[81] | Christian Timmerer, Thomas DeMartini, Hermann Hellwagner, The MPEG-21 Multimedia Framework: Conversions and Permissions, In D A CH Security 2006 (Patrick Horster, ed.), IT Security & IT Management, Düsseldorf, pp. 225-235, 2006.
[bib] [pdf] [abstract]
Abstract: In the area of multimedia computing and communication, one of the major objectives currently being pursued is Universal Multimedia Access (UMA), i.e., enabling users to transparently access any kind of content from anywhere, anytime, with any device. In the course of the MPEG-21 (Multimedia Framework) activities, the ISO/IEC MPEG standardization group has created essential building blocks toward this goal, mainly metadata standards. Two of them are worth noting here: (1) the Digital Item Adaptation (DIA) specification, including normative vocabulary and formats to describe the multimedia consumption context (device, network, natural environment characteristics, user preferences) and to steer media adaptation operations required for UMA; (2) the Rights Expression Language (REL) and Rights Data Dictionary (RDD) specifications, providing terms and a language to express permissions on the usage of the media (who, how, what, under which conditions). In this paper, we describe a recent MPEG-21 DIA Amendment in this area, specifying description formats for: (1) multimedia conversion capabilities, which tool or service providers may use to normatively specify the media adaptation (conversion) capabilities of their tools or services, respectively; (2) permissions and conditions for multimedia conversions, which can be utilized by content providers to determine which adaptations (changes) are permitted on their contents under what conditions. The latter description format embeds media adaptation descriptions into rights expressions, filling a gap between DIA and REL/RDD. In the paper, a use case illustrating a complex UMA scenario justifies the need for these descriptions. Exemplary conversions and permissions descriptions that apply to this use case as well as detailed explanations will be given in the main portion of the paper.
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[80] | Peter Schojer, Laszlo Böszörmenyi, Hermann Hellwagner, QBIX-G- A Transcoding Multimedia Proxy, In Multimedia Computing and Networking 2006 (Surendar Chandra, Carsten Griwodz, eds.), SPIE, San Jose, pp. 60710C-1 - 60710C-16, 2006.
[bib] [abstract]
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 and transrating in the decompressed domain. A cost model is presented which incorporates (1) user requirements, (2) terminal capabilities, and (3) 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 You Get” (WYNIWYG) video services, which deliver videos to users in exactly that 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. Based on the simulation results, the algorithms were integrated into our “Quality Based Intelligent Proxy”, the evaluation of which is in progress.
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[79] | Peter Schojer, Laszlo Böszörmenyi, Hermann Hellwagner, QBIX-G-A Transcoding Multimedia Proxy, Technical report, Institute of Information Technology (ITEC), Klagenfurt University, no. TR/ITEC/05/2.11, Klagenfurt, Austria, pp. 24, 2006.
[bib] [abstract]
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 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 You Get (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.
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[78] | Martin Santner, Roland Tusch, Michael Kropfberger, Laszlo Böszörmenyi, Hermann Hellwagner, Ein Ortserkennungssystem für mobile Touristenführer, In D•A•CH Mobility 2006 (Patrick Horster, ed.), IT Security & IT Management, Ottobrunn, München, Deutschland, pp. 84-98, 2006.
[bib] [abstract]
Abstract: - Location-Based Services - Ortserkennungstechnologien - Ortserkennungsmiddleware - Integration in mobile Anwendung - Automatisiertes Führungssystem.
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[77] | Michael Ransburg, Renaud Cazoulat, Benoit Pellan, Cyril Concolato, Saar De Zutter, Chris Poppe, Andreas Hutter, Hermann Hellwagner, Rik Van de Walle, Dynamic and Distributed Adaptation of Scalable Multimedia Content in a Context-Aware Environment, In Proc. of the European Symposium on Mobile Media Delivery (EuMob 2006) (2006 EuMob, ed.), --, Alghero, Italy, pp. 1-5, 2006.
