Abstract: Currently, much research aims at coping with the shortcomings in multimedia consumption that may exist in a user's current context, e.g., due to the absence of appropriate devices at many locations, a lack of capabilities of mobile devices, restricted access to content, or non-personalized user interfaces. Recently, solutions to specific problems have been emerging, e.g., wireless access to multimedia repositories over standardized interfaces; however, due to usability restrictions the user has to spend much effort to or is even incapable of fulfilling his/her demands. The vision of user-centric multimedia places the user in the center of multimedia services to support his/her multimedia consumption intelligently, dealing with the aforementioned issues while minimizing required work. Essential features of such a vision are comprehensive context awareness, personalized user interfaces, and multimedia content adaptation. These aspects are addressed in this paper as major challenges toward a user-centric multimedia framework.

Abstract: This paper introduces aWeb-based guidance system which supports optimized presentations of sights or exhibited objects on different types of available stationary and mobile consumer devices, possibly running different operating systems. This is accomplished by adapting both the objects’ content, as well as their presentation to the current usage context. Content thereby may be encoded in different presentation formats like video, audio, image, and marked-up text. The usage context embraces a set of properties describing the current usage environment of the guide. This includes, for example, the consumer device’s capabilities, its current location, and the user’s preferences. Both, the content adaptation and presentation services are based on standardWeb technologies for increased interoperability. Finally, the guidance system is augmented with a Web-based content management and a statistics module, which enable for remote content administration and usage evaluations, respectively.

Abstract: The adaptation of multimedia resources is a common method to enable the transport and consumption of audio-visual content in constrained environments. An important aspect in this field is adaptation decision-taking, which aims to find adaptation parameters that maximize the quality for the consumer while considering the constraints of the networks and terminals involved. In this paper we focus on improving the adaptation of audio-visual content by maximizing the perceived quality. This can be realized by using a multimedia quality model and content-related metadata. We present an approach to derive this content-related metadata from subjective tests and use it for adaptation decision-taking within the MPEG-21 multimedia framework.

Abstract: The MPEG-21 standard defines a framework for the interoperable delivery and consumption of multimedia content. Within this framework the adaptation of content plays a vital role in order to support a variety of terminals and to overcome the limitations of the heterogeneous access networks. In most cases the multimedia content can be adapted by applying different adaptation operations that result in certain characteristics of the content. Therefore, an instance within the framework has to decide which adaptation operations have to be performed to achieve a satisfactory result. This process is known as adaptation decision-taking and makes extensive use of metadata describing the possible adaptation operations, the usage environment of the consumer, and constraints concerning the adaptation. Based on this metadata a mathematical optimization problem can be formulated and its solution yields the optimal parameters for the adaptation operations. However, the metadata is represented in XML resulting in a verbose and inefficient encoding. In this paper, an architecture for an Adaptation Decision-Taking Engine (ADTE) is introduced. The ADTE operates both on XML metadata and on metadata encoded with MPEG's Binary Format for Metadata (BiM) enabling an efficient metadata processing by separating the problem extraction from the actual optimization step. Furthermore, several optimization algorithms which are suitable for scalable multimedia formats are reviewed and extended where it was appropriate

Abstract: Intelligent, server-side adaptation of multimedia resources is becoming increasingly important and challenging for two reasons. First, the market continuously brings up new mobile end-user devices to which the content has to be adapted as these devices support different display formats and operate on various types of networks. On the other hand, with the help of metadata annotations which are now available in the MPEG-7 and MPEG-21 standard, advanced forms of resource adaptations on the content level become possible. As none of the existing multimedia transformation tools and libraries can support all these different forms of basic and advanced adaptation operations, an intelligent multimedia adaptation server has to integrate such external tools and algorithms and perform an adequate sequence of adaptation operations on the original resource before sending it to the client. In this paper we present the results of the ISO/IEC MPEG core experiment on using Semantic Web Services technology as a tool for declaratively describing the semantics of adaptation services and constructing multi-step adaptation sequences in an open and extensible multimedia adaptation framework. We show how the semantics of adaptation operations can be captured in the form of input, output, precondition, and effects, how the problem of finding adequate adaptation sequences can be viewed as an Artificial Intelligence planning problem, and finally, how the existing MPEG standards are technically integrated into the service descriptions and how they serve as the shared ontology of the domain. Our approach both introduces declarative, knowledge-based technology into the involved multimedia communities and on the other hand broadens the application scope of Semantic Web Service technology in the area of general semantic service descriptions and automated program construction.

