[23] | Evsen Yanmaz, Robert Kuschnig, Christian Bettstetter, Channel Measurements Over 802.11a-Based UAV-to-Ground Links, In Proceedings of the GlobeCom 2010 (Wi-UAV Workshop) (Jonathan How, Christian Wietfeld, eds.), IEEE, Piscataway, NJ, USA, pp. 5, 2011.
[bib] [pdf] [abstract]
Abstract: The distribution of audio-visual content over the Internet has become very popular in recent years. However, due to the bandwidth requirements of videos in high definition, a costefficient distribution is desirable. In this paper we present a low-cost consumer electronics set-top box for streaming live video content using cost-efficient P2P networks. The main features of the set-top box include content discovery, highquality playback, easy user management, and social interaction.
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[22] | Evsen Yanmaz, Robert Kuschnig, Markus Quaritsch, Christian Bettstetter, Bernhard Rinner, On Path Planning Strategies for Networked Unmanned Aerial Vehicles, In Proceedings of the IEEE Conference on Computer Communications Workshops, INFOCOM M2MCN, 2011 (Lionel Ni, Wenjun Zhang, eds.), IEEE, Piscataway, NJ, USA, pp. 212-216, 2011.
[bib] [pdf] [abstract]
Abstract: The distribution of audio-visual content over the Internet has become very popular in recent years. However, due to the bandwidth requirements of videos in high definition, a costefficient distribution is desirable. In this paper we present a low-cost consumer electronics set-top box for streaming live video content using cost-efficient P2P networks. The main features of the set-top box include content discovery, highquality playback, easy user management, and social interaction.
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[21] | Markus Waltl, The Next Dimension of Video Experience: Sensory Effects, In Proceedings of the 12th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM) (Mario Gerla, Enzo Mingozzi, Mainak Chatterjee, Andrea Passarella, eds.), IEEE, Los Alamitos, CA, USA, pp. 3, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: This work presents a new dimension for Quality of Experience (QoE), i.e., sensory information. Sensory information enhances the user experience by providing additional so-called sensory effects (e.g., wind, light, vibration) which are rendered together with multimedia content. Furthermore, the work describes two subjective quality assessments conducted in this area including their results.
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[20] | Markus Waltl, Christian Timmerer, Benjamin Rainer, Hermann Hellwagner, Sensory Effects for Ambient Experiences in the World Wide Web, Alpen-Adria Universität Klagenfurt, no. TR/ITEC/11/1.13, Klagenfurt, Austria, pp. 12, 2011.
[bib] [pdf] [abstract]
Abstract: More and more content in various formats become available via the World Wide Web (WWW). Currently available Web browsers are able to access and interpret these contents (i.e., Web videos, text, image, and audio). These contents stimulate only senses like audition or vision. Recently, it has been proposed to stimulate also other senses while consuming multimedia content through so-called sensory effects. These sensory effects aim to enhance the ambient experience by providing effects, such as, light, wind, vibration, etc. The effects are represented as Sensory Effect Metadata (SEM) which is associated to multimedia content and is rendered on devices like fans, vibration chairs, or lamps. In this paper we present a plug-in for the Mozilla Firefox browser which is able to render such sensory effects that are provided via the WWW. Furthermore, the paper describes two user studies conducted with the plug-in and presents the results achieved.
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[19] | Markus Waltl, Benjamin Rainer, Christian Timmerer, Hermann Hellwagner, Sensory Experience for Videos on the Web, In Proceedings of the Workshop on Multimedia on the Web (MMWeb) 2011 (Laszlo Böszörmenyi, Oge Marques, Mathias Lux, Ralf Klamma, eds.), IEEE, Los Alamitos, CA, USA, pp. 1-3, 2011.
