A language for the specification of interactive and distributed multimedia applications

This paper describes a model for distributed multimedia applications and a specification language based on this model. The applications involve the composition and synchronization of multimedia objects, and their interaction with the user and the environment. Objects are autonomous entities which have a behaviour, in terms of the set of operations they offer to the environment; the mechanism for synchronization with these objects is based on the communication of typed events. A single mechanism integrates user interaction with run-time control of the distributed system, allowing a natural interplay between them. The language specifies compositions by exploiting the concepts of the model. It captures the characteristics of multimedia interactions using an adaptation of process algebras, and includes a (procedural) functional part to define data structures and to provide consistency checks. The prototype system implemented consists of a compiler which translates the language expressions into a state machine, and a central interpreter which orchestrates the composition and synchronization of the distributed multimedia objects.