[bib] [pdf] [abstract]
Abstract: The seamless access to rich multimedia content on any device and over any network, usually known as Universal Multimedia Access, requires interoperable description tools and adaptation techniques to be developed. To address this, MPEG-21 introduces an adaptation framework, which provides several mechanisms for making adaptation decisions according to usage environment and adapting multimedia contents in a coding format independent way. This paper gives an overview of the European FP6 project DANAE which not only implements and extends the existing MPEG-21 adaptation mechanisms but also kicked off several new standardization activities in the area of dynamic and distributed adaptation and resource conversion. MPEG-21 DIP enables static stream selection which is a first step in a series of adaptations. The existing BSD-based adaptation mechanisms enable the efficient implementation of generic adaptation engines, which can be used for existing and future coding formats. These mechanisms were extended to enable dynamic and distributed adaptation. Alternatively to the BSD-based adaptation, resource conversion was investigated which does not rely on scalable media and allows adaptations at the scene level.
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[76] | Martin Prangl, Hermann Hellwagner, Tibor Szkaliczki, Fast adaptation decision taking for cross-modal multimedia content adaptation, In Proceedings oft the IEEE International Conference on Multimedia and Expo (ICME) (Guan Ling, Zhang Hong-Jiang, eds.), IEEE Press, Toronto, Canada, pp. 137-140, 2006.
[bib] [pdf] [abstract]
Abstract: In order to enable transparent and convenient use of multimedia content across a wide range of networks and devices, content adaptation is an important issue within multimedia frameworks. The so called Digital Item Adaptation (DIA) standard is one of the core concepts of the MPEG-21 framework that will support the adaptation of multimedia resources according to device capabilities, underlying network characteristics, and user preferences. Most multimedia adaptation engines for providing Universal Multimedia Access (UMA) scale the content with respect to terminal capabilities and resource constraints. This paper focuses on the cross-modal adaptation decision taking process considering the user environment and terminal capabilities as well as resource limitations on the server, network, and client side. This approach represents a step toward increased Universal Multimedia Experience (UME). Based on four different algorithms for solving this optimization process, we present an evaluation of results gained by running their implementations on different test networks.
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[75] | Martin Prangl, Christian Timmerer, Hermann Hellwagner, Real-time DVB based MPEG-21 Digital Item Adaptation for live Universal Multimedia Access, In Proceedings ELMAR 2006 (Mislav Grgic, Sonja Grgic, eds.), Croatian Society Electronics in Marine - ELMAR, Zadar, Zadar, pp. 297-300, 2006.
[bib] [pdf] [abstract]
Abstract: In order to enable transparent and augmented use of multimedia content across a wide range of networks and devices, content adaptation is an important issue within multimedia frameworks. In this paper, we present a prototype application that receives Digital Video Broadcast (DVB) TV streams on a PC, transcodes the streams on the fly according to the individual User requirements and packs the adapted content together with available metadata into a standard compliant MPEG-21 Digital Item (DI). In this form, the framework enables the live Universal Multimedia Access (UMA) scenario where the DVB content can be transparently accessed by clients such as PCs and PDAs, anytime and anywhere.
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[74] | Martin Prangl, Hermann Hellwagner, Tibor Szkaliczki, A Semantic-based Multi-modal Utility Approach For Multimedia Adaptation, In Proceedings of the 7th International Workshop on Image Analysis for Multimedia Services (WIAMIS) (Izquierdo Ebroul, Kim Hyoung Joon, eds.), WIAMIS Eigenverlag, Incheon, Korea, pp. 67-70, 2006.
[bib] [pdf] [abstract]
Abstract: Content adaptation is an important issue of multimedia frameworks in order to achieve Universal Multimedia Access (UMA), that is, to enable consumption of individual multimedia content independently of the given resource limitations, terminal capabilities and user preferences. The Digital Item Adaptation (DIA) standard, one of the core specifications of the MPEG-21 framework, supports content adaptation considering a wide range of networks, devices and user preferences. Most adaptive multimedia frameworks enabling this UMA do not consider utility aspects in their adaptation decisions. This paper focuses on a generic multi-modal utility model for DIA, enabling increased multimedia experience to the client. Our proposed model is able to take the semantic and the perceptual features of the content as well as the clients individual utility aspects into consideration. Based on a detailed analysis of these constraints we will show how the model reacts on individual input data. Finally we will discuss results of the multi-modal decision taking process according to a few use case scenarios as well.