[bib] [pdf] [abstract]
Abstract: More and more multimedia content is becoming available via the World Wide Web (WWW). These contents stimulate only senses like hearing or vision. Recently, it has been proposed to stimulate also other senses while consuming multimedia content, through so-called sensory effects. These sensory effects aim at enhancing the user’s viewing experience by providing effects such as light, wind, vibration, etc. These effects are represented as Sensory Effect Metadata (SEM) which is associated to multimedia content and is rendered on devices like fans, lamps, or vibration chairs. In this paper, we present a plug-in for Web browsers which is able to render such sensory effects provided via Web content, and we describe a demonstrator that uses this plug-in to control an amBX system.
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[18] | Daniel Gatica-Perez, Thomas Gottron, Martin Hahn, Jim Hurley, Yiannis Kompatsiaris, Marta Larson, Barnabas Takacs, Christian Timmerer, David Wortley, Vision 2020 on Networked Media and Web Applications, Technical report, European Commission, Brussels, Belgium, pp. 110, 2011. (Internal communication of the European Commission. Brussels 2011, Available at the Author.)
[bib] |
[17] | Tibor Szkaliczki, Michael Eberhard, Hermann Hellwagner, Laszlo Szobonya, Knapsack Problem and Piece Picking Algorithms for Layered Video Streaming, In 7th Japanese-Hungarian Symposium on Discrete Mathematics and its Applications (Takuro Fukunaga, Satoru Iwata, Hiroshi Nagamochi, Kenjiro Takazawa, eds.), published on workshop homepage, Kyoto, Japan, pp. 419-426, 2011.
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[16] | Mark Stuart, Mike Buckham, Richard Marsh, Michael Eberhard, Johnathan Ishmael, Chris Needham, Christian Timmerer, NextShareTV: A Set-Top Box for Bittorrent-based Live Streaming, In Proceedings of the 2011 IEEE International Conference on Multimedia and Expo (ICME 2011) (Irene Cheng, Gabriel Fernandez, Haohong Wang, eds.), IEEE, Los Alamitos, CA, USA, pp. 1, 2011.
[bib] [pdf] [abstract]
Abstract: The distribution of audio-visual content over the Internet has become very popular in recent years. However, due to the bandwidth requirements of videos in high definition, a costefficient distribution is desirable. In this paper we present a low-cost consumer electronics set-top box for streaming live video content using cost-efficient P2P networks. The main features of the set-top box include content discovery, highquality playback, easy user management, and social interaction.
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[15] | Markus Quaritsch, Robert Kuschnig, Hermann Hellwagner, Bernhard Rinner, Fast Aerial Image Acquisition and Mosaicking for Emergency Response Operations by Collaborative UAVs, In Proceedings of the 8th International Conference on Information Systems for Crisis Response and Management (ISCRAM 2011) (Julie Dugdale, David Mendonça, eds.), Springer, Berlin, Heidelberg, New York, pp. 5, 2011.
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[14] | Markus Quaritsch, Robert Kuschnig, Daniel Wischounig-Strucl, Saeed Yahyanejad, Vera Mersheeva, Evsen Yanmaz, Gerhard Friedrich, Hermann Hellwagner, Christian Bettstetter, Bernhard Rinner, FAMUOS: A Multi-UAV System for Aerial Reconnaissance in Rescue Scenarios, In Proceedings of the Austrian Robotics Workshop (ARW-11) (Michael Hofbaur, Manfred Husty, eds.), UMIT, Hall in Tyrol, Austria, pp. 3 3 3, 2011.
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[13] | Christopher Mueller, Christian Timmerer, A VLC media player plugin enabling dynamic adaptive streaming over HTTP, In Proceedings of the 19th ACM international conference on Multimedia (Kasim Selcuk Candan, Sethuraman Panchanathan, Balakrishnan Prabhakaran, Hari Sundaram, Wu-Chi Feng, Nicu Sebe, eds.), ACM, New York, NY, USA, pp. 723-726, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: This paper describes the implementation of a VLC media player plugin enabling Dynamic Adaptive Streaming over HTTP (DASH). DASH is an emerging ISO/IEC MPEG and 3GPP standard for HTTP streaming. It aims to standardize formats enabling segmented progressive download by exploiting existing Internet infrastructure as such. Our implementation of these formats as described in this paper is based on the well-known VLC. Hence, it is fully integrated into the VLC structure and has been also submitted to the VLC development team for consideration in future releases of VLC. Therefore, it is licensed under the GNU Lesser General Public License (LGPL). The plugin provides a very flexible structure that could be easily extended with respect to different adaptation logics or profiles of the DASH standard. As a consequence, the plugin enables the integration of a variety of adaptation logics and comparison thereof, making it attractive for the research community.
