[256] | Tobias Hoßfeld, Christian Keimel, Christian Timmerer, Crowdsourcing Quality-of-Experience Assessments, In Computer, IEEE Computer Society, vol. 47, no. 9, Los Alamitos, CA, USA, pp. 98-102, 2014.
[bib] [doi] [pdf] [abstract]
Abstract: Crowdsourced quality-of-experience (QoE) assessments are more cost-effective and flexible than traditional in-lab evaluations but require careful test design, innovative incentive mechanisms, and technical expertise to address various implementation challenges.
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[255] | Tobias Hoßfeld, Matthias Hirth, Pavel Korshunov, Philippe Hanhart, Bruno Gardlo, Christian Keimel, Christian Timmerer, Survey of Web-based Crowdsourcing Frameworks for Subjective Quality Assessment, In 2014 IEEE International Workshop on Multimedia Signal Processing (MMSP 2014) (Susanto Rahardja, Zhengyou Zhang, Fernando Pereira, Alexander Loui, eds.), IEEE, Piscataway, N.J. 08854, U.S.A., pp. 6, 2014.
[bib] [pdf] [abstract]
Abstract: The popularity of the crowdsourcing for performing various tasks online increased significantly in the past few years. The low cost and flexibility of crowdsourcing, in particular, attracted researchers in the field of subjective multimedia evalua- tions and Quality of Experience (QoE). Since online assessment of multimedia content is challenging, several dedicated frameworks were created to aid in the designing of the tests, including the support of the testing methodologies like ACR, DCR, and PC, setting up the tasks, training sessions, screening of the subjects, and storage of the resulted data. In this paper, we focus on the web-based frameworks for multimedia quality assessments that support commonly used crowdsourcing platforms such as Amazon Mechanical Turk and Microworkers. We provide a detailed overview of the crowdsourcing frameworks and evaluate them to aid researchers in the field of QoE assessment in the selection of frameworks and crowdsourcing platforms that are adequate for their experiments.
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[254] | Gheorghita Ghinea, Christian Timmerer, Weisi Lin, Stephen Gulliver, Mulsemedia: State of the Art, Perspectives, and Challenges, In ACM Transactions on Multimedia Computing, Communications, and Applications (TOMM), ACM, vol. 11, no. 1s, New York, NY, USA, pp. 17:1-17:23, 2014.
[bib] [pdf] [abstract]
Abstract: Mulsemedia—multiple sensorial media—captures a wide variety of research efforts and applications. This article presents a historic perspective on mulsemedia work and reviews current developments in the area. These take place across the traditional multimedia spectrum—from virtual reality applications to computer games—as well as efforts in the arts, gastronomy, and therapy, to mention a few. We also describe standardization efforts, via the MPEG-V standard, and identify future developments and exciting challenges the community needs to overcome.
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[253] | Gheorghita Ghinea, Christian Timmerer, Weisi Lin, Stephen Gulliver, Guest Editorial: Special Issue on Multiple Sensorial (MulSeMedia) Multimodal Media: Advances and Applications, In ACM Transactions on Multimedia Computing, Communications, and Applications (TOMM), ACM, vol. 11, no. 1s, New York, NY, USA, pp. 9:1-9:2, 2014.
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[252] | Markus Waltl, Benjamin Rainer, Stefan Lederer, Christian Timmerer, Katharina Gassner, Ralf Terlutter, A 4D Multimedia Player enabling Sensory Experience, In Proceedings of the 5th International Workshop on Quality of Multimedia Experience (QoMEX'13) (Christian Timmerer, Patrick Le Callet, Martin Varela, Stefan Winkler, Tiago H Falk, eds.), IEEE, Los Alamitos, CA, USA, pp. 126-127, 2013.
