[37] | Barry Crabtree, Tim Stevens, Brahin Allan, Stefan Lederer, Daniel Posch, Christopher Mueller, Christian Timmerer, Video Adaptation in Limited or Zero Network Coverage, In CCNxConn 2013 (Priya Mahadevan, ed.), PARC, Palo Alto, pp. 1-2, 2013.
[bib][url] [pdf] [abstract]
Abstract: This paper shows how adaptive streaming and on-device caching can be used to provide an always available video service. A DASH client has been extended to deal with periods of zero network connectivity, and seamlessly works in conjunction with CCN to provide local storage that is intelligently updated to provide an improved quality of experience.
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[36] | Claudio Alberti, Daniele Renzi, Christian Timmerer, Christopher Mueller, Stefan Lederer, Stefano Battista, Marco Mattavelli, Automated QoE Evaluation of Dynamic Adaptive Streaming over HTTP, In Proceedings of the 5th International Workshop on Quality of Multimedia Experience (QoMEX'13) (Christian Timmerer, Patrick Le Callet, Martin Varela, Stefan Winkler, Tiago Falk, eds.), IEEE, Los Alamitos, CA, USA, pp. 58-63, 2013.
[bib] [pdf] [abstract]
Abstract: Dynamic Adaptive Streaming over HTTP (DASH) is referred to as a multimedia streaming standard to deliver high quality multimedia content over the Internet using conventional HTTP Web servers. As a fundamental feature, it enables automatic switching of quality levels according to network conditions, user requirements, and expectations. Currently, the proposed adaptation schemes for HTTP streaming mostly rely on throughput measurements and/or buffer-related metrics, such as buffer exhaustion and levels. In this paper, we propose to enhance the DASH adaptation logic by feeding it with additional information from our evaluation of the users' perception approximating the user- perceived quality of video playback. The proposed model aims at conveniently combining TCP-, buffer-, and media content-related metrics as well as user requirements and expectations to be used as an input for the DASH adaptation logic. Experiments have demonstrated that the chosen model enhances the capability of the adaptation logic to select the optimal video quality level. Finally, we integrated all our findings into a real DASH system with QoE monitoring capabilities.
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[35] | Markus Waltl, Christian Timmerer, Benjamin Rainer, Hermann Hellwagner, Sensory Effect Dataset and Test Setups, In Proceedings of the 4th International Workshop on Quality of Multimedia Experience (QoMEX'12) (Ian Burnett, Henry Wu, eds.), IEEE, Yarra Valley, Australia, pp. 115-120, 2012.
[bib][url] [pdf] [abstract]
Abstract: Additional constituents for the representation of multimedia content gained more and more attention. For example, the amount of cinemas equipped with additional devices (e.g., ambient light, vibrating seats, wind generators, water sprayers, heater/coolers) that stimulate senses going beyond audition and vision increases. On the content side the MPEG-V standard specifies – among others – Sensory Effect Metadata (SEM) which provides means to describe sensory effects such as wind, vibration, light, etc. to be attached to audio-visual content and, thus, offering an enhanced and immersive experience for the user. However, there is a lack of a common set of test content allowing for various subjective user studies and verification across different test sites. In this paper we provide our dataset comprising a number of videos from different genres enriched with MPEG-V compliant Sensory Effect Metadata descriptions. Furthermore, we describe possible test setups using off-the-shelf hardware for conducting subjective quality assessments.
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[34] | Markus Waltl, Christian Timmerer, Benjamin Rainer, Hermann Hellwagner, Sensory Effects for Ambient Experiences in the World Wide Web, In Multimedia Tools and Applications, Springer Verlag, vol. -, no. -, Berlin, Heidelberg, New York, pp. 1-20, 2012. (Online First)
[bib][url] [doi] [abstract]
Abstract: More and more content in various formats becomes available via the WorldWideWeb (WWW). Currently availableWeb 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) description which is associated to multimedia content and is rendered on devices like fans, vibration chairs, or lamps. In this paper we present two subjective quality assessments which comprise sensory effects, such as light, in the area of the WWW and their results achieved. The first assessment evaluates the influence of light effects on the Quality of Experience (QoE). The second assessment measures the impact of different settings for the color calculation on the viewing experience. Furthermore, we describe a Web browser plug-in for Mozilla Firefox which is able to render such sensory effects that are provided via the WWW.
