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: The multimedia metadata community (www.multimedia-metadata.info), wherefrom this book originated, brings together experts from research and industry in the area of multimedia metadata research and application development. The community bridges the gap between an academic research and an industrial scale development of innovative products. By summarizing the work of the community this book contributes to the aforementioned fields by addressing these topics for a broad range of readers.

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.

Abstract: This special issue of the Annals gives a selection of the best papers presented at the MEDICHI 2007 workshop, held in Klagenfurt, Austria. The focus of the workshop centered on the issues of the methodology and didactics of the history of informatics.

Abstract: The talk will address a number of problematic issues in current multimedia technology and try to give some positive answers. The term multimedia is used for a mixture of modalities, at least one of them being continuous. In the center of interest are “natural” videos, taken by cameras.

Abstract: Due to the increasing heterogeneity in the current multimedia landscape, the delivery of multimedia content has become an important issue today. This heterogeneity is not only reflected by a plethora of different usage environments, but also by the presence of multiple (scalable) coding formats. Therefore, format-independent adaptation engines have to be used within a multimedia delivery platform, which are able to adapt the multimedia content according to a certain usage environment, independent of the underlying coding format of the content. By relying on automatically created textual descriptions of the highlevel syntax of binary media resources, a format-independent adaptation engine can be build. MPEG-21 generic Bitstream Syntax Schema (gBS Schema) is a tool that is part of the MPEG-21 Multimedia Framework. It enables the use of generic Bitstream Syntax Descriptions (gBSDs), i.e., textual descriptions in XML, to steer the adaptation of a binary media resource, using format-independent adaptation logic. In this paper, we address the design and performance evaluation of a multimedia delivery platform that relies on gBS Schema-driven adaptation engines. This platform is called MuMiVA; it is a fully integrated, extensible platform for multimedia delivery in heterogeneous usage environments, using streaming technologies. To demonstrate the flexibility of our multimedia delivery platform, we discuss the functioning of two different applications (i.e., exploitation of temporal scalability and shot selection) applied to two different coding formats (i.e., MPEG-4 Visual and H.264/AVC). Keywords— Content adaptation, Content delivery, MPEG-21 gBS Schema, XML transformations.

Abstract: Many activities on the web are driven by high-level goals of users, such as “plan a trip” or “buy some product”. In this paper, we are interested in exploring the role and structure of users’ goals in web search. We want to gain insights into how users express goals, and how their goals can be represented in a semi-formal way. This paper presents results from an exploratory study that focused on analyzing selected search sessions from a search engine log. In a detailed example, we demonstrate how goal-oriented search can be represented and understood as a traversal of goal graphs. Finally, we provide some ideas on how to construct large-scale goal graphs in a semi-algorithmic, collaborative way. We conclude with a description of a series of challenges that we consider to be important for future research.

Abstract: An approach for quality-of-service based replica management in a proxy-to-proxy network is presented. Management decisions are based on a metrics called replication affinity. Replication affinity combines two other affinity metrics we call (1) placement affinity and (2) reallocation affinity. Placement affinity is used to find the best location to enable QoS based media delivery to future clients. Reallocation affinity is used to make media stream replacement decisions in case of insufficient storage space. Using our approach content replacements can be varied in the granularity. Granularity variations are possible for compressed videos by using multiple description coding (MDC). The effect of using replication affinity is evaluated by emulation experiments. For the experiments the network simulator NS-2 has been used.

Abstract: Active and passive replication are powerful techniques to improve the quality of multimedia streaming. Most systems follow either the active or the passive approach. A well known example for active replication are Content Distribution Networks [8] that replicate data to predefined static locations. In contrast to that, P2P file sharing networks [2, 1] use passive replication where identical content is usually provided by different peers. We suggest a system that combines both techniques using Proxy Affinity, Request Affinity and Replication Affinity considering user preferences, user behaviour, hardware resources and networks capabilities.

Abstract: With the advent of Web 2.0 technologies a new attitude towards processing contents in the Internet has emerged. Nowadays it is a lot easier to create, share and retrieve multimedia contents on the Web. However, with the increasing amount in contents retrieval becomes more challenging and often leads to inadequate search results. One main reason is that image clustering and retrieval approaches usually stick either solely to the images' low-level features or their user-generated tags (high-level features). However, this is frequently inappropriate since the "real" semantics of an image can only be derived from the combination of low-level and high-level features. Consequently, we investigated a more holistic view on image semantics based on a system called Imagesemantics. This system combines MPEG-7 descriptions for low-level content-based retrieval features and MPEG-7 keywords by a machine learning approach producing joined OWL rules. The rule base is used in Imagesemantics to improve retrieval results.

Abstract: Due to the increasing performance requirements of decoding H.264/AVC in HDTV or larger resolutions, new approaches are necessary to enable real-time processing. According to the current trend to parallel computation in all performance classes, decoding of AVC must be mapped to these architectures even though this is complicated by the increased complexity and many data dependencies in the codec. We propose and evaluate different ways of using multithreading to speed-up our .NET implemented decoder. While slice based approaches scale best, this is not a flexible approach because of the reliance on specially encoded streams. Functional partitioning and macroblock pipelining prove to be a good alternative for almost all evaluated videos.