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[12] | Christopher Mueller, Christian Timmerer, A Test-Bed for the Dynamic Adaptive Streaming over HTTP featuring Session Mobility, In Proceedings of the Second Annual ACM SIGMM Conference on Multimedia Systems (MMSys) (Ketan Mayer-Patel, Ali Begen, eds.), ACM, New York, NY, USA, pp. 271-276, 2011.
[bib] [pdf] [abstract]
Abstract: In this paper, we present a multimedia test-bed enabling session mobility in the context of the emerging ISO/IEC MPEG standard, Dynamic Adaptive Streaming over HTTP (DASH). In general, session mobility is defined as the transfer of a running streaming session from one device to another device where it may need to be consumed in an adaptive way. The two main challenges are: (1) taking into account the new context of the device (e.g., capabilities) to which the session is transferred and (2) performing the actual transfer in a seamless and interoperable way. Our system addresses both challenges supported by a prototype implementation integrated into VLC. In anticipation of the results we can conclude that interoperability is achieved adopting existing standards while the performance of the system does not depend on these standards. That is, the modules responsible for the performance are usually not defined within such standards and left out for competition. However, our system is designed in an extensible way and is able to accommodate this fact.
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[11] | Robert Kuschnig, Ingo Kofler, Hermann Hellwagner, Evaluation of HTTP-based request-response streams for internet video streaming, In Proceedings of the Second Annual ACM SIGMM Conference on Multimedia Systems (MMSys) (Ketan Mayer-Patel, Ali Begen, eds.), ACM, New York, NY, USA, pp. 245-256, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: Adaptive video streaming based on TCP/HTTP is becoming popular because of its ability to adapt to changing network conditions. We present an in-depth experimental analysis of the use of HTTP-based request-response streams for video streaming. In this scheme, video fragments are fetched by a client from the server, in smaller units called chunks, potentially via multiple parallel HTT P requests (TCP connections). A model for the achievable throughput is formulated.The model is validated by a broad range of streaming experiments, including an evaluation of TCP-friendliness. Our findings include that request-response streams are able to scale with the available bandwidth by increasing the chunk size or the number of concurrent streams. Several combinations of system parameters exhibiting TCP-friendliness are presented. We also evaluate the video streaming performance in terms of video quality in the presence of packet loss. Multiple request-response streams are able to maintain satisfactory performance, while a single TCP connection deteriorates rapidly with increasing packet loss. The results provide experimental evidence that HTTP-based request-response streams are a good alternative to classical TCP streaming
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[10] | Harilaos Koumaras, Daniel Negru, Eugen Borcoci, Vaios Koumaras, Costas Troulos, Yael Lapid, Evangelos Pallis, Mamadou Sidibé, Antonia Pinto, Georgios Gardikis, George Xilouris, Christian Timmerer, Media Ecosystems: A Novel Approach for Content-Awareness in Future Networks, Chapter in The Future Internet (John Domingue, Alex Galis, Anastasius Gavras, Theodore Zahariadis, Dave Lambert, Frances Cleary, Petros Daras, Srdjan Krco, Henning Müller, Man-Sze Li, Hans Schaffers, Volkmar Lotz, Federico Alvarez, Burkhard Stiller, Stamatis Karnouskos, Susanna Avessta, Michael Nilsson, eds.), Springer, vol. 6656, Berlin, Heidelberg, New York, pp. 369-380, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: This chapter proposes a novel concept towards the deployment of a networked ‘Media Ecosystem’. The proposed solution is based on a flexible co- operation between providers, operators, and end-users, finally enabling every user first to access the offered multimedia services in various contexts, and second to share and deliver his own audiovisual content dynamically, seamlessly, and transparently to other users. Towards this goal, the proposed concept provides content-awareness to the network environment, network- and user context- awareness to the service environment, and adapted services/content to the end user for his best service experience possible, taking the role of a consumer and/or producer.
