Composer: Authoring Tool for iTV Programs

This paper presents Composer, an authoring tool to help creating interactive TV programs for the Brazilian Terrestrial Digital TV System. In Composer, several abstractions are defined creating different document views (structural, temporal, layout and textual). One of these views, the temporal view, preserves as much as possible the timeline paradigm, so popular in TV program editing. Using this view, authoring can be done by placing media objects on a time axis, however, preserving the relative relationships among them. Moreover, nondeterministic time events, like viewer interactions and content adaptations, can also be represented in the temporal view. In addition, the occurrence of these unpredictable events can be simulated, and the resulting TV program played, from any starting point. Besides other facilities provided by its four views, Composer also supports third-party views created as add-ons, and live program editing.