Abstract: Multimedia content delivery and real-time streaming over the top of the existing infrastructure is nowadays part and parcel of every media ecosystem thanks to open standards and the adoption of the Hypertext Transfer Protocol (HTTP) as its primary mean for transportation. Hardware encoder manufacturers have adopted their product lines to support the dynamic adaptive streaming over HTTP but suffer from the inflexibility to provide scalability on demand, specifically for event-based live services that are only offered for a limited period of time. The cloud computing paradigm allows for this kind of flexibility and provide the necessary elasticity in order to easily scale with the demand required for such use case scenarios. In this paper we describe bitcodin, our transcoding and streaming-as-as-ervice platform based on open standards (i.e., MPEG-DASH) which is deployed on standard cloud and content delivery infrastructures to enable high-quality streaming to heterogeneous clients. It is currently deployed for video on demand, 24/7 live, and event-based live services using bitdash, our adaptive client framework.

Abstract: Our approach to automatically separating compound figures appearing in biomedical articles is split into two image processing algorithms: one is based on detecting separator edges, and the other tries to identify background bands separating subgures. Only one algorithm is applied to a given image, according to the prediction of a binary classifier trained to distinguish graphical illustrations from other images in biomedical articles. Our submission to the ImageCLEF 2015 compound figure separation task achieved an accuracy of 49% on the provided test set of about 3400 compound images. This stays clearly behind the best submission of other participants (85% accuracy), but is by an order of magnitude faster than other approaches reported in the literature.

Abstract: We propose a new interface that facilitates content navigation in videos on devices with touchscreen interaction. This interface allows both coarse-grained and fine-grained navigation in an intuitive way and enables better performance when used to locate specific scenes in videos. We implemented this interface on a 5.5-inch smartphone and tested it with 24 users.Our results show that for video navigation tasks the proposed interface significantly outperforms the seeker-bar interface, commonly used with video players on mobile devices. Moreover, we found that the interaction concept of the Scrubbing Wheel has a much lower perceived workload than the widely used seeker-bar, and is the preferred tool to locate scenes in videos for all tested users in our study.

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: Modern-age technology enables us to consume multimedia for enjoyment and as a social experience. The traditional way to consume multimedia together (e.g., with family or friends in the living room) is being superseded by a location-independent scenario where geographically distributed users consume the same content while having a real-time communication channel among each other. Inter-Destination Multimedia Synchronization (IDMS) is the tool of choice in order to enable users a high-quality multimedia experience. In this paper, we investigate the influence of asynchronism when consuming multimedia content together while being geographically distributed. In particular, we adopt the concept of human computation and developed a reaction game which we used to conduct a crowdsourced subjective quality assessment in order to evaluate a threshold for multimedia synchronization within an IDMS scenario. Our results show a significant decrease in overall Quality of Experience (QOE) at an asynchronism level of 750ms. At the same time, we were able to show that asynchronism at a level of 400ms does not have significant differences regarding the QoE when compared to the synchronous reference case.

Abstract: Multimedia delivery systems and protocols usually assume end-to-end connections and low delivery delays between multimedia sources and consumers. However, neither of these two properties can always be achieved in hastily formed networks for emergency response operations. In particular, disruptions may break end-to-end connections, which makes it impossible to deliver multimedia content instantly. This work presents a multimedia delivery system that can operate in disrupted networks and hence may help improve the situational awareness in emergency response operations. The multimedia delivery system is based on HTTP adaptive streaming (HAS) and uses a modified version of HTTP which is able to deliver data in partitioned networks. The multimedia delivery system is evaluated in a realistic emergency response scenario.

Abstract: In medical endoscopy more and more surgeons record videos of their interventions in a long-term storage archive for later retrieval. In order to allow content-based search in such endoscopic video archives, the video data needs to be indexed first. However, even the very basic step of content-based indexing, namely content segmentation, is already very challenging due to the special characteristics of such video data. Therefore, we propose to use instrument classification to enable semantic segmentation of laparoscopic videos. In this paper, we evaluate the performance of such an instrument classification approach. Our results show satisfying performance for all instruments used in our evaluation.

Abstract: Streaming multimedia over the Internet is omnipresent but still in its infancy, specifically when it comes to the adaptation based on bandwidth/throughput measurements, clients competing for limited/shared bandwidth, and the presence of a caching infrastructure. In this paper we present a buffer-based adaptation logic in combination with a toolset of client metrics to compensate for erroneous adaptation decisions. These erroneous adaptation decisions are due to insufficient network information available at the client and issues introduced when multiple clients compete for limited/shared bandwidth and/or when caches are deployed. Our metrics enable the detection of oscillations on the client - in contrast to server-based approaches - and provide an effective compensation mechanism. We evaluate the proposed adaptation logic, which incorporates the oscillation detection and compensation method, and compare it against a throughput-based adaptation logic for scenarios comprising competing clients with and without caching enabled. In anticipation of the results, we show how the presented metrics detect oscillation periods and how such undesirable situations can be compensated while increasing the effective media throughput of the clients.

Abstract: The focus of our research is on improving mobile image and video browsing interfaces. To get a better idea about real world mobile photo and video scenarios and to base our research on real world numbers we performed a survey of photo and video usage on smartphones and tablets. In an online survey we asked 215 participants of the German speaking region about their mobile image collections, their usage patterns, and their motives and intentions when capturing photos. Our results show, among other things, that users store considerable more photos on smartphones than on tablets, that the majority of our participants use their smartphone as primary camera and that users are unlikely to organize their photos on their mobile devices in any way. Moreover, the most popular motives are people, holiday photos, events, and landscapes. Furthermore, it is more popular to capture photos for private than for sharing purposes. We also report about various correlation hypothesis that we tested in the gathered data.