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[73] | Martin Prangl, Hermann Hellwagner, Horst Bischof, Tibor Szkaliczki, Realtime automatic metal extraction of medical x-ray images for contrast improvement, In Proceedings of the SPIE Symposium on Medical Imaging 2006 (Joseph M Reinhardt, Josien P W Pluim, eds.), SPIE, San Diego, pp. 8, 2006.
[bib] [pdf] [abstract]
Abstract: This paper focuses on an approach for real-time metal extraction of x-ray images taken from modernx-ray machines like C-arms. Such machines are used for vessel diagnostics, surgical interventions, as well as cardiology, neurology and orthopedic examinations. They are very fast in taking images from different angles. For this reason, manual adjustment of contrast is infeasible and automatic adjustment algorithms have been applied to try to select the optimal radiation dose for contrast adjustment. Problems occur when metallic objects, e.g., a prosthesis or a screw, are in the absorption area of interest. In this case, the automatic adjustment mostly fails because the dark, metallic objects lead the algorithm to overdose the x-ray tube. This outshining effect results in overexposed images and bad contrast. To overcome this limitation, metallic objects have to be detected and extracted from images that are taken as input for the adjustment algorithm.In this paper, we present a real-time solution for extracting metallic objects of x-ray images. We will explore the characteristic features of metallic objects in x-ray images and their distinction from bone fragments which form the basis to find a successful way for object segmentation and classification. Subsequently, we will present our edge based real-time approach for successful and fast automatic segmentation and classification of metallic objects. Finally, experimental results on the effectiveness and performance of our approach based on a vast amount of input image data sets will be presented.
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[72] | Ingo Kofler, Hermann Hellwagner, MPEG-21-based Cross-Resource Adaptation Decision-Taking, In Proceedings of the 2nd International Conference on Automated Production of Cross Media Content for Multi-channel Distribution (AXMEDIS) (Ng Kia, Atta Badii, Pierfrancesco Bellini, eds.), Firenze University Press, Firenze, Italy, pp. 207-214, 2006.
[bib] [pdf] [abstract]
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.
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[71] | Ingo Kofler, MPEG-21-based Adaptation Decision Taking in the Binary Encoded Metadata Domain, Master's thesis, Klagenfurt University, Klagenfurt, Austria, pp. 119, 2006.
[bib] [abstract]
Abstract: The MPEG-21 standard defines a framework for the 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 delivery networks. In most cases the multimedia content can be adapted by applying different adaptation operations that result in certain properties 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 extensively 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, this generic approach enables a very generic class of optimization problems that are difficult to solve. Furthermore, the metadata is represented in XML resulting in a very verbose and ineffcient encoding. In this thesis an architecture for an Adaptation Decision Taking Engine (ADTE) is introduced. The ADTE operates both on XML metadata and on metadata encoded with the Binary Format for Metadata (BiM) enabling an effcient metadata processing. Concerning the solving of the optimization problem three different algorithms, ranging from a simple generate and test approach to the sophisticated Mesh Adaptive Direct Search, were implemented and evaluated.
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[70] | Dietmar Jannach, Klaus Leopold, Christian Timmerer, Hermann Hellwagner, A Knowledge-Based Framework For Multimedia Adaptation, In Applied Intelligence - Special Issue: Innovations in Applied Artificial Intelligence, Springer, vol. Vol. 24, no. No. 2, Berlin, Heidelberg, New York, pp. 109-125, 2006.
[bib][url] [abstract]
Abstract: Abstract Personalized delivery of multimedia content over the Internet opens new business perspectives for future multimedia applications and thus plays an important role in the ongoing MPEG-7 and MPEG-21 multimedia standardization efforts. Based on these standards, next-generation multimedia services will be able to automatically prepare the digital content before delivery according to the client’s device capabilities, the network conditions, or even the user’s content preferences. However, these services will have to deal with a variety of different end user devices, media formats, as well as with additional metadata when adapting the original media resources. In parallel, an increasing number of commercial or open-source media transformation tools will be available, capable of exploiting such descriptive metadata or dealing with new media formats; thus it is not realistic that a single tool will support all possible transformations. In this paper, we present a novel, fully knowledge-based approach for building such multimedia adaptation services, addressing the above mentioned issues of openness, extensibility, and concordance with existing and upcoming standards. In our approach, the original media is transformed in multiple adaptation steps performed by an extensible set of external tools, where the construction of adequate adaptation sequences is solved in an Artificial Intelligence planning process. The interoperability issue is addressed by exploiting standardized Semantic Web Services technology. This technology allows us to express tool capabilities and execution semantics in a declarative and well-defined form. In this context, existing multimedia standards serve as a shared domain ontology. The presented approach was implemented and successfully evaluated in an official ISO/IEC MPEG (Moving Picture Experts Group) Core Experiment and is currently under further evaluation by the standardization body.