[bib][url] [pdf] [abstract]
Abstract: Lately, 3D is gaining momentum in cinemas and home environments. However, 2D and 3D video content only stimulates senses like hearing and seeing. In this paper we focus on a more enhanced level of entertainment by presenting a 4D multimedia player and a corresponding demonstration setup, which stimulates further senses such as haptics using the MPEG-V: Media Context and Control standard. The presented demonstration setup uses stereoscopic 3D and sensory devices, i.e., fans, vibration panels and lights. The combination of conventional 3D content with tailored sensory effects allows us to further enhance the viewing experience of the users.
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[251] | Markus Waltl, The Impact of Sensory Effects on the Quality of Multimedia Experience, PhD thesis, Alpen-Adria-Universität Klagenfurt, pp. 234, 2013.
[bib] [pdf] [abstract]
Abstract: Multimedia content is omnipresent in our life. Thus, one can consume content through various distribution channels such as a DVD, Blu-Ray, or the Internet. Recently, 3D video gained more and more importance and a lot of movies presented in cinemas are 3D. Currently, research on additional constituents such as light and scent effects for further enhancing the viewing experience is conducted. As this research is taken up by more and more researchers and companies, the Moving Picture Experts Group (MPEG) ratified the MPEG-V standard, referred to as Media Context and Control, which allows the annotation of multimedia content with additional effects (e.g., light, wind, vibration) and render these effects synchronized to the multimedia content. Due to this fairly new research area, there are only a few subjective quality assessments evaluating such effects. Moreover, standardized assessment methods cannot be used as originally developed since they are optimized for audio-visual quality evaluations. Thus, this work lists and describes existing subjective quality assessment methods suitable for conducting assessments comprising multimedia content, especially videos, enriched by sensory effects (i.e., light, wind, and vibration). As there is a lack of suitable software for rendering sensory effects, this work introduces a multimedia player for playing multimedia content accompanied by sensory effects. Moreover, in this work, we performed four subjective quality assessments answering the following questions: (1) Do sensory effects enhance the viewing experience for different genres? (2) Do sensory effects have an influence on the perceived video quality? (3) Do light effects enhance the viewing experience for Web videos? (4) Do sensory effects have an impact on the perceived emotions while watching a video? Therefore, this work presents these subjective quality assessments including a detailed description of the assessments and their results. Moreover, this work introduces a dataset consisting of video sequences annotated with sensory effects for conducting subjective quality assessments. Finally, some recommendations for performing assessments comprising sensory effects which have been extracted from the conducted subjective quality assessments are given.
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[250] | Markus Waltl, Benjamin Rainer, Christian Timmerer, Hermann Hellwagner, An End-to-End tool chain for sensory experience based on MPEG-V, In Signal Processing: Image Communication, Elsevier, vol. 28, no. 2, Amsterdam, Netherlands, pp. 136-150, 2013.
[bib][url] [doi] [abstract]
Abstract: This paper provides an overview of our research conducted in the area of Sensory Experience including our implementations using MPEG-V Part 3 entitled ”Sensory Information”. MPEG-V Part 3 introduces Sensory Experience as a tool to increase the Quality of Experience by annotating traditional multimedia data with sensory effects. These sensory effects are rendered on special devices like fans, vibration chairs, ambient lights, scent disposers, water sprayers, or heating/cooling devices stimulating senses beyond the traditional ones. The paper's main focus is on the end-to-end aspects including the generation, transmission, and synchronized rendering of sensory effects with the traditional multimedia data taking movie clips as an example. Therefore, we present in this paper an open source tool chain that provides a complete end-to-end sensory effect generation and consumption framework. Furthermore, we summarize results from various subjective quality assessments conducted in this area. Finally, we point out research challenges that may encourage further research within this emerging domain.
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[249] | Christian Timmerer, Benjamin Rainer, Waltl Markus, A Utility Model for Sensory Experience, In Proceedings of the 5th International Workshop on Quality of Multimedia Experience (QoMEX'13) (Christian Timmerer, Patrick Le Callet, Martin Varela, Stefan Winkler, Tiago H Falk, eds.), IEEE, Los Alamitos, CA, USA, pp. 224-229, 2013.
