How Subtitles Switch Streams
When the viewer switches from one subtitle stream to the other, two things must happen
before the second stream’s subtitles appear:
• The subtitle clip currently showing must reach its end. No subtitle actions, including
switching streams and turning subtitles off, can occur until the DVD player finishes
showing the current subtitle clip.
• A clip on the second stream must start. If a subtitle clip on the second stream starts
before the subtitle clip on the first stream ends, it does not appear, and instead, the
next clip on the second stream is the first from that stream to appear.
For most standard subtitles, this happens relatively quickly and the viewer quickly starts
seeing subtitles from the selected stream. At most they might miss one subtitle clip.
These rules become important if you create a long subtitle clip that is the same length
as the track because you will never be able to select it or switch from it. Having a single
long subtitle clip is useful if you want to place a logo in a corner of the image. For this to
work, its subtitle stream must be selected before the long clip starts, and once selected,
you cannot switch it off or switch to a different subtitle stream.
Note: Subtitles that cross chapter markers are automatically split into multiple subtitle
clips at each marker when you build your project.