Delivering object-based audio-visual services

Delivery of audio-visual objects differs from the traditional video on demand systems in the characteristics of the presentations delivered. Video on demand has mainly been about delivering MPEG-2 audio and video. In the case of object based presentations such as MPEG-4 presentations, the media data and the media composition data are transmitted to a client as separate streams, typically with different QoS requirements, in the same session. Furthermore, as the number of objects in a presentation can be quite large, the overhead required to manage the session is large. Interactivity makes this problem more complex as the resources required for a session will now depend on the user behavior, especially when user interaction with objects changes the number of objects in the scene either by adding or deleting objects. In this paper, we present our work on delivering audio-visual services based on MPEG-4. The issues covered include object-based audio-visual (MPEG-4) servers, object scheduling, and content creation.