[bib][url] [pdf] [abstract]
Abstract: Enriching multimedia with additional effects such as olfaction, light, wind, or vibration is gaining more and more momentum in both research and industry. Hence, there is the need to determine the influence of individual effects on the Quality of Experience (QoE). In this paper, we present a subjective quality assessment using the MPEG-V standard to annotate video sequences with individual sensory effects (i.e., wind, light, and vibration) and all combinations thereof. Based on the results we derive a utility model for sensory experience that accounts for the assessed sensory effects. Finally, we provide an example instantiation of the utility model and validate it against current and past results of our subjective quality assessments conducted so far.
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[248] | Christian Timmerer, MPEG Column: 105th MPEG Meeting, In ACM SIGMultimedia Records, ACM, vol. 5, no. 3, New York, NY, USA, pp. 1-2, 2013.
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[247] | Christian Timmerer, MPEG column: 103rd MPEG meeting, In ACM SIGMultimedia Records, ACM, vol. 5, no. 1, New York, NY, USA, pp. 1-3, 2013.
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[246] | Christian Timmerer, MPEG Column: 106th MPEG Meeting, In ACM SIGMultimedia Records, ACM, vol. 5, no. 4, New York, NY, USA, pp. 1-2, 2013.
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[245] | Christian Timmerer, Anthony Vetro, Recent MPEG Standards for Future Media Ecosystems, In Computing Now, IEEE Computer Society [online], vol. 6, no. 10, Los Alamitos, CA, USA, pp. 1, 2013.
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[244] | Christian Sieber, Tobias Hoßfeld, Thomas Zinner, Phuoc Tran-Gia, Christian Timmerer, Implementation and User-centric Comparison of a Novel Adaptation Logic for DASH with SVC, In Integrated Network Management (IM 2013), 2013 IFIP/IEEE International Symposium on (Filip De Turck, Yixin Diao, Choong Seon Hong, Deep Medhi, Ramin Sadre, eds.), IEEE Communications Society, New York, NY, USA, pp. 1318-1323, 2013.
[bib] [pdf] [abstract]
Abstract: The MPEG-DASH standard allows the client-centric access to different representations of video content via the HTTP protocol. The client can flexibly switch between different qualities, i.e., different bit rates and thus avoid waiting times during the video playback due to empty playback buffers. However, quality switches and the playback of lower qualities is perceived by the user which may reduce the Quality of Experience (QoE). Therefore, novel algorithms are required which manage the streaming behavior with respect to the user's requirements and which do not waste network resources. As indicated by recent studies, scalable video coding (SVC) may use the current network and content distribution infrastructure in a more efficient way than with single layer codecs. The contribution of this paper is the design and the implementation of a novel DASH/SVC streaming algorithm. By means of measurements in a test-bed, its performance and benefits are evaluated and compared to existing algorithms from an user-centric view point with objective performance metrics. Our findings show that the proposed algorithm outperforms other DASH mechanisms in terms of video quality, low switching frequency and usage of the available resources in a realistic mobile network scenario. This is a first step towards true QoE management of video streaming in the Internet with DASH and SVC.
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[243] | Benjamin Rainer, Christian Timmerer, Markus Waltl, Recommendations for the Subjective Evaluation of Sensory Experience, In 4th International Workshop on Perceptual Quality of Systems 2013 (PQS 2013) (Raimund Schatz, ed.), IEEE, Vienna, Austria, pp. 1-6, 2013.
[bib] [abstract]
Abstract: Selecting and adopting the appropriate assessment method for conducting subjective quality assessments is a challenging task. The method decides whether the assessment is successful in delivering the correct answers to previously set up hypotheses. Therefore, in this paper we provide recommendations on test methods used in the domain of Sensory Experience. The proposed test methods comprise single stimulus and double stimulus methods. These test methods were used in previous studies and are presented in combination with the results of the subjective quality assessments with which they were used. Furthermore, we briefly outline our test setup, test design, and test content for assessing Sensory Experience which have been validated through conducted assessments.
