Abstract
This paper proposes a framework for a virtual classroom application based on a Virtual Collaboration System (VCS), which is being developed under the VISNET II Network of Excellence (NoE)1, and discusses adaptation technologies that enable seamless access to classroom sessions while intellectual property and digital rights are managed. The proposed virtual classroom framework enables academic institutions to conduct their collaborative lecture series, to which registered students will be able to attend remotely and interactively over the Internet. Furthermore, the general public may also follow the classroom sessions under certain restrictions imposed by the participating institutions. In order to facilitate seamless access to a heterogeneous audience that is composed of users with various preferences and privileges accessing the classroom sessions over different network infrastructures and using terminal devices with diverse capabilities, context-aware content adaptation is required to meet constraints imposed by the usage context and enhance the quality of the user experience. Thus, this paper describes the concepts and functionalities of a context-aware content adaptation platform that suits the requirements of such multimedia application scenarios. This platform is able to consume low-level contextual information to infer higher-level contexts, and thus decide the need for and type of adaptation operations to be performed upon the content. In this way, it is aimed to meet usage constraints while also satisfying restrictions imposed by the Digital Rights Management (DRM) to govern the use of protected content.

Abstract
MPEG-21 enables content consumers to access and interoperate with a large variety of multimedia resources and their descriptions in a flexible manner. Considering the great heterogeneity that presently exists across the entire multimedia content chain and the growing importance of open standards to facilitate the interoperations across environments, applications and formats, an MPEG-21 Peer was developed to process and present complex multimedia content, represented as MPEG-21 Digital Items. The novelty of the work essentially relies on the adoption of a Web Services architecture, based on a single Digital Items processing core available for all types of terminal devices.

Abstract

Abstract

Abstract
A tool called BITLINKER, that creates partially reconfigurable modules from the bit-streams of individual components is described. It is also capable of performing restricted component placement and interconnect routing between the assembled components. The resulting modules are used in applications that exploit partial dynamic reconfiguration. The tool is integrated in a design flow particularly aimed at dynamically reconfigurable platform field-programmable gate arrays (FPGAs). The associated development design flow and a run-time support system that can be used to manage module activation and data communication are described. Evaluation results obtained with a Virtex-II Pro system are also reported.

Abstract
Consumer audio applications such as satellite radio broadcasts, multi-channel audio streaming and playback systems coupled with the need to meet stringent bandwidth requirements are eliciting newer challenges in parametric multichannel audio coding schemes. This paper describes the continuation of our research concerning the Immersive Soundfield Rendition (ISR) system and the different enhancements in various algorithmic components. The need to maintain a constant bit rate for many applications requires a rate control mechanism. The various strategies utilized in the rate control mechanism are presented. In addition, an innovative phase compensated down-mixing scheme has been incorporated in the ISR system so as to generate a high quality carrier signal. Enhancements have been made to the blind up-mixing scheme and to considerable gains have been made in terms of acoustic diversity. The various enhancements of the ISR system and its performance are detailed. Audio demonstrations are available at http://www.atc-labs.com/isr.