Using 16:9 Assets in Menus
Typically you’ll want to use 16:9 menus with 16:9 tracks. Most of the same concerns with
video apply to menus as well—specifically how the 16:9 menu is displayed on a 4:3
monitor.
With a 16:9 menu, you specify how it will play back on a 4:3 monitor: Pan-Scan, Letterbox,
or Pan Scan & Letterbox (allowing the viewer to choose). As mentioned previously,
pan-scan is rarely used, and should never be selected unless the encoded video contains
pan-scan vector information.
See
Understanding Pixel Differences in Graphics and Video
for information on the image
size settings you should use when creating 16:9 menus.