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[242] | Benjamin Rainer, Christian Timmerer, Adaptive Media Playout for Inter-Destination Media Synchronization, In Proceedings of the 5th International Workshop on Quality of Multimedia Experience (QoMEX'13) (Christian Timmerer, Patrick Le Callet, Martin Varela, Stefan Winkler, Tiago H Falk, eds.), IEEE, Los Alamitos, CA, USA, pp. 44-45, 2013.
[bib][url] [pdf] [abstract]
Abstract: Synchronizing multimedia playback among geographically distributed clients is a challenging task and is referred to as Inter-Destination Media Synchronization (IDMS). In this paper we discuss the uses cases of IDMS as identified within the SocialSensor Project and based on these use cases we derive a novel Adaptive Media Playout (AMP) scheme which aims on carrying out the process of synchronizing the media playback at the clients to a given synchronization point. We propose how visual and acoustic features can be used to achieve a QoE-aware and context-aware AMP scheme.
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[241] | Benjamin Rainer, Markus Waltl, Christian Timmerer, A Web based Subjective Evaluation Platform, In Proceedings of the 5th International Workshop on Quality of Multimedia Experience (QoMEX'13) (Christian Timmerer, Patrick Le Callet, Martin Varela, Stefan Winkler, Tiago H Falk, eds.), IEEE, Los Alamitos, CA, USA, pp. 24-25, 2013.
[bib][url] [pdf] [abstract]
Abstract: Preparing and conducting subjective quality assessments is a time consuming and expensive task. Therefore, we present a Web-based evaluation framework which aims on reducing the time needed for planning and designing a subjective quality assessment. The presented framework can be used for both crowdsourced and laboratory experiments. It should ease the task of designing a subjective quality assessment by providing a flexible framework. The framework has proven its applicability and flexibility to design and conduct assessments in the past and is available as open source.
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[240] | Christian Raffelsberger, Hermann Hellwagner, A Hybrid MANET-DTN Routing Scheme For Emergency Response Scenarios, In Proceedings of the Eleventh IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops '13) (Jadwiga Indulska, Chatschik Bisdikian, eds.), IEEE, Los Alamitos, CA, USA, pp. 505-510, 2013.
[bib] [pdf] [abstract]
Abstract: Emergency response operations are a promising application area for mobile ad-hoc networks (MANETs). Most existing MANET routing protocols assume that an end-toend path between source and destination can be established. However, this assumption may not hold in a hastily formed network established during an emergency response. This paper evaluates a store-and-forward mechanism for proactive routing protocols to mitigate the effects of network disruptions. The mechanism is integrated into two routing protocols. The modified protocols are evaluated in an emergency response scenario that includes a disaster area mobility model and a wireless obstacle model. The scenario represents a realistic first responder operation after an incident in a chemical facility. The evaluation results show that networks for disaster responses benefit from the modified routing protocols.
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[239] | Christian Raffelsberger, Hermann Hellwagner, Overview of Hybrid MANET-DTN Networking and its Potential for Emergency Response Operations, In Proceedings of the Combined workshop on Self-organizing, Adaptive, and Context-Sensitive Distributed Systems and Self-organized Communication in Disaster Scenarios (SACS/SoCoDiS '13) (Michael Zapf, Florian Evers, eds.), Electronic Communications of the EASST (ECEASST), Berlin, Germany, pp. 1 -12, 2013.
[bib] [pdf] [abstract]
Abstract: Communication networks for emergency response operations have to operate in harsh environments. As fixed infrastructures may be unavailable (e.g., they are destroyed or overloaded), mobile ad-hoc networks (MANETs) are a promising solution to establish communication for emergency response operations. However, networks for emergency responses may provide diverse connectivity characteristics which imposes some challenges, especially on routing. Routing protocols need to take transmission errors, node failures and even the partitioning of the network into account. Thus, there is a need for routing algorithms that provide mechanisms from Delay or Disruption Tolerant Networking (DTN) in order to cope with network disruptions but at the same time are as efficient as MANET routing schemes in order to preserve network resources. This paper reviews several hybrid MANET-DTN routing schemes that can be found in the literature. Additionally, the paper evaluates a realistic emergency response scenario and shows that MANET-DTN routing schemes have the potential to improve network performance as the resulting network is diverse in terms of connectivity. In particular, the network provides well-connected regions whereas other parts are only intermittently connected.