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[69] | Teodore Guenkova-Luy, Andreas Schorr, Franz Hauck, Miguel Gómez, Christian Timmerer, Ingo Wolf, Andreas Kassler, Advanced Multimedia Management – Control Model and Content Adaptation, In Proceedings of IASTED International Conference onInternet and Multimedia Systems and Applications (EuroIMSA 2006) (Anthony Christos Boucouvalas, ed.), ACTA Press, Anaheim, CA, USA, pp. 130-135, 2006.
[bib] [pdf] [abstract]
Abstract: The delivery and adaptation of multimedia content in dis tributed and heterogeneous environments requires flexible control and management mechanisms in terminals and in control entities inside the network. In the near future, it is important to reach interoperability between the IETF ap proaches on multimedia session establishment and control and the MPEG-21 efforts for multimedia streaming and adaptation to bring advanced multimedia service provi sioning and adaptation services towards the customer. MPEG-21 Digital Item Adaptation (DIA) provides norma tive descriptions for supporting adaptation of multimedia content, but does not define interactions with transport and control mechanisms. On the other hand, the IETF standardization efforts on multimedia session control pro vide the necessary transport (e.g. RTP) and control mechanisms (SDP/SDPng). We thus bridge the gap be tween those approaches by creating a converged XML model that enables the integration of session management and negotiation protocols (e.g. SIP or Megaco) inspired by the XML formats of MPEG-21 DIA and SDPng. We also present preliminary implementation results of the con verged model along with concepts and implementation of network-based content adaptation mechanisms through media gateways that enable flexible multimedia manage ment for heterogeneous consumer terminals.
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[68] | Robbie De Sutter, Sam Lerouge, Peter De Neve, Christian Timmerer, Hermann Hellwagner, Rik Van de Walle, Comparison of XML serializations: cost benefits versus complexity, In Multimedia Systems, Springer, vol. Vol. 12, no. Nr. 2, Berlin, Heidelberg, New York, pp. 101-115, 2006.
[bib] [doi] [pdf] [abstract]
Abstract: More and more data are structured, stored, and sent over a networ using the Extensible Markup Language (XML) language. There are, however, concerns about the verbosity of XML in such a way that it may restrain further adoption of the language, especially when exchanging XML-based data over heterogeneous networks, and when it is used within constrained (mobile) devices. Therefore, alternative (binary) serialization formats of the XML data become relevant in order to reduce this overhead. However, using binary-encoded XML should not introduce interoperability issues with existing applications nor add additional complexity to new applications. On top of that, it should have a clear cost reduction over the current plain-text serialization format. A first technology is developed within the ISO/IEC Moving Picture Experts Group, namely the Binary MPEG Format for XML. It provides good compression efficiency, ability to (partially) update existingXMLtrees, and facilitates random access into, and manipulation of, the binary-encoded bit stream. Another technique is based on the Abstract Syntax Notation One specification with the Packed Encoding Rules created by the ITU-T. This paper evaluates both techniques as alternative XML serialization formats and introduces a solution for the interoperability concerns. This solution and the alternative serialization formats are validated against two real-life use cases in terms of processing speed and cost reduction. The efficiency of the alternative serialization formats are compared to a classic plain text compression technique, in particular ZIP compression.
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[67] | Robbie De Sutter, Sam Lerouge, Peter De Neve, Christian Timmerer, Hermann Hellwagner, Rik and Van de Walle, Comparison of XML serializations: cost benefit vs. complexity, In ACM Multimedia Systems, Springer, vol. Vol 12, no. No 1, London, pp. 1-15, 2006.