Abstract: Universal Plug and Play (UPnP) is a widely accepted standard for automatically detecting devices and services in a local area network as well as for describing and controlling them. In order to deal with multimedia devices and especially content, in 2002 the UPnP-AV standard definition was released. It defines device and service descriptions for Media Servers and Renderers. Thereby, the Media Server’s Content Directory Service allows an easy management and the exchange of metadata about the provided media data. Media content became browsable by semantic meta information about it. There are still two major drawbacks of UPnP-AV, which make its usage in real world multimedia communication scenarios very difficult. First, searching for similar content on distributed Media Servers with a huge number of media files is not economically possible. Second, the media content must be consumed by Renderers as provided by the Servers, independently of their terminal capabilities and network connections. In order to deal with these two drawbacks, this work proposes a novel approach of metadata integration and media transcoding in UPnP networks. First, the Media Server is extended by a Control Point which offers discovery of other Media Servers and fetches metadata from their Content Directories. Furthermore, it integrates the gathered information in its own Content Directory. Control Points are then able to query this Integrating Media Server for a desired content, and get a network-complete search result. Second, terminal and network capabilities of the Render-ers are taken into account in order to transcode and transmit the content in a suitable way for the consuming device. These two approaches of metadata integration and media data adaptation enable searchable logical views on tailored multimedia content in UPnP-AV networks.

Abstract: An adaptive multimedia proxy is presented which provides (1) caching, (2) filtering, and (3) media gateway functionalities. The proxy can perform media adaptation on its own, either relying on layered coding or using transcoding mainly in the decompressed domain. A cost model is presented which incorporates user requirements, terminal capabilities, and video variations in one formula. Based on this model, the proxy acts as a general broker of different user requirements and of different video variations. This is a first step towards What You Need is What YouGet (WYNIWYG) video services, which deliver videos to users in exactly the quality they need and are willing to pay for. The MPEG-7 and MPEG-21 standards enable this in an interoperable way. A detailed evaluation based on a series of simulation runs is provided.

Abstract: The focus of the workshop has been laid on the issues of the methodology and didactics of the history of informatics. A special interest has been devoted to contributions which document some aspect of Austria’s role in the field of informatics, or provide insight into the impact of informatics on the Austrian society. Informatics (computer science) is a thriving science yet its brief history is barely credited as an academic discipline. The existing body of historical literature, while small, includes some brilliant contributions, especially biographical and technological chronicles, as well as some excellent anecdotal treatments. Nevertheless, the methods and didactical approaches for examining the history of informatics are poorly developed; the number of conferences and journals dealing with these issues is few, as is the number of young scientists doing scientific research on the history of informatics. This is not because these topics are uninteresting or irrelevant; rather, the conditions for methodically well-founded research are lacking. The motivation of MEDICHI 2007 has been to contribute towards making the ‘history of informatics’ an accepted science and a valued component of Informatics education and research. Each submitted paper has been reviewed by 3 members of the program committee. From 12 submitted papers, 8 have been accepted as a full and 2 as a short paper to be presented. Additionally, 5 invited position papers, written by members of the program committee and 4 invited keynote talks have been presented in altogether 8 sessions. Each presentation is published in the proceedings at hand. The MEDIHCI 2007 workshop was also the venue for awarding the prizes of the 2007 Wolfgang von Kempelen Prize for Computing Science History. The organizers thank to all participants for their contributions and wish the reader an exiting tour through the proceedings