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[9] | Ingo Kofler, Robert Kuschnig, Hermann Hellwagner, Evaluating the Networking Performance of Home Router Platforms for Multimedia Services, In Proceedings of the 2011 IEEE International Conference on Multimedia and Expo (ICME 2011) (Irene Cheng, Gabriel Fernandez, Haohong Wang, eds.), IEEE, Los Alamitos, CA, USA, pp. 6, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: Wireless router platforms based on the Linux operating system are becoming popular in consumers' home networks. The transmission of multimedia data or their use as media-aware network elements imposes high traffic and computational loads on these devices. Thus, it is interesting to evaluate the networking and processing capabilities of such home router platforms in order to assess their usefulness for improved multimedia services such as in-network H.264/SVC video stream adaptation. This paper presents a performance evaluation of three home router platforms representative for low-end, mid-range, and high-end devices. The scope of the evaluation is the performance of the Linux networking stack on these routers; results for both application-layer (TCP and UDP) transmission and kernel-level (UDP) traffic routing are given. The results show that both TCP and UDP throughputs are significantly below (less than half of) the outgoing (wired) links' nominal capacities and depend very much on the sizes of the transmitted data blocks. This clearly indicates that the networking performance is limited by the platforms' processing capabilities and the lack of mechanisms that offload networking tasks from the CPUs. This behaviour cannot be observed on today's PC systems and has to be considered when deploying multimedia services on these network devices. Furthermore, a detailed analysis of the Linux networking stack reveals that the performance is heavily impacted by the netfilter code, even when no packet filtering or network address translation is being performed. Considerable performance gains can be achieved when this netfilter code is bypassed.
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[8] | Ingo Kofler, Robert Kuschnig, Hermann Hellwagner, In-Network Adaptation of H.264/SVC for HD Video Streaming Over 802.11g Networks, In Proceedings of the 21st International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV 2011) (Charles Krasic, Kang Li, eds.), ACM, New York, NY, USA, pp. 9-14, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: In this paper, we present an approach for in-network adaptation of H.264/SVC in the context of 802.11 wireless networks. It builds upon our previous work on an adaptive RTSP/RTP proxy which allows to adapt video streams on Linux-based home router platforms. The proposed approach tackles the throughput variations that occur as a consequence of the physical rate adaptation in 802.11 equipment caused by the mobility of clients. By combining monitoring information available exclusively on the wireless router with the ability to adapt scalable video streams on-the-fly, the proposed in-network adaptation approach allows to quickly adjust the video bit rate to the current link conditions. Instead of reacting on packet loss, our approach uses an increase in queueing delay at the router to detect phases of throughput degradation. This allows a higher responsiveness compared to traditional end-to-end approaches that rely solely on RTCP feedback. The behavior of our novel approach was evaluated in several mobility scenarios in an experimental test bed. The results obtained by streaming and adapting high-definition content clearly demonstrate the feasibility and benefits of this approach.
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[7] | Hermann Hellwagner, Heinz Hofbauer, Robert Kuschnig, Thomas Stütz, Andreas Uhl, Secure transport and adaptation of MC-EZBC video utilizing H.264-based transport protocols, In Journal on Signal Processing: Image Communication, Elsevier B.V., Amsterdam, Netherlands, pp. 30, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: Universal Multimedia Access (UMA) calls for solutions where content is created once and subsequently adapted to given requirements. With regard to UMA and scalability, which is required often due to a wide variety of end clients, the best suited codecs are wavelet based (like the MC-EZBC) due to their inherent high number of scaling options. However, most transport technologies for delivering videos to end clients are targeted toward the H.264/AVC standard or, if scalability is required, the H.264/SVC. In this paper we will introduce a mapping of the MC-EZBC bitstream to existing H.264/SVC based streaming and scaling protocols. This enables the use of highly scalable wavelet based codecs on the one hand and the utilization of already existing network technologies without accruing high implementation costs on the other hand. Furthermore, we will evaluate different scaling options in order to choose the best option for given requirements. Additionally, we will evaluate different encryption options based on transport and bitstream encryption for use cases where digital rights management is required.
