Before you drop the file, press the Command key and choose “Replace background” from the shortcut menu that appears (shown below). Then release the mouse button.
With your pointer over the menu (and with no button or text object selected), press Command-I to open the Menu Info window. Drag a movie file from the Movies pane to the background well (the center well, shown below).
Click the drop zone button (shown below) to open the drop zone editor. Drag a movie file from the Movies pane to the Menu well. An icon that corresponds to the type of movie file you added appears in the well.
If the Menu Info window is not already open, press Command-I. Move the Loop Duration slider to set how long the movie plays before it repeats (or “loops”).
The menu can loop up to the length of the longest media you have added to the menu (for example, a movie or a playlist), with a maximum length of 15 minutes.