DVD Demystified

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■ Buttons are subpictures, and subpictures go away when the user
presses fast forward or rewind. To avoid this problem with motion
menus or with buttons over the top of video, disable the FF/REW user
operations or refresh the subpictures every few seconds.
■ Temper creativity with good user interface design. Weigh functionality
over aesthetics and experimentation. Frustrated users will head for the
eject button and will never see your avant-garde designs.
Navigation Design
Chapter 12
Navigation is one of the hardest aspects to get right. In addition to the confusion
of “Title” keys, “Menu” keys, and the inconsistency of navigation on
different discs, it’s difficult to balance creativity and playfulness against
ease of use.
When you create the flowchart, identify the effect of important menu
keys at each menu. Clearly indicate where the viewer will go when they
press “Top” (“Title”), “Menu,” or “Return” (“GoUp”). If you have several
menus, use a hierarchical design that the user will be able to intuitively
understand. If you use more than three levels in your hierarchy, try combining
menus to flatten the structure. Keep all selectable features and
options as close to the main menu page as possible, with a minimal number
of button selections. Make it as easy to navigate back up through menus as
to navigate in the down direction.
Understand the difference between the “Top” (“Title”) key and the “Menu”
key. “Top” means “take me to the very top, to the table of contents.” “Menu”
means “take me to the most appropriate menu for where I am.” For multilevel
menu structures, the “Menu” key can be used to go up one level, or the
“Return” key can accomplish this feature. A well-designed disc will program
the “Return” (“GoUp”) function to act somewhat like the back button on a
Web browser. Each time the viewer presses “Return,” they move up one level
until they reach the top (see Figure 12.3). Every remote should include the
three basic navigation keys: “Top” (“Title”), “Menu,” and “Return.” Take
advantage of the intended function of each (see Figure 12.4). 1
1 Unfortunately, some player interfaces, especially on computers, leave out the Top (Title) key or
the Return key. However, the incompetence of some player designers should not cause you to castrate
your disc. The more discs there are that properly use the navigation keys, the sooner players
will be fixed to provide them all. In the meantime, you can overcome the problem by
providing on-screen buttons for navigation. See the following paragraph.