Abstract: The multimedia community is pursuing, among others, the vision of Universal Multimedia Access (UMA). UMA denotes the concept that any multimedia content should be available anywhere, anytime, on any device, tailored to the user's needs and preferences, accessible for the user in a transparent and convenient way. Key to achieving this vision is to realize collaborative adaptive behavior of the involved distributed multi-media system components (server, media-aware net-work elements like proxies or gateways, and clients), based on intense metadata exchange and multimedia content negotiation, adaptation, or personalization. This paper outlines the key challenges and the state of the art in achieving such adaptive behavior. The major challenges have been tackled recently and many of the building blocks of UMA have become or are becoming available from standardization groups, which are instrumental in this area to ensure interop-erable use of the media and metadata items. However, making use of these standards in practical multimedia systems raises additional issues, both of conceptual nature and in terms of implementation. Based on years of contributions to ISO/IEC MPEG standardization efforts and of research work into adaptive multimedia systems, we will give an overview of these challenges, discuss the state of the art, and introduce an emerging principled solution for format-independent multimedia content adaptation.

Abstract: In this paper, an interoperable streaming framework for the adaptation and streaming of scalable multimedia content is presented. The streaming framework’s architecture for Video on Demand (VoD) as well as multicast streaming is presented. The VoD test-bed allows each client to set up a separate streaming session and receive the bitstreams in a quality tailored to the clients requirements, while the multicast test-bed provides a layered scalable multicast to all clients and every client needs to decide which layers to subscribe to. After the description of the architectures, a comparison in terms of performance of the MPEG-21 DIA metadata-based adaptation approach to an SVC-specific adaptation approach is presented. Furthermore, optimizations for both adaptation approaches are presented and the performance improvements due to the optimizations are discussed.

Abstract: This paper presents an interoperable framework for the streaming of scalable multimedia content such as Scalable Video Coding (SVC). In particular, the framework’s architecture for both, Video on Demand (VoD) and multicast streaming, is presented. The architecture includes a detailed description of the adaptation engine – conforming to MPEG-21 Digital Item Adaptation – as well as the integration of the adaptation engine into VideoLAN’s VLC media player, which provides the streaming server and client for the framework. Following the description of the architecture, a comparison in terms of performance of the generic MPEG-21 DIA-based adaptation approach, which is utilized by the described demo, versus an SVC-specific adaptation approach is presented and possible further improvements for both approaches are investigated.

Abstract: In this paper we present an interoperable multimedia delivery framework for scalable video coding based on MPEG-21 Digital Item Adaptation (DIA). In can be used to transmit scalable video contents within heterogeneous usage environments where the properties of the usage environment (e.g., terminal/network capabilities) may change dynamically during the streaming session. The usage environment is signaled by interoperable description formats provided by the DIA standard. Additionally, the adaptation itself is done by exploiting the standard's generic adaptation approach, i.e., independent of the actual coding format. Thus, the overall framework is also applicable for other scalable coding formats.

Abstract: This paper provides a performance analysis of adaptation approaches designed for scalable media resources. In particular, we investigate the streaming of media resources compliant to the Scalable Video Coding (SVC) extensions of Advanced Video Coding (AVC)within heterogeneous environments, i.e., terminals and networks with different capabilities. Therefore, we have developed a test-bed in order to analyze two different approaches for the adaptation of scalable media resources, namely a generic approach that is applicable independently of the actual scalable coding format used and a specific approach especially built for SVC.The results show that if adaptation is required the generic approach clearly outperforms the approach specifically built for SVC

Abstract: Current trends in smart homes suggest that several multimedia services will soon converge towards common standards and platforms. However this rapid evolution gives rise to several issues related to the management of a large number of multimedia streams in the home communication infrastructure. An issue of particular relevance is how a context acquisition system can be used to support the management of such a large number of streams with respect to the Quality of Service (QoS), to their adaptation to the available bandwidth or to the capacity of the involved devices, and to their migration and adaptation driven by the users' needs that are implicitly or explicitly notified to the system. Under this scenario this paper describes the experience of the INTERMEDIA project in the exploitation of context information to support QoS, migration, and adaptation of multimedia streams.