Abstract: Social networks have become ubiquitous and with these new possible ways for social communication and experiencing multimedia together the traditional TV scenario drifts more and more towards a distributed social experience. Asynchronism in the multimedia playback of the users may have a significant impact on the acceptability of systems providing the distributed multimedia experience. The synchronization needed in such systems is called Inter-Destination Multimedia Synchronization. In this paper we propose a demo that implements IDMS by the means of our self-organized and distributed approach assisted by pull-based streaming. We also provide a video of the planned demonstration and provide the mobile application as open source licensed under the GNU LGPL.

Abstract: Inter-destination multimedia synchronization and quality of experience are critical to the success of social TV, which integrates television viewing with social networking.

Abstract: In this tutorial we present state of the art and challenges ahead in over-the-top content delivery. It particular, the goal of this tutorial is to provide an overview of adaptive media delivery, specifically in the context of HTTP adaptive streaming (HAS) including the recently ratified MPEG-DASH standard. The main focus of the tutorial will be on the common problems in HAS deployments such as client design, QoE optimization, multi-screen and hybrid delivery scenarios, and synchronization issues. For each problem, we will examine proposed solutions along with their pros and cons. In the last part of the tutorial, we will look into the open issues and review the work-in-progress and future research directions.

Abstract: This chapter introduces the concept of Sensory Experience which aims to define the Quality of Experience (QoE) going beyond audio-visual content. In particular, we show how to utilize sensory effects such as ambient light, scent, wind, or vibration as additional dimensions contributing to the quality of the user experience. Therefore, we utilize a standardized representation format for sensory effects that are attached to traditional multimedia resources such as audio, video, and image contents. Sensory effects are rendered on special devices (e.g., fans, lights, motion chair, scent emitter) in synchronization with the traditional multimedia resources and shall stimulate also other senses than hearing and seeing with the intention to increase the Quality of Experience (QoE), in this context referred to as Sensory Experience.

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.

Abstract: Mobile peer-to-peer (P2P) computing with applications such as for video on demand, file sharing, and video conferencing is gaining momentum based on new standards and technologies such as IETF PPSP, WiFi-Direct and BitTorrent live streaming. In this paper, we describe the mobile system MyMedia, that allows users to search, share and experience videos and live recordings using P2P and at the best quality possible with respect to available network capacity. In particular, the MyMedia system features a high-precision semantic P2P search and dynamic network-adaptive P2P live streaming of MPEG videos over HTTP based on the ISO/IEC standard MPEG-DASH from mobile to mobile devices in unstructured wireless P2P networks. These features have been integrated in the mobile application TIFF EventLive of the 54th Thessaloniki international film festival. The evaluation of their performance and device energy consumption, and a first user evaluation at the festival showed that the MyMedia system is suitable and accepted by users for its purpose in practice. The MyMedia system is available as open-source software for the Android operating system.

Abstract: Social networks have become pervasive and have changed the way of social interaction. The traditional TV experience drifts from an event tied to a certain place with the family or friends to a location-independent and distributed social experience. Additionally, more and more video on-demand services adopt a pull-based streaming approach. In order to provide a synchronized and distributed TV experience we introduce a self-organized Inter-Destination Multimedia Synchronization (IDMS) framework for adaptive media streaming. In particular, we extend the principles of IDMS to adaptive media streaming over HTTP (i.e., MPEG-DASH) and enable a synchronized multimedia playback among geographically distributed clients. Therefore, we introduce session management to MPEG-DASH and for negotiating on a reference playback timestamp among the participating peers in an IDMS session we propose a distributed control scheme. We evaluate our proposed scheme with respect to scalability and time required for negotiating on the reference playback timestamp. Furthermore, we investigate how to compensate the identified asynchronism by using adaptive media playout with respect to the Quality of Experience (QoE). Therefore, we define a temporal distortion measure for audio and video which allows us to model the impact of playback rate variations on the QoE. This measure is evaluated by conducting a subjective quality assessment using crowdsourcing.

Abstract: In the past decade Adaptive Media Playout (AMP) has been intensively studied with respect to the detection of when to increase or decrease the playback rate in order to maintain a certain buffer fill state. In this paper we subjectively assess the QoE of AMP with respect to non-periodically and randomly selected content sections of a video sequence by us- ing crowdsourcing. Furthermore, we introduce features that allow to quantify the distortion for audio and video that are caused by increasing or decreasing the playback rate. With these preliminaries we study the correlation between the introduced features and the subjectively assessed QoE. Therefore, we derive a utility model that allows to estimate the QoE with the introduced features. We instantiate and validate the model by the use of the data gathered by the conducted study.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.