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[33] | Markus Waltl, Benjamin Rainer, Christian Timmerer, Hermann Hellwagner, Enhancing the User Experience with the Sensory Effect Media Player and AmbientLib, In Advances in Multimedia Modeling (Klaus Schoeffmann, Bernard Merialdo, Alexander Hauptmann, Chong-Wah Ngo, Yiannis Andreopoulos, Christian Breiteneder, eds.), Springer, Berlin, Heidelberg, New York, pp. 624-626, 2012.
[bib] [pdf] [abstract]
Abstract: Multimedia content is increasingly used in every area of our life. Still, each type of content only stimulates the visual and/or the hearing system. Thus, the user experience depends only on those two stimuli. In this paper we introduce a standard which offers the possibility to add additional effects to multimedia content. Furthermore, we present a multimedia player and a Web browser plug-in which uses this standard to stimulate further senses by using additional sensory effects (i.e., wind, vibration, and light) to enhance the user experience resulting in a unique, worthwhile sensory experience.
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[32] | Markus Waltl, Benjamin Rainer, Christian Timmerer, Hermann Hellwagner, A Toolset for the Authoring, Simulation, and Rendering of Sensory Experiences, In Proceedings of the 20th ACM Multimedia (MM'12) (Noboru Babaguchi, Kiyoharu Aizawa, John Smith, eds.), ACM, Nara, Japan, pp. 1469-1472, 2012.
[bib][url] [pdf] [abstract]
Abstract: This paper describes a toolset for the authoring, simulating, and rendering of multimedia content annotated with Sensory Effect Metadata (SEM) descriptions as specified in Part 3 of the MPEG V standard. This part of MPEG-V standardizes the description of sensory effects (e.g., light, wind) in order to be rendered on sensory devices (e.g., fans, vibration chairs) aiming at generating a sensory experience stimulating possibly all human senses. Our implementation comprises a toolset to author sensory effects associated with multimedia content and the simulation thereof. Furthermore, it includes a library, a standalone player, and a Web browser plug-in which enables the playback and rendering of sensory effects on off-the-shelf rendering devices and in various contexts. All software modules are available under the GNU General Public License (GPL) v3 and the GNU Lesser General Public License (LGPL) v3 respectively.
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[31] | Christian Timmerer, Carsten Griwodz, Dynamic adaptive streaming over HTTP: from content creation to consumption, In Proceedings of the 20th ACM international conference on Multimedia (Noboru Babaguchi, Kiyoharu Aizawa, John Smith, eds.), ACM, New York, NY, USA, pp. 1533-1534, 2012.
[bib][url] [doi] [pdf] [slides] [abstract]
Abstract: In this tutorial we present dynamic adaptive streaming over HTTP ranging from content creation to consumption. It particular, it provides an overview of the recently ratified MPEG-DASH standard, how to create content to be delivered using DASH, its consumption, and the evaluation thereof with respect to competing industry solutions. The tutorial can be roughly clustered into three parts. In part I we will provide an introduction to DASH, part II covers content creation, delivery, and consumption, and, finally, part III deals with the evaluation of existing (open source) MPEG-DASH implementations compared to state-of-art deployed industry solutions.
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[30] | Christian Timmerer, Markus Waltl, Benjamin Rainer, Hermann Hellwagner, Assessing the quality of sensory experience for multimedia presentations, In Signal Processing: Image Communication, Elsevier, vol. 27, no. 8, Amsterdam, Netherlands, pp. 909-916, 2012.
[bib][url] [doi] [pdf] [abstract]
Abstract: This paper introduces the concept of sensory experience by utilizing sensory effects such as wind or lighting as another dimension which contributes to the quality of the user experience. In particular, we utilize a representation format for sensory effects that are attached to traditional multimedia resources such as audio, video, and image contents. Sensory effects (e.g., wind, lighting, explosion, heat, cold) are rendered on special devices (e.g., fans, ambient lights, motion chair, air condition) in synchronization with the traditional multimedia resources and shall stimulate other senses than audition and vision (e.g., mechanoreception, equilibrioception, thermoreception), with the intention to increase the users Quality of Experience (QoE). In particular, the paper provides a comprehensive introduction into the concept of sensory experience, its assessment in terms of the QoE, and related standardization and implementation efforts. Finally, we will highlight open issues and research challenges including future work.
