Roll-up captions scroll up two to three lines at a time. The top line disappears as a new bottom line appears in sync with the audio. They can be placed at the top, bottom, or about one-third from the bottom of the screen.
Pop-on captions appear and disappear in sync with the audio in blocks of 1-3 lines. The captions can be placed almost anywhere on the screen to avoid covering graphics and faces, and to identify speakers.
