Format-independent scalable bit-stream adaptation using MPEG-21 DIA

Abstract

Part 7 of MPEG-21 entitled digital item adaptation (DIA), is an emerging metadata standard defining protocols and descriptions enabling content adaptation for a wide variety of networks and terminals, with emphasis on format-independent mechanisms. The DIA descriptions provide a standardized interface not only to a variety of format-specific adaptation engines, but also to a fully format-independent adaptation engine for scalable bit-streams. A format-independent engine contains a decision-taking module operating in a semantics-independent manner, cascaded with a bit-stream adaptation module that uses an XML transformation to model the bit-stream adaptation process using parameters derived from decisions made. In this paper, we describe the DIA descriptions that enable such fully format-independent bit-stream adaptation. Universal adaptation engines substantially reduce the adoption costs because the same infrastructure can be used for different types of scalable media, including proprietary and encrypted.