[bib] [abstract]
Abstract: More and more data are structured, stored, and sent over a networ using the Extensible Markup Language (XML) language. There are, however, concerns about the verbosity of XML in such a way that it may restrain further adoption of the language, especially when exchanging XML-based data over heterogeneous networks, and when it is used within constrained (mobile) devices. Therefore, alternative (binary) serialization formats of the XML data become relevant in order to reduce this overhead. However, using binary-encoded XML should not introduce interoperability issues with existing applications nor add additional complexity to new applications. On top of that, it should have a clear cost reduction over the current plain-text serialization format. A first technology is developed within the ISO/IEC Moving Picture Experts Group, namely the Binary MPEG Format for XML. It provides good compression efficiency, ability to (partially) update existingXMLtrees, and facilitates random access into, and manipulation of, the binary-encoded bit stream. Another technique is based on the Abstract Syntax Notation One specification with the Packed Encoding Rules created by the ITU-T. This paper evaluates both techniques as alternative XML serialization formats and introduces a solution for the interoperability concerns. This solution and the alternative serialization formats are validated against two real-life use cases in terms of processing speed and cost reduction. The efficiency of the alternative serialization formats are compared to a classic plain text compression technique, in particular ZIP compression.
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[66] | Anthony Vetro, Christian Timmerer, Digital Item Adaptation: Overview of Standardization and Research Activities, In IEEE Transactions on Multimedia, IEEE, vol. Special Issue on MPEG-21, Los Alamitos, CA, USA, pp. 418-426, 2005.
[bib] [doi] [pdf] [abstract]
Abstract: MPEG-21 Digital Item Adaptation (DIA) has recently been finalized as part of the MPEG-21 Multimedia Framework. DIA specifies metadata for assisting the adaptation of Digital Items according to constraints on the storage, transmission and consumption, thereby enabling various types of quality of service management. This paper provides an overview of DIA, describes its use in multimedia applications, and reports on some of the ongoing activities in MPEG on extending DIA for use in rights governed environments.
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[65] | Christian Timmerer, Hermann Hellwagner, MPEG Standards enabling Universal Multimedia Access, In Proc. of the First International Conference on Automated Production of Cross Media Content for Multi-channel Distribution (AXMEDIS 2005) (Paolo Nesi, Ng Kia, Jamie Delgado, eds.), Firenze University Press, Florence, Italy, pp. 187-196, 2005.
[bib] [abstract]
Abstract: Over the last decade, a wide spectrum of (multimedia) content has become available to an increasing number of users who desire to access it through various devices and over heterogeneous networks. Interoperability is the key for enabling transparent and augmented use of (multimedia) content across a wide range of networks and devices. Standardization efforts within the Moving Picture Experts Group (MPEG), in particular MPEG-7 and MPEG-21, aim to provide appropriate tools for achieving this goal of Universal Multimedia Access (UMA). This tutorial provides, in the first place, the concepts of UMA and corresponding MPEG-7 metadata tools built to support these concepts. Subsequently, the vision, an overview, and the state of the art of the emerging MPEG-21 Multimedia Framework are given. Finally, MPEG-21 Digital Item Adaptation (DIA) tools which implement the “Terminal and Networks Characteristics” key element within the whole framework are illustrated in detail. The goal of MPEG-21 DIA is to achieve interoperable transparent access to (distributed) advanced multimedia content by shielding users from network and terminal installation, configuration, management and implementation issues.
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[64] | Christian Timmerer, Thomas Frank, Hermann Hellwagner, Jörg Heuer, Andreas Hutter, Efficient Processing of MPEG-21 Metadata in the Binary Domain, In Proc. SPIE (Anthony Vetro, Chang Wen Chen, C-C Jay Kuo, Tong Zhang, Qi Tian, John R Smith, eds.), Spie, Boston, pp. 32-43, 2005.
[bib] [pdf] [abstract]
Abstract: XML-based metadata is widely adopted across the different communities and plenty of commercial and open source tools for processing and transforming are available on the market. However, all of these tools have one thing in common: they operate on plain text encoded metadata which may become a burden in constrained and streaming environments, i.e., when metadata needs to be processed together with multimedia content on the fly. In this paper we present an efficient approach for transforming such kind of metadata which are encoded using MPEG's Binary Format for Metadata (BiM) without additional en-/decoding overheads, i.e., within the binary domain. Therefore, we have developed an event-based push parser for BiM encoded metadata which transforms the metadata by a limited set of processing instructions – based on traditional XML transformation techniques - operating on bit patterns instead of cost-intensive string comparisons.
