Subtitling - Subtitling Types

The FAB Subtitling System supports the following types of subtiting:

Open subtitles are put into the TV picture already at the TV station before the TV signal is transmitted. This procedure enables the viewers to see subtitles without the need for using a special decoder in the TV set. However this way only one language can be transmitted at a time. By trying to transmit more languages a very large part of the TV picture would be covered by the subtitles.

Teletext subtitling is used to transmit subtitles as teletext data in the hidden part of the TV picture. This kind of subtitling is mainly used in Europe. Teletext data is decoded by the teletext decoder in the TV set and displayed on the TV screen. This way it is possible for each viewer to decide whether he wants to see subtitles or not. In case he wants to read the subtitles he simply selects the subtitles page on the teletext decoder and the subtitles will be displayed over the TV picture. By selecting between different teletext page numbers it is also possible to define the language which should be displayed on the screen.

DVD, HD-DVD & Blu-ray subtitles are similar to teletext subtitles which means that they are not recorded into the visible part of the TV picture but onto a separate track of the DVD disk. The DVD player will read the subtitles from the separate track and overlay the subtitles over the picture. Because there are many subtitle tracks available on one DVD it is possible to record subtitles in multiple languages onto a single DVD disk.

DVB subtitling is similar to teletext subtitling. DVB subtitles are transmitted as bitmap data (not overlaid over the video) in the DVB signal and the DVB set top box decoder decodes subtitles and displays them over the video.