@Article{Devillers2005, author = {Devillers, Sylvain and Timmerer, Christian and Heuer, Jörg and Hellwagner, Hermann}, journal = {IEEE Transactions on Multimedia}, title = {Bitstream Syntax Description-Based Adaptation in Streaming and Constrained Environments}, year = {2005}, month = jun, number = {No. 3}, pages = {463-470}, volume = {Special Issue on MPEG-21, Vol. 7}, abstract = {The seamless access to rich multimedia content on any device and over an network, usually known as Universal Multimedia Access, requires interoperable description tools and adaptation techniques to be developed. To address the latter issue, MPEG-21 Digital Item Adaptation (DIA) introduces the Bitstream Syntax Description (BSD) framework, which provides tools for adapting multimedia content in a generic (i.e., coding format independent) way. The basic idea is to use the eXtensible Markup Language (XML) to describe the high-level structure of a binary media bitstream, to transform its description (e.g., by means of eXtensible Stylesheet Language Transformations, XSLT), and to construct the adapted media bitstream from the transformed description. This paper presents how this basic BSD framework, initially developed for non-streamed content and suffering from inherent limitations and high memory consumption of XML-related technologies such as XSLT, can be advanced and efficiently implemented in a streaming environment and on resource-constrained devices. Two different attempts to solve the inherent problems are described. The first approach proposes an architecture based on the streamed processing of SAX (Simple Application Programming Interface for XML) events and adopts STX (Streaming Transformations for XML) as an alternative to XSLT, whereas the second approach breaks a BSD up into well-formed fragments called Process Units (PUs) that can be processed individually by a standard XSLT processor. The current status of our work as well as directions for future research are given.}, address = {Piscataway, USA}, language = {EN}, pdf = {https://www.itec.aau.at/bib/files/Bitstream Syntax Description-based Adaptation in Streaming and Constrained Environments.pdf}, publisher = {IEEE} }