User Guide

204 Chapter 13, Navigation Commands
About Navigation Commands
Navigation commands placed at various locations in a scenario direct playback to jump from
one location to another and provide instructions that tell the DVD player whether and how
to change playback flow and characteristics.
With navigation commands you can:
• Send playback to any location in the scenario.
• Change playback characteristics for audio and video material.
• Reconfigure settings for the DVD player.
• Define fixed branching (playback flow that cannot vary).
• Define conditional branching (playback flow that can vary depending on system
variables and viewer input) based on fixed values or variables.
The DVD Specification restricts playback to certain paths. Playback can proceed from a VMG
to a VTS, title, or language folder (domain), and from either a title (through an Entry PGC)
or language folder to a chapter. Playback cannot flow directly from one VTS to another but
must be routed through a dummy PGC in the VMG.
With the Scenario Editor and Simulation window, you can place and define multiple and
conditional sets of navigation commands in the Pre, Post, Cell, and Btns (menu) command
areas within a PGC, which are indicated by flags on the PGC, program, cell, and menu icons
in the Scenario Editor.
Following is a brief description of each command area:
Pre Executes the command before the PGC plays.
Post Executes the command after the PGC plays.
Cell Executes the command after the cell plays.
Btns Links a menu button to a title folder, menu, title, or chapter.