[129] | 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.
|
[128] | 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.
|
[127] | 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.
|
[126] | 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.
|
[125] | 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.
[bib] [pdf] |
[124] | 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.
|
[123] | 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.
[bib] [pdf] |
[122] | 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.
[bib] [pdf] |
[121] | 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.
|
[120] | 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.
|
[119] | 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
|
[118] | 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.
|
[117] | 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.
|
[116] | 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.
|
[115] | 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.
|
[114] | 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.
[bib] [pdf] |
[113] | Markus Waltl, Christian Timmerer, Hermann Hellwagner, Increasing the User Experience of Multimedia Presentations with Sensory Effects, In Proceedings of the 11th International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS'10) (Riccardo Leonardi, Pierangelo Migliorati, Andrea Cavallaro, eds.), IEEE, Los Alamitos, CA, USA, pp. 1-4, 2010.
[bib] [pdf] [abstract]
Abstract: The term Universal Multimedia Experience (UME) has gained momentum and is well recognized within the research community. As this approach puts the user into the center stage, additional complexity is added to the overall quality assessment problem which calls for a scientific framework to capture, measure, quantify, judge, and explain the user experience. In previous work we have proposed the annotation of multimedia content with sensory effect metadata that can be used to stimulate also other senses than vision or audition. In this paper we report first results obtained from subjective tests in the area of sensory effects attached to traditional multimedia presentations such as movies that shall lead to an enhanced, unique, and worthwhile user experience.
|
[112] | Markus Waltl, Christian Timmerer, Hermann Hellwagner, Improving the Quality of Multimedia Experience through Sensory Effects, In Proceedings of the 2nd International Workshop on Quality of Multimedia Experience (QoMEX'10) (Andrew Perkis, Sebastian Möller, Peter Svensson, Amy Reibman, eds.), IEEE, Los Alamitos, CA, USA, pp. 124-129, 2010.
[bib][url] [doi] [pdf] [abstract]
Abstract: In previous and related work sensory effects are presented as a tool for increasing the user experience of multimedia presentations by stimulating also other senses than vision or audition. In this paper we primarily investigated the relationship of the Quality of Experience (QoE) due to various video bit-rates of multimedia contents annotated with sensory effects (e.g., wind, vibration, light). Therefore, we defined a subjective quality assessment methodology based on standardized methods. The paper describes the test environment, its setup, and conditions in detail. Furthermore, we experimented with a novel voting device that allows for continuous voting feedback during a sequence in addition to the overall quality voting at the end of each sequence. The results obtained from the subjective quality assessment are presented and discussed thoroughly. In anticipation of the results we can report an improvement of the quality of the multimedia experience thanks to the sensory effects.
|
[111] | Markus Waltl, Christian Raffelsberger, Christian Timmerer, Hermann Hellwagner, Metadata-based Content Management and Sharing System for Improved User Experience, In Proceedings CD of the 2nd International ICST Conference on User Centric Future Media Internet (Federico Alvarez, Cristina Costa, eds.), Springer Verlag GmbH, Berlin, Heidelberg, New York, pp. 1-9, 2010.
[bib] [pdf] [abstract]
Abstract: In the past years the amount of multimedia content on the Internet or in home networks has been drastically increasing. Instead of buying traditional media (such as CDs or DVDs) users tend to buy online media. This leads to the difficulty of managing the content (e.g., movies, images). A vast amount of tools for content management exists but they are mainly focusing on one type of content (e.g., only images). Furthermore, most of the available tools are not configurable to the user’s preferences and cannot be accessed by different devices (e.g., TV, computer, mobile phone) in the home network. In this paper we present a UPnP A/V-based system for managing and sharing audio/visual content in home environments which is configurable to the user’s preferences. Furthermore, the paper depicts how this system can be used to improve the user experience by using MPEG-V.
|
[110] | Christian Timmerer, Markus Waltl, Hermann Hellwagner, Are Sensory Effects Ready for the World Wide Web?, In Proceedings of the Workshop on Interoperable Social Multimedia Applications (WISMA 2010) (Anna Carreras, Jaime Delgado, Xavier Maroñas, Víctor Rodríguez, eds.), CEUR Workshop Proceedings (CEUR-WS.org), Aachen, Germany, pp. 57-60, 2010.
