The First-Play PGC of the supplied DVD project contains two virtual pre-commands:

1) Mov GPRM1, 0 (Initialize the contents of General Parameter Register 1 to 0).
2) JumpTT 1 (Jump to title 1) that begins the playback of the video title 1.

The first virtual command is added to initialize and support the operation of the Angle menu. The Angle menu has two menu items: "Continuous" and "Return to menu". If the menu item "Continuous" is selected, playback is resumed and the disc is played continuously, playing title 1 and title 2, and automatically repeat by going back to title 1. Setting the contents of the general parameter register GPRM1 and performing the appropriate branching to a predefined menu based upon the contents of the GPRM1 accomplish this operation. At first play, we initialize the contents of GPRM1 to 0 so that the default playback behavior is continuous playing. The menu items in the Angle menu sets the contents of GPRM1 to 0 or 1 when "Continuous" or "Return to menu" is chosen, respectively. At the end of each title, if GPRM1 is 1, the appropriate video title set menu (root menu or chapter menu) is displayed. Otherwise, the next title is played back. The following flowchart explains how the virtual commands work.