Timed text

Timed text is the presentation of a text medium in synchronization with other media, e.g. B. audio or video.

Typical applications of Timed Text are e.g. B. Real-time subtitling of foreign language films on the Internet, subtitles for users without audio devices or the hearing impaired , karaoke , treadmills with news or teleprompter applications.

Timed text for MPEG-4 films and cell phone media is described in MPEG-4 Part 17 and is referred to in RFC 3839 .

The W3C is developing a Timed Text ( TT ) specification that includes many aspects of Timed Text on the Internet. It was introduced as a W3C recommendation.

The question of developing an interoperable text format came up during the development of the SMIL 2.0 specification. Today there are quite a few incompatible formats for image text, subtitling, and other timed text formats used on the web. This means that when creating a SMIL presentation, the text part often has to be routed to a specific playback environment. This poses a problem in creating interoperable SMIL presentations. In addition, the hearing impaired are very dependent on subtitles to make audiovisual content accessible to the hearing impaired viewers. The lack of an interoperable format adds significant additional cost to the already high cost of subtitling Internet content.

Timed Text enriches the user experience of services that are connected to Timed Text and is used as an important stimulus e.g. B. used in the use of captioning and subtitling. Among the organizations that want to work on Timed Text are e.g. B. Streaming media technologies, web browser companies, representatives of the hearing impaired community, producers of subtitles and manufacturers of consumer electronics.

Web links

• W3C 's Synchronized Multimedia Activity Statement
• The W3C Timed Text homepage