Apple DVD Studio Pro 4 - Manual (Page 59)

MPEG Encoding and 16:9 Video
It’s important to correctly identify your source video as either 4:3 or 16:9 before encoding
it. At this point, you are only identifying it—you are not defining how it should be handled
when played back. When using the integrated MPEG encoder, you can select the video’s
aspect ratio in the Encoding pane of DVD Studio Pro Preferences.
Using 16:9 Assets in Tracks
Each track within a DVD Studio Pro project has an aspect ratio setting. This setting lets
the DVD player know how to display the video when playing back the title.
With a 16:9 track, 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.
Mixing 16:9 and 4:3 Assets in a Track
Keep in mind that a track’s aspect ratio setting applies to the entire track. If you mix 16:9
assets with 4:3 assets in a track, you will have problems when playing it back. For example,
if you set the aspect ratio to 16:9 Letterbox, the 4:3 video will also be letterboxed and
end up looking vertically compressed.
To be safe, do not mix 16:9 and 4:3 assets in the same track. Instead, create separate tracks
for each. You can use the Connections tab in DVD Studio Pro to control the playback
order of the tracks.
Some Players Cheat!
Unfortunately, not all players handle 16:9 video correctly. The aspect ratio setting for each
track is stored in the track’s video title set file (vts_01_1.vob, for example). Most DVD
players read the setting and process it correctly, but some DVD players ignore this setting
and instead look at the aspect ratio setting of the video itself. For the most part, this works
out, but it can result in inconsistencies when playing the title on different DVD players,
particularly if you are not careful while encoding and authoring.
Buttons over 16:9 Video Tracks
To place a button over a video track, you add a menu overlay to a subtitle stream in the
track. These overlays are not processed in the same way as the video, so you must create
a separate overlay for each display mode (16:9, 4:3 letterbox, and 4:3 pan-scan). You then
need to create a script that selects the correct subtitle stream to display based on the
DVD player’s settings.
See What Happens with Different Aspect Ratios? for information on using subtitle streams
to place buttons over a video track, and see Creating Scripts for information on creating
scripts.
59 Chapter 4 Preparing Video Assets