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[6] | Hermann Hellwagner, Ingo Kofler, Michael Eberhard, Robert Kuschnig, Michael Ransburg, Michael Sablatschan, Scalable Video Coding: Techniques and Applications for Adaptive Streaming, Chapter in Streaming Media Architectures, Techniques and Applications: Recent Advances (Ce Zhu, Yuenan Li, Xiamu Niu, eds.), Information Science Reference, Hershey, PA, USA, pp. 1-23, 2011.
[bib] [doi] [abstract]
Abstract: This chapter covers the topic of making use of scalable video content in streaming frameworks and applications. Specifically, the recent standard H.264/SVC, i.e., the scalable extension of the widely used H.264/AVC coding scheme, and its deployment for adaptive streaming, the combined activities of content adaptation and streaming, are considered. H.264/SVC is regarded as a promising candidate to enable applications to cope with bandwidth variations in networks and heterogeneous usage environments, mainly diverse end device capabilities and constraints. The relevant coding and transport principles of H.264/SVC are reviewed first. Subsequently, an overview of H.264/SVC applications is given. The chapter then focuses on presenting architectural/implementation options and applications of H.264/SVC for adaptive streaming, emphasizing the aspect of where, i.e., on which network node and on which layer in the networking stack, in the video delivery path the content adaptation can take place; also, methods of content adaptation are covered. This pragmatic perspective is seen as complementing more general discussions of scalable video adaptation issues in the existing literature.
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[5] | Michael Grafl, SVC Tunneling for Media-Aware Content Delivery: Impact on Video Quality, In Proceedings of the 12th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM) (Mario Gerla, Enzo Mingozzi, Mainak Chatterjee, Andrea Passarella, eds.), IEEE, Los Alamitos, CA, USA, pp. 3, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: Today's omnipresent demand for access to multimedia content via diverse devices places new challenges on efficient content delivery. This work introduces the concept of Scalable Video Coding (SVC) tunneling developed in the EU FP7 ALICANTE project and shows that the quality impact of the transcoding steps for a transcoding chain from MPEG-2 to SVC and back to MPEG-2 accumulates to a PSNR reduction of up to 2.1 dB for transcoding at fixed target bitrate points. We also discuss research challenges and open issues in SVC tunneling.
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[4] | Michael Grafl, Christian Timmerer, Hermann Hellwagner, Quality Impact of Scalable Video Coding Tunneling for Media-Aware Content Delivery, In Proceedings of the 2011 IEEE International Conference on Multimedia and Expo (ICME 2011) (Irene Cheng, Gabriel Fernandez, Haohong Wang, eds.), IEEE, Los Alamitos, CA, USA, pp. 4, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: Today's omnipresent demand for access to multimedia content via diverse devices places new challenges on efficient content delivery. While the Scalable Video Coding (SVC) extension of Advanced Video Coding (AVC) has proven to be a useful tool for the advanced delivery of video content, it has not yet found major adoption in practice. This paper introduces the concept of SVC tunneling developed in the EU FP7 ALICANTE project, which attempts to provide device-independent access to media resources at reduced network load. For SVC tunneling, video transcoding is performed at the ingress/egress points of the network, which may impact the video quality. We show that the quality impact of these transcoding steps for a transcoding chain from MPEG-2 to SVC and back to MPEG-2 accumulates to a PSNR reduction of up to 2.1 dB for transcoding at fixed target bitrates. We also discuss research challenges and open issues in SVC tunneling.
