Interactive Authoring of Multimedia Documents

Authoring multimedia documents invloves the integration of various types of media items coordinated both in time and space. It is an iterative process, and to be effective it requires integration tools that are highly interactive. In addition, effective multimedia authoring demands that the notion of time be made explicit and flexible such that users can define and manipulate the temporal behavior of multimedia documents directly and flexibly if need be. We describe an interactive framework for multimedia authoring we have developed, which provides users with immediate feedback. It is based on the elastic time model, where the temporal behavior of multimedia documents can be handled explicitly yet flexibly. In its implementation (the Isis* authoring system), users directly manipulate time via timebox diagrams, and the system immediately checks the validity of each user interaction providing guidance for recovery in anomalous situations. Users can query various temporal properties of the document and use automatic scheduling mechanisms. These system support tools are based on a fast incremental algorithm we have developed. Using the elastic time model and the system support tools, multimedia documents can be made flexible in the sense that they are adaptable to the needs of many different users and to the changing evironments. (Dept681, Dept662)