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[63] | Christian Timmerer, Peter Lederer, Harald Kosch, Transforming MPEG-21 generic Bitstream Syntax Descriptions within the Binary Domain, In CBMI 2005 - Fourth International Workshop on Content-Based Multimedia Indexing (Gabbouj Moncef, Astola Jaakko, Marques Ferran, eds.), CBMI, Riga, Latvia, pp. 8, 2005.
[bib] [pdf] [abstract]
Abstract: XML-based metadata is widely adopted across the different communities and plenty of commercial and open source tools for processing and transforming are available on the market. However, all of these tools have the same requirement: they operate on plain text encoded metadata which may become a burden especially in constrained and streaming environments, e.g., when metadata needs to be processed together with multimedia content which is available in a highly efficient, binary representation format. In this paper we present techniques for transforming such kind of metadata which is encoded using the well known MPEG-7 Systems Binary Format for Metadata (BiM) without additional en-/decoding overheads, i.e., within the binary domain. As such it enables us to process both the multimedia data as well as the metadata within its compressed domain, e.g., for metadata-driven adaptation purposes within intermediary network nodes which are becoming increasingly popular in the multimedia community as well as in the XML community.
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[62] | Christian Timmerer, Hermann Hellwagner, Interoperable Adaptive Multimedia Communication, In IEEE Multimedia Magazine, IEEE Computer Society, vol. 12, no. 1, Los Alamitos, USA, pp. 74-79, 2005.
[bib] [pdf] [abstract]
Abstract: Digital Item Adaptation (DIA) has been recently standardized as Part 7 of the MPEG-21 Multimedia Framework. This standard specifies tools enabling interoperable communication and adaptation of so-called Digital Items. The adaptation process becomes ever more difficult due to the heterogeneity of terminals and networks utilizing different types of multimedia contents encoded in various coding formats. Other aspects are the users� preferences and accessibility characteristics as well as the natural environment in which the content is consumed. This article describes how to use the tools within DIA in order to build a device and coding format independent adaptation module enabling interoperable multimedia communication.
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[61] | Christian Timmerer, Ingo Kofler, Johannes Liegl, Hermann Hellwagner, An Evaluation of Existing Metadata Compression and Encoding Technologies for MPEG-21 Applications, In Proceedings of the Seventh IEEE International Symposium on Multimedia (ISM) (Jeffrey Tsai, Max Mühlhäuser, Makoto Takizawa, eds.), IEEE, Washington, DC, USA, pp. 534-539, 2005.
[bib] [doi] [pdf] [abstract]
Abstract: XML-based metadata for digital media is becoming increasingly important, as a consequence also calling for efficient encoding and compression schemes for the storage and transport of this metadata. Moreover, support for streaming the XML metadata in conjunction with the media data is highly desirable. Such support is provided, for instance, by MPEG's Binary Format for Metadata (BiM) encoding approach, which facilitates fragmenting, delivering, and accessing the metadata in so- called Access Units (AUs). In this paper, we present a quantitative evaluation of existing XML metadata compression and encoding techniques, reaching from widely used state-of-the-art data compression algorithms to sophisticated XML-aware encoding schemes. The comparison is based on compressing MPEG-21 generic Bitstream Syntax Descriptions (gBSDs) which can grow to non-negligible sizes. The main conclusion from this investigation is that in terms of pure compression efficiency on XML files, the BiM approach (exemplified by the MPEG reference software as well as a commercial version thereof) is comparable – in terms of performance – with traditional data or specific XML compression tools. However, when XML metadata have to be fragmented, compressed, and streamed in such fragments, the results indicate that the BiM approach is superior to the other schemes.
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[60] | Christian Timmerer, Gabriel Panis, Eric Delfosse, Piece-wise Multimedia Content Adaptation in Streaming and Constrained Environments, In Proceedings of the 6th International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS 2005) (Frederic Dufaux, Touradj Ebrahimi, Michael Strintzis, eds.), WIAMIS, Montreux, pp. 4, 2005.