[bib] [pdf] [abstract]
Abstract: The World Wide Web (WWW) is one of the main entry points to access and consume Internet content in various forms. In particular, the Web browser is used to access different types of media (i.e., text, image, audio, and video) and on some platforms is the only way to access the vast amount of information on the Web. Recently, it has been proposed to stimulate also other senses than vision or audition while consuming multimedia content through so- called sensory effects, with the aim to increase the user’s Quality of Experience (QoE). The effects are represented as Sensory Effects Metadata (SEM) which is associated to traditional multimedia content and is rendered (synchronized with the media) on sensory devices like fans, vibration chairs, lamps, etc. In this paper we provide a principal investigation of whether the sensory effects are ready for the WWW and, in anticipation of the result, we propose how to embed sensory effect metadata within Web content and the synchronized rendering thereof.
|
[109] | Christian Timmerer, Michael Eberhard, Michael Grafl, Keith Mitchell, Sam Dutton, Hermann Hellwagner, A Metadata Model for Peer-to-Peer Media Distribution, In Proceedings of the Workshop on Interoperable Social Multimedia Applications (WISMA 2010) (Anna Carreras, Jaime Delgado, Xavier Maroñas, Víctor Rodríguez, eds.), CEUR Workshop Proceedings (CEUR-WS.org), Aachen, Germany, pp. 8, 2010.
[bib][url] [pdf] [abstract]
Abstract: In this paper we describe a metadata solution for a Peer-to-Peer (P2P) content distribution system termed NextShare. We outline the key motivating factors for our approach, detail the overall generic architecture we have developed and present the workflow for delivering metadata through Peer-to-Peer based content distribution. The paper also presents the metadata model we have developed and we describe in detail how all the content can be packetized and distributed using NextShare. Finally, a description of the core and optional metadata attributes which may be utilized within the system is provided.
|
[108] | Christian Timmerer, Christopher Mueller, HTTP Streaming of MPEG Media, In Proceedings of STreaming Day 2010 (Riccardo Bernardini, Fabrizio Rovati, eds.), Rovati, Fabrizio, Agrate B.za, Italy, pp. 4, 2010.
[bib] [pdf] [abstract]
Abstract: MPEG has developed various technologies for multimedia transport, such as MPEG-2 Transport Stream (TS) and ISO Media Base File Format. These technologies have been widely accepted and heavily used by various industries and applications, such as digital broadcasting, audio and video transport over the Internet, mobile phones, etc. In recent years, the Internet has become an important channel for the delivery of multimedia. As HTTP is widely used on the Internet, it has recently been used extensively for the delivery of multimedia content. However, there is no standard for HTTP- based streaming of MPEG media. MPEG intends to standardize a solution that addresses this need. This paper provides an overview of the recent Call of Proposals (CfP) for HTTP Streaming of MPEG Media, a new work item within ISO/IEC MPEG. In particular, it will provide an overview of existing systems and the outcome of the evaluation of the aforementioned CfP which has been conducted during the 93rd MPEG meeting in July 2010.
|
[107] | Christian Timmerer, Michael Grafl, Hermann Hellwagner, Daniel Negru, Eugen Borcoci, Daniel Renzi, Anne-Lore Mevel, Alex Chernilov, Scalable Video Coding in Content-Aware Networks: Research Challenges and Open Issues, In Proceedings of the International Tyrrhenian Workshop on Digital Communications (ITWDC) (Nicola Blefari-Melazzi, ed.), Springer, New York, NY, USA, pp. 11, 2010.
[bib] [pdf] [abstract]
Abstract: The demand for access to advanced, distributed media resources is nowadays omnipresent due to the availability of Internet connectivity almost anywhere, anytime, and with a huge amount of different devices. This calls for rethinking of the current Internet architecture by making the network aware of which content is actually transported. This paper introduces Scalable Video Coding (SVC) as a tool for Content-Aware Networks (CANs) which is currently researched as part of the EU FP7 ALICANTE project. The architecture of ALICANTE with respect to SVC and CAN is reviewed, use cases are described, and, finally, research challenges and open issues are discussed.
|
[106] | Christian Timmerer, Hermann Hellwagner, MPEG-21 digital items in research and practice, In Proceedings of the 1st International Digital Preservation Interoperability Framework Symposium (Wo Chang, ed.), ACM, New York, NY, USA, pp. 8:1-8:8, 2010.
[bib] [doi] [pdf] [slides] [abstract]
Abstract: The aim of the MPEG‐21 standard, the so‐called Multimedia Framework, is to enable transparent and augmented use of multimedia resources across a wide range of networks, devices, user preferences, and communities, notably for trading (of bits). As such, it provides an important step in MPEG's standards evolution, i.e., the transaction of Digital Items among Users. This paper provides an overview of applications making use specifically of MPEG‐21 Digital Items and a more in‐depth presentation of a few selected applications in research and practice.
|
[105] | Christian Timmerer, Karsten Müller, Immersive Future Media Technologies: From 3D Video to Sensory Experiences, In Proceedings of the International Conference on Multimedia (MM '10) (Alberto del Bimbo, Shih-Fu Chang, Arnold Smeulders, eds.), ACM, New York, NY, USA, pp. 1781-1782, 2010.
[bib][url] [doi] [pdf] [abstract]
Abstract: In this tutorial we present immersive future media technologies ranging from 3D video to sensory experiences. The former targets stereo and multi-view video technologies whereas the latter aims at stimulating other senses than vision or audition enabling an advanced user experiences through sensory effects.
|