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[29] | Benjamin Rainer, Markus Waltl, Eva Cheng, Muawiyath Shujau, Christian Timmerer, Stephen Davis, Ian Burnett, Hermann Hellwagner, Investigating the Impact of Sensory Effects on the Quality of Experience and Emotional Response in Web Videos, In Proceedings of the 4th International Workshop on Quality of Multimedia Experience (QoMEX'12) (Ian Burnett, Henry Wu, eds.), IEEE, Yarra Valley, Australia, pp. 278-283, 2012.
[bib][url] [pdf] [abstract]
Abstract: Multimedia is ubiquitously available online with large amounts of video increasingly consumed through Web sites such as YouTube or Google Video. However, online multimedia typically limits users to visual/auditory stimulus, with onscreen visual media accompanied by audio. The recent introduction of MPEG-V proposed multi-sensory user experiences in multimedia environments, such as enriching video content with so-called sensory effects like wind, vibration, light, etc. In MPEG-V, these sensory effects are represented as Sensory Effect Metadata (SEM), which is additionally associated to the multimedia content. This paper presents three user studies that utilize the sensory effects framework of MPEG-V, investigating the emotional response of users and enhancement of Quality of Experience (QoE) of Web video sequences from a range of genres with and without sensory effects. In particular, the user studies were conducted in Austria and Australia to investigate whether geography and cultural differences affect users’ elicited emotional responses and QoE.
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[28] | Benjamin Rainer, Stefan Lederer, Christopher Mueller, Christian Timmerer, A Seamless Web Integration of Adaptive HTTP streaming, In Proceedings of the 20th European Signal Processing Conference (EUSIPCO) (Béatrice Pesquet-Popescu, Corneliu Burileanu, eds.), European Signal Processing (EURASIP) Society, Bucharest, Romania, pp. 1519-1523, 2012.
[bib] [pdf] [abstract]
Abstract: Nowadays video is an important part of the Web and Web sites like YouTube, Hulu, etc. count millions of users consuming their content every day. However, these Web sites mainly use media players based on proprietary browser plug-ins (i.e., Adobe Flash) and do not leverage adaptive streaming systems. This paper presents a seamless integration of the recent MPEG standard on Dynamic Adaptive Streaming over HTTP (DASH) in the Web using the HTML5 video element. Therefore, we present DASHJS, a JavaScript-based MPEG-DASH client which adopts the Media Source API of Google’s Chrome browser to present a flexible and potentially browser independent DASH client. Furthermore, we present the integration of WebM based media segments in DASH giving a detailed description of the used container format structure and a corresponding Media Presentation Description (MPD). Our preliminary evaluation demonstrates the bandwidth adaption capabilities to show the effectiveness of the system.
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[27] | Christopher Mueller, Daniele Renzi, Stefan Lederer, Stefano Battista, Christian Timmerer, Using Scalable Video Coding for Dynamic Adaptive Streaming over HTTP in Mobile Environments, In Proceedings of the 20th European Signal Processing Conference (EUSIPCO12) (Corneliu Burileanu, Béatrice Pesquet-Popescu, eds.), European Signal Processing (EURASIP) Society, Bucharest, Romania, pp. 2208-2212, 2012.
[bib] [pdf] [abstract]
Abstract: Dynamic Adaptive Streaming over HTTP (DASH) is a convenient approach to transfer videos in an adaptive and dynamic way to the user. As a consequence, this system provides high bandwidth flexibility and is especially suitable for mobile use cases where the bandwidth variations are tremendous. In this paper we have integrated the Scalable Video Coding (SVC) extensions of the Advanced Video Coding (AVC) standard into the recently ratified MPEG-DASH standard. Furthermore, we have evaluated our solution under restricted conditions using bandwidth traces from mobile environments and compared it with an improved version of our MPEG-DASH implementation using AVC as well as major industry solutions.
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[26] | Christopher Mueller, Stefan Lederer, Christian Timmerer, An Evaluation of Dynamic Adaptive Streaming over HTTP in Vehicular Environments, In Proceedings of the Fourth Annual ACM SIGMM Workshop on Mobile Video (MoVid12) (Mohamed Hefeeda, Cheng-Hsin Hsu, Mainak Chatterjee, Nalini Venkatasubramanian, Samrat Ganguly, eds.), ACM, New York, NY, USA, pp. 37-42, 2012.
