Knowledge-based multimedia adaptation for ubiquitous multimedia consumption

Intelligent, server-side adaptation of multimedia resources is becoming increasingly important and challenging for two reasons. First, the market continuously brings up new mobile end-user devices to which the content has to be adapted as these devices support different display formats and operate on various types of networks. On the other hand, with the help of metadata annotations which are now available in the MPEG-7 and MPEG-21 standard, advanced forms of resource adaptations on the content level become possible.As none of the existing multimedia transformation tools and libraries can support all these different forms of basic and advanced adaptation operations, an intelligent multimedia adaptation server has to integrate such external tools and algorithms and perform an adequate sequence of adaptation operations on the original resource before sending it to the client.In this paper we present the results of the ISO/IEC MPEG core experiment on using Semantic Web Services technology as a tool for declaratively describing the semantics of adaptation services and constructing multi-step adaptation sequences in an open and extensible multimedia adaptation framework. We show how the semantics of adaptation operations can be captured in the form of input, output, precondition, and effects, how the problem of finding adequate adaptation sequences can be viewed as an Artificial Intelligence planning problem, and finally, how the existing MPEG standards are technically integrated into the service descriptions and how they serve as the shared ontology of the domain.Our approach both introduces declarative, knowledge-based technology into the involved multimedia communities and on the other hand broadens the application scope of Semantic Web Service technology in the area of general semantic service descriptions and automated program construction.