Distributed Multimedia QoS Parameters from Presentation Modelling by Coloured Petri Nets

In this chapter we address the problems associated with storing and retrieving multimedia presentations where the multimedia objects making up the presentation are stored in a distributed manner on a network of computers. In order to deliver multimedia presentations to users in an efficient manner, quality of service (QoS) parameters for various components like networks, disks, etc, need to be defined before a multimedia presentation is launched. It is our hypothesis that a multimedia presentation authoring tool should use an internal representation known as a coloured petri net, in order to represent the synchronisation and the spatial aspects of a multimedia presentation. The CPN representation for a presentation would be represented internally only and need not be visable. In this chapter we outline how some commonly used multimedia sychronisation features can be represented using CPNs and we discuss what kinds of persistent storage would be needed for this.