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[3] | Michael Grafl, Christian Timmerer, Hermann Hellwagner, Daniel Negru, Eugen Borcoci, Daniele Renzi, Anne-Lore Mevel, Alex Chernilov, Scalable Video Coding in Content-Aware Networks: Research Challenges and Open Issues, Chapter in Trustworthy Internet (Nicola Blefari-Melazzi, Giuseppe Bianchi, Luca Salgarelli, eds.), Springer, Berlin, Heidelberg, New York, pp. 11, 2011.
[bib] [doi] [pdf] [abstract]
Abstract: The term “trustworthy” has a very precise connotation in the European Community’s FP7 research program. For a network to be qualified as trustworthy, it needs to be secure, reliable and resilient to attacks and operational failures. Furthermore, quality of service must be guaranteed, while protecting user data, ensuring privacy and providing usable and trusted tools to support users in their security management. As such, the Trustworthy Internet not only has to include mechanisms, architectures and networking infrastructures that intrinsically provide basic security guarantees, but it also has to ensure users, service providers and application providers alike that their requirements in terms of Quality of Experience, manageability and efficiency are fully met. Providing such combined guarantees in a rapidly evolving, complex infrastructure such as the Internet requires solving challenging issues that encompass many fields of theoretical and applied information engineering. These issues span all levels of the protocol stack, ranging from finding new intrinsically secure transmission systems, to radically novel routing models, to new architectures for data dissemination and for interconnecting an unprecedented number of devices and appliances. This book aims at representing a view of the state of the “Trustworthy Internet” as we enter the second decade of our century. The material included in this book originated from the 21st International Tyrrhenian Workshop on Digital Communications, an event traditionally organized by CNIT, the Italian inter-university consortium for telecommunication research. The workshop comprised either invited contributions from renowned researchers with complementary expertise, as well as independent, peer-reviewed contributions stimulated through an open call for papers. This volume includes a selected subset of the workshop papers. Each contribution has been edited and extended after the workshop, taking into account the discussions carried out during the event, incorporating when appropriate additional technical material. Furthermore, the authors have strived to complement the specific technical aspects they present with background material devised to more comprehensively introduce the reader to the specific topic of trustworthiness tackled.
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[2] | Michael Eberhard, Hermann Hellwagner, Christian Timmerer, Tibor Szkaliczki, Laszlo Szobonya, An evaluation of piece-picking algorithms for layered content in Bittorrent-based peer-to-peer systems, In Proceedings of the 2011 IEEE International Conference on Multimedia and Expo (ICME 2011) (Irene Cheng, Gabriel Fernandez, Haohong Wang, eds.), IEEE, Los Alamitos, CA, USA, pp. 1-6, 2011.
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[1] | Michael Eberhard, Amit Kumar, Silvano Mignanti, Riccardo Petrocco, Mikko Uitto, A Framework for Distributing Scalable Content over Peer-to-Peer Networks, In International Journal on Advances in Internet Technology, IARIA, vol. 4, no. 1&2, N/A, pp. 1-13, 2011.
[bib] [pdf] [abstract]
Abstract: Peer-to-Peer systems are nowadays a very popular solution for multimedia distribution, as they provide significant cost benefits compared with traditional server-client distribution. Additionally, the distribution of scalable content enables the consumption of the content in a quality suited for the available bandwidth and the capabilities of the end-user devices. Thus, the distribution of scalable content over Peer-to-Peer network is a very actual research topic. This paper presents a framework for the distribution of scalable content in a fully distributed Peer-to-Peer network. The architectural description includes how the scalable layers of the content are mapped to the pieces distributed in the Peer-to-Peer system and detailed descriptions of the producer- and consumer-site architecture of the system. Additionally, an evaluation of the system’s performance in different scenarios is provided. The test series in the evaluation section assess the performance of our layered piece-picking core and provide a comparison of the performance of our system’s multi layer and single layer implementations. The presented system is to our knowledge the first open-source Peer-to-Peer network with full Scalable Video Coding support.
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