[bib] [pdf] [abstract]
Abstract: Universal Multimedia Access (UMA) has become a driving concept behind a significant amount of research activities. One of MPEG’s (Moving Pictures Experts Group) responses to UMA is MPEG-21 Digital Item Adaptation (DIA). In this paper we present how tools as specified within DIA (i.e., normative XML-based description formats) are applied in streaming and constrained environments enabling piece-wise multimedia content adaptation including the adaptation decision- taking process and the actual resource adaptation in a coding format-independent way. Additionally, we demonstrate how the metadata overhead imposed by DIA tools can be reduced by means of appropriate metadata encoding tools.
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[59] | Peter Schojer, Laszlo Böszörmenyi, Hermann Hellwagner, An Adaptive Standard Meta-data Aware Proxy Cache, In Scalable Computing: Practice and Experience, SCPE, vol. Vol 6, no. No 2, Timisoara, Romania, pp. 93-104, 2005.
[bib] [abstract]
Abstract: Multimedia is gaining ever more importance on the Internet. This increases the need for intelligent and efficient video caches. A promising approach to improve caching efficiency is to adapt videos. With the availability of MPEG-4 it is possible to develop a standard compliant proxy cache that allows fast and efficient adaptation. We propose a modular design for an adaptive MPEG-4 video proxy that supports efficient full and partial video caching in combination with filtering options that are driven by the terminal capabilities of the client. We use the native scalability operations provided by MPEG-4, the MPEG-7 standard to describe the scalability options for a video and the emerging MPEG-21 standard to describe the terminal capabilities. We restrict ourselves to full video caching. The combination of adaptation with MPEG-4, MPEG-7 and client terminal capabilities is to the best of our knowledge unique and will increase the quality of service for end users. Key words: Adaptation, MPEG-4, MPEG-7, MPEG-21, adaptive proxy, caching.
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[58] | Michael Ransburg, Christian Timmerer, Hermann Hellwagner, Transport mechanisms for metadata-driven distributed multimedia adaptation, In Proceedings of the First International Conference on Multimedia Services Access Networks (MSAN 2005) (A N, ed.), IEEE CS Press, Orlando, USA, pp. 25-29, 2005.
[bib] [doi] [pdf] [abstract]
Abstract: The information revolution of the last decade has resulted in a phenomenal increase in the quantity of multimedia content available to an increasing number of different users with different preferences who access it through a plethora of devices and over heterogeneous networks. In order to address the amount of different content types, MPEG-21 Digital Item Adaptation (DIA) introduces interoperable description tools which enable coding format independent adaptation. Bandwidthefficient transport of the content to terminals with different capabilities and through a variety of access networks with various characteristics requires adaptation facilities not only on the server but also within the network. In this paper we present transport mechanisms for MPEG-21-based metadata enabling generic adaptation within the network. Three different transport mechanisms for delivering this metadata in conjunction with the corresponding multimedia content are evaluated and a payload format for the transport of this metadata is presented. Furthermore, we performed measurements which demonstrate the bandwidth benefits of our distributed adaptation approach compared to server-centric adaptation in a multicast scenario. Finally, we applied various encoding formats for the metadata which further reduces the metadata overhead.
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[57] | Michael Ransburg, Hermann Hellwagner, Generic Streaming of Multimedia Content, In Proceedings of IASTED International Conference on Internet and Multimedia Systems and Applications (EuroIMSA 2005) (Mohamed H Hamza, ed.), ACTA Press, Grindelwald, pp. 324-330, 2005.
[bib] [abstract]
Abstract: The growing demand for multimedia information by different types of users equipped with a large variety of devices and connecting through different kinds of networks results in an increasing amount of different multimedia formats. Research is currently concentrating on the adaptation of the contents in order to provide Universal Multimedia Access (UMA) for the content consumer. But this does not solve the problem of the content provider, who still has to signal this variety of different multimedia formats to the consumer. In this contribution, we show a way to stream any type of multimedia format based on generic hint information. This hint information is based on a generic bit stream syntax description (gBSD) which is used for format-independent content adaptation within the MPEG-21 Multimedia Framework. Ultimately, this can lead to a frame-work which allows generic streaming and generic adaptation anywhere in the network.
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