Abstract: The Internet is nowadays mainly used for streaming of multimedia content, something it was not built for originally. To guarantee user satisfaction, one of the key concepts of the Internet as we know it is bandwidth sharing. While this concept is necessary to provide stability in the network, several issues can arise with adaptive multimedia streaming, e.g., efficiency and stability. Considering Information-Centric Networking (ICN) and its network-inherent caching, those issues tend to become worse. Many researchers have proposed to use traffic shaping on the server to enable fair bandwidth sharing and stabilize clients. However, existing research does not consider content popularity and in-network caching. The contribution of this paper is two-fold. First, we propose a cache-aware traffic shaping policy, in order to guarantee seamless playback of videos. Second, based on content popularity, we calculate an average video quality achieved by this traffic shaping policy for various cache sizes, to show the impact of popularity and caching for multimedia streaming in ICN.

Abstract: With video streaming becoming more and more popular, the number of devices that are capable of streaming videos over the Internet is growing. This leads to a heterogeneous device landscape with varying demands. Dynamic Adaptive Streaming over HTTP (DASH) offers an elegant solution to these demands. Smart adaptation logics are able to adjust the clients' streaming quality according to several (local) parameters. Recent research indicated benefits of blending Scalable Video Coding (SVC) with DASH, especially considering Future Internet architectures. However, except for a DASH dataset with a single SVC encoded video, no other datasets are publicly available. The contribution of this paper is two-fold. First, a DASH/SVC dataset, containing multiple videos at varying bitrates and spatial resolutions including 1080p, is presented. Second, a toolchain for multiplexing SVC encoded videos is provided, therefore making our results reproducible and allowing researchers to generate their own datasets.

Abstract: The core problem for any adaptive video streaming solution, particularly over wireless networks, is the detection (or even prediction) of congestion. IEEE 802.11 is especially vulnerable to fast movement and change of antenna orientation. When used in UAV networks (Unmanned Aerial Vehicles), the network throughput can vary widely and is almost impossible to predict. this paper evaluates an approach originally developed by Kofler for home networks, in a single-hop UAV wireless network setting: the delay between the sending of an IEEE 802.11 packet and the receipt of its corresponding acknowledgement is used as an early indicator of the link quality and as a trigger to adapt (reduce or increase) the video stream' s bitrate. Our real-world flight-tests indicate, that this avoids congestion and can frequently avoid the complete loss of video pictures which happens without adaptation.

Abstract: In the field of medical endoscopy more and more surgeons are changing over to record and store videos of their endoscopic procedures, such as surgeries and examinations, in long-term video archives. In order to support surgeons in accessing these endoscopic video archives in a content-based way, we propose a simple yet effective signature-based approach: the Signature Matching Distance based on adaptive-binning feature signatures. The proposed distance-based similarity model facilitates an adaptive representation of the visual properties of endoscopic images and allows for matching these properties efficiently. We conduct an extensive performance analysis with respect to the task of linking specific endoscopic images with video segments and show the high efficacy of our approach. We are able to link more than 88% of the endoscopic images to their corresponding correct video segments, which improves the current state of the art by one order of magnitude.

Abstract: Software Defined Networking (SDN) and Named Data Networking (NDN) are two topics which have received lots of attention in the networking research community in recent years. While both have emerged independently from each other we believe that their core features can be well aligned to each other. Hence combining both may hold potential benefits for network operators. In this paper we investigate the advantage of having a central SDN controller which is aware of the complete topology of an underlying NDN network. In our approach we use the controller for routing Interests for names unknown to the forwarding elements and to find alternative routes in case of link congestion. Another advantage of SDN is the ability to analyze and control the network on an application-layer component which communicates with the controller. This allows the development of application-aware networks that support the specific needs of the applications that use them. As an example use case we assumed a network whose main purpose is to disseminate multimedia content with Zipf-distributed popularity among users. Having an application layer which knows about content popularity statistics we improve the dissemination of multimedia content by instructing dedicated nodes in the network to prefetch content which is expected to become popular in their geographical region or autonomous system (AS) in the near future. The aim of this approach is to reduce the distance to potential consumers and reduce the load of the core network.

Abstract: Taking a photo with a digital camera or camera phone is a process triggered by a certain motivation. People want for instance to document the progress of a task, others want to preserve a moment of joy. In this contribution we present an openly available dataset with 1,309 photos along with annotations specifying the intentions of the photographers. This data set is the result of a large survey on Flickr and shall provide a common basis for joint research on user intentions in photo production. The survey data was validated using Amazon Mechanical Turk. Besides discussing the process of creating the data set we also present information of the structure and give statistics on the data set.

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: The emerging MPEG standard Dynamic Adaptive Streaming over HTTP (MPEG-DASH) is designed for media delivery over the top of existing infrastructures and enables smooth multimedia streaming towards heterogeneous devices including both wired and wireless environments. The MPEG-DASH standard was designed to work with HTTP-URLs but mandates neither the actual version nor which underlying protocols to be used. This paper will provide a detailed introduction into emerging protocols (HTTP/2.0 and beyond) to be used in the context of adaptive media streaming, specifically DASH.