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[238] | Daniel Posch, Hermann Hellwagner, Peter Schartner, On-Demand Video Streaming based on Dynamic Adaptive Encrypted Content Chunks, In Proceedings of the 8th International Workshop on Secure Network Protocols (NPSec' 13) (Jun Li, Olaf Maennel, eds.), IEEE, Los Alamitos, CA, USA, pp. 6, 2013.
[bib] [pdf] [abstract]
Abstract: This paper proposes a framework for on-demand video streaming that enables secure and efficient delivery of data towards the end user. Our proposal requires the combined usage of three different technologies. The first one is a recent proposal by Jacobsen et al. called Content-Centric Networking (also known as Named Data Networking). It is a network architecture that introduces named data as the most valuable element in the network and divides it into so called content chunks, which are self-identifying and self-authenticating data units. The second concept we utilize derives from the approach of Dynamic Adaptive Streaming over HTTP, which allows clients to dynamically choose the quality of the received video stream according to their available resources. Finally, we adapt the concept of Broadcast Encryption to form a tool to control the access to provided content streams. The combination of these technologies enables us to design a framework that allows streaming providers to transport data to customers as dynamic adaptive encrypted content chunks, which is an efficient, flexible and scalable way of multimedia data transport.
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[237] | Daniela Pohl, Abdelhamid Bouchachia, Hermann Hellwagner, Social Media for Crisis Management: Clustering Approaches for Sub-Event Detection, In Multimedia Tools and Applications, Springer US, Springer, NY, US, pp. 1-32, 2013.
[bib] |
[236] | Daniela Pohl, Abdelhamid Bouchachia, Financial Time Series Processing: A Roadmap of Online and Offline Methods, Chapter in Business Intelligence and Performance Management (Peter Rausch, Alaa F Sheta, Aladdin Ayesh, eds.), Springer London, London, UK, pp. 145-162, 2013.
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[235] | Christopher Mueller, Stefan Lederer, Jörg Pöcher, Christian Timmerer, libdash – An Open Source Software Library for the MPEG-DASH Standard, In In Proceedings of the IEEE International Conference on Multimedia and Expo (ICME) 2013 (Antonio Servetti, Alatan Aydin, eds.), IEEE, San Jose, USA, pp. 1-2, 2013.
[bib] [pdf] [abstract]
Abstract: Dynamic Adaptive Streaming over HTTP (DASH) is an ISO/IEC MPEG standard which enables the convenient and smooth transportation of multimedia data to heterogeneous end devices over networks with variable bandwidth conditions. This kind of streaming technology is mainly used with HTTP 1.0 and 1.1 respectively, which both have some drawbacks. Therefore, the IETF has started the development of HTTP 2.0, which is based on Google’s SPDY proposal and already supported by several major companies, e.g., Facebook, Twitter, Akamai, Mozilla and obviously Google. Furthermore, Content Centric Networking (CCN) is another novel approach for future networks that is considered as an revolutionary approach compared to HTTP 2.0. The CCN communication paradigm is completely different and does not rely on direct connections between hosts, it rather focuses on the content. This paper demonstrates DASH with HTTP 2.0/SPDY and CCN using our universal libdash library. Moreover, different mechanisms of DASH will be shown that can be used to provide on-demand and live content in an efficient and comfortable way.
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[234] | Christopher Mueller, Stefan Lederer, Christian Timmerer, Fair Share Dynamic Adaptive Streaming over HTTP, In IEEE Multimedia Communications Technical Committee E-Letter, IEEE Communications Society [online], vol. 8, no. 2, New York, NY, USA, pp. 30-33, 2013.