[bib] [pdf] [abstract]
Abstract: MPEGs' Dynamic Adaptive Streaming over HTTP (MPEG-DASH) is an emerging standard designed for media delivery over the top of existing infrastructures and able to handle varying bandwidth conditions during a streaming session. This requirement is very important, specifically within mobile environments and, thus, DASH could potentially become a major driver for mobile multimedia streaming. Hence, this paper provides a detailed evaluation of our implementation of MPEG DASH compared to the most popular propriety systems, i.e., Microsoft Smooth Steaming, Adobe HTTP Dynamic Streaming, and Apple HTTP Live Streaming. In particular, these systems will be evaluated under restricted conditions which are due to vehicular mobility. In anticipation of the results, our prototype implementation of MPEG-DASH can very well compete with state-of-the-art solutions and, thus, can be regarded as a mature standard ready for industry adaption.
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[25] | Christopher Mueller, Stefan Lederer, Christian Timmerer, A Proxy Effect Analysis and Fair Adaptation Algorithm for Multiple Competing Dynamic Adaptive Streaming over HTTP Clients, In Proceedings of the IEEE Conference on Visual Communications and Image Processing Conference (VCIP 2012) (Kiyoharu Aizawa, Jay Kuo, Zicheng Liu, eds.), IEEE, San Diego, CA, USA, pp. 6, 2012.
[bib][url] [pdf] [abstract]
Abstract: Multimedia streaming technologies based on the Hypertext Transfer Protocol (HTTP) are very popular and used by many content providers such as Netflix, Hulu, and Vudu. Recently, ISO/IEC MPEG has ratified Dynamic Adaptive Streaming over HTTP (DASH) which extends the traditional HTTP streaming with an adaptive component addressing the issue of varying bandwidth conditions that users are facing in networks based on the Internet Protocol (IP). Additionally, industry has already deployed several solutions based on such an approach which simplifies large scale deployment because the whole streaming logic is located at the client. However, these features may introduce drawbacks when multiple clients compete for a network bottleneck due to the fact that the clients are not aware of the network infrastructure such as proxies or other clients. This paper identifies these negative effects and the evaluation thereof using MPEG-DASH and Microsoft Smooth Streaming. Furthermore, we propose a novel adaptation algorithm introducing the concept of fairness regarding a cluster of clients. In anticipation of the results we can conclude that we achieve more efficient bottleneck bandwidth utilization and less quality switches.
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[24] | Stefan Lederer, Christopher Mueller, Christian Timmerer, Dynamic Adaptive Streaming over HTTP Dataset, In Proceedings of the Third Annual ACM SIGMM Conference on Multimedia Systems (MMSys12) (Mark Claypool, Carsten Griwodz, Ketan Mayer-Patel, eds.), ACM, New York, NY, USA, pp. 89-94, 2012.
[bib] [pdf] [abstract]
Abstract: Adaptive HTTP streaming got lot of attention in recent years and with dynamic adaptive streaming over HTTP (DASH) a standard is available. Many papers cover this topic and present their research results, but unfortunately all of them use their own private dataset which – in most cases – is not publicly available. Hence, it is difficult to compare, e.g., adaptation algorithms in an objective way due to the lack of a common dataset which shall be used as basis for such experiments. In this paper, we present our DASH dataset featuring our DASHEncoder, an open source DASH content generation tool. We also provide basic evaluations of the different segment lengths, the influence of HTTP server settings, and, in this context, we show some of the advantages as well as problems of shorter segment lengths.
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[23] | Yaning Liu, Joost Geurts, Benjamin Rainer, Stefan Lederer, Christopher Mueller, Christian Timmerer, DASH over CCN: A CCN use-case for a Social Media based collaborative project, In CCNx Community Meeting (CCNxConn 2012) (Giovanna Carofiglio, ed.), Parc, Sophia Antipolis, pp. 1-1, 2012.
[bib][url] [pdf] |
[22] | Stefan Lederer, Christopher Mueller, Benjamin Rainer, Markus Waltl, Christian Timmerer, An open source MPEG DASH evaluation suite, In Proceedings of the IEEE Conference on Visual Communications and Image Processing Conference (VCIP 2012) (Ebroul Izquierdo, Xin Wang, eds.), IEEE, San Diego, CA, USA, pp. 1-1, 2012.