[bib][url] [pdf] [abstract]
Abstract: Multimedia delivery over the Hypertext Transfer Protocol (HTTP) is currently very popular and with MPEGs' Dynamic Adaptive Streaming over HTTP (DASH) a standard is available to provide interoperability and enable large-scale deployments using existing infrastructures (servers, proxies, caches, etc.). This paper identifies some issue when multiple DASH clients compete for a bandwidth bottleneck when transparent proxy caches are deployed. Therefore, we propose a fair share adaptation scheme to be included within the client which – through experimental results – achieve a more efficient utilization of the bottleneck bandwidth and less quality switches.
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[233] | Christopher Mueller, Stefan Lederer, Christian Timmerer, Hermann Hellwagner, Dynamic Adaptive Streaming over HTTP/2.0, In In Proceedings of the IEEE International Conference on Multimedia and Expo (ICME) 2013 (Jin Li, ed.), IEEE, San Jose, USA, pp. 1-6, 2013.
[bib] [pdf] [abstract]
Abstract: MPEG Dynamic Adaptive Streaming over HTTP (DASH) is a new streaming standard that has been recently ratified as an international standard (IS). In comparison to other streaming systems, e.g., HTTP progressive download, DASH is able to handle varying bandwidth conditions providing smooth streaming. Furthermore, it enables NAT and Firewall traversal, flexible and scalable deployment as well as reduced infrastructure costs due to the reuse of existing Internet infrastructure components, e.g., proxies, caches, and Content Distribution Networks (CDN). Recently, the Hypertext Transfer Protocol Bis (httpbis) working group of the IETF has officially started the development of HTTP 2.0. Initially three major proposals have been submitted to the IETF i.e., Googles' SPDY, Microsofts' HTTP Speed+Mobility and Network-Friendly HTTP Upgrade, but SPDY has been chosen as working draft for HTTP 2.0. In this paper we implemented MPEG-DASH over HTTP 2.0 (i.e., SPDY), demonstrating its potential benefits and drawbacks. Moreover, several experimental evaluations have been performed that compare HTTP 2.0 with HTTP 1.1 and HTTP 1.0 in the context of DASH. In particular, the protocol overhead, the performance for different round trip times, and DASH with HTTP 2.0 in a lab test scenario has been evaluated in detail.
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[232] | Stefan Lederer, Christopher Mueller, Benjamin Rainer, Christian Timmerer, Hermann Hellwagner, An Experimental Analysis of Dynamic Adaptive Streaming over HTTP in Content Centric Networks, In Proceedings of the IEEE International Conference on Multimedia and Expo (ICME) 2013 (Haohong Wang, ed.), IEEE, San Jose, USA, pp. 1-6, 2013.
[bib] [pdf] [abstract]
Abstract: This paper presents the usage of CCN, which is a candidate for the next-generation Internet, in combination with the new Dynamic Adaptive Streaming over HTTP (DASH) standard, which was recently ratified by ISO/IEC MPEG. In contrast to the Internet Protocol, which is mainly based on the host-to-host connection paradigm originated in the 1970s, Content Centric Networking (CCN) focuses on the content itself, instead of its location. Considering the dominance of multimedia traffic in todays' Internet, the streaming performance of DASH over CCN as well as the problems introduced by this combination is worth to be investigated in detail. Therefore, we evaluate the protocol overhead introduced by the usage of CCN compared to the HTTP versions 1.0 and 1.1. Furthermore, the performance of DASH over CCN under different network conditions is compared to the performance of HTTP 1.0/1.1. Our results showed that although CCN comes together with higher protocol overhead than HTTP 1.0/1.1 as well as a prototype implementation, it can definitely compete with HTTP 1.0 in media streaming. Based on the evaluation results, problems as well as improvement possibilities are identified, which are the basis for future work in this area.
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