[bib][url] [pdf] [abstract]
Abstract: In this paper we demonstrate our MPEG-DASH evaluation suite, which comprises several components on the client side as well as on the server side. The major client components are the VLC DASH plugin, libDASH, and DASH-JS, a JavaScript-based DASH client. These tools enable performance tests on various platforms, e.g., Windows and Linux as well as mobile platforms such as Android. Moreover, due to their flexible structure it is possible to integrate adaptation logics and evaluate them under consistent conditions. On the server side we provide the content generation tool DASHEncoder, our MPEG-DASH datasets well as the MPEG-DASH conformance validator.
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[21] | Stefan Lederer, Christopher Mueller, Christian Timmerer, Towards Peer-Assisted Dynamic Adaptive Streaming over HTTP, In Proceedings of the 19th International Packet Video Workshop (PV 2012) (Christine Guillemot, Jacob Chakareski, Eckehard Steinbach, eds.), IEEE, Munich, Germany, pp. 1-6, 2012.
[bib] [pdf] [abstract]
Abstract: This paper presents our peer-assisted Dynamic Adaptive Streaming over HTTP (pDASH) proposal as well as an evaluation based on our DASH simulation environment in comparison to conventional approaches, i.e., non-peer-assisted DASH. Our approach maintains the standard conformance to MPEG-DASH enabling an easy and straightforward way of enhancing a streaming system with peer assistance to reduce the bandwidth and infrastructure requirements of the content/service provider. In anticipation of the results our system achieves a bandwidth reduction of Content Distribution Networks (CDN) and as a consequence the corresponding infrastructure costs of the content/service providers by up to 25% by leveraging the upstream capacity of neighboring peers. Furthermore, the cost savings have been evaluated using a cost model that is based on the current Amazon CloudFront pricing scheme. Furthermore, we have also evaluated the performance impact that various combinations of quality levels of the content could have in a peer-assisted streaming system as well as the client behavior in such an environment.
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[20] | Tobias Hoßfeld, Raimund Schatz, Martin Varela, Christian Timmerer, Challenges of QoE Management for Cloud Applications, In Communications Magazine, IEEE, IEEE Communications Society, vol. 50, no. 4, New York, NY, USA, pp. 28-36, 2012.
[bib] [doi] [pdf] [abstract]
Abstract: Cloud computing is currently gaining enormous momentum due to a number of promised benefits: ease of use in terms of deployment, administration, and maintenance, along with high scalability and flexibility to create new services. However, as more personal and business applications migrate to the cloud, service quality will become an important differentiator between providers. In particular, quality of experience as perceived by users has the potential to become the guiding paradigm for managing quality in the cloud. In this article, we discuss technical challenges emerging from shifting services to the cloud, as well as how this shift impacts QoE and QoE management. Thereby, a particular focus is on multimedia cloud applications. Together with a novel QoE-based classification scheme of cloud applications, these challenges drive the research agenda on QoE management for cloud applications.
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[19] | Michael Grafl, Christian Timmerer, Markus Waltl, George Xilouris, Nikolaos Zotos, Daniele Renzi, Stefano Battista, Alex Chernilov, Distributed Adaptation Decision-Taking Framework and Scalable Video Coding Tunneling for Edge and In-Network Media Adaptation, In Proceedings of the 2012 IEEE International Conference on Telecommunications and Multimedia (TEMU 2012) (Evangelos Pallis, Vassilios Zacharopoulos, Anastasios Kourtis, eds.), IEEE, Los Alamitos, CA, USA, pp. 6, 2012.
[bib] [doi] [pdf] [abstract]
Abstract: Existing and future media ecosystems need to cope with the ever-increasing heterogeneity of networks, devices, and user characteristics collectively referred to as (usage) context. The key to address this problem is media adaptation to various and dynamically changing contexts in order to provide a service quality that is regarded as satisfactory by the end user. The adaptation can be performed in many ways and at different locations, e.g., at the edge and within the network resulting in a substantial number of issues to be integrated within a media ecosystem. This paper describes research challenges, key innovations, target research outcomes, and achievements so far for edge and in-network media adaptation by introducing the concept of Scalable Video Coding (SVC) tunneling.
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[18] | 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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[17] | 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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[16] | 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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[15] | 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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[14] | 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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[13] | 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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