Multimedia Communication

Christian Timmerer

ACM NOSSDAV’19 paper on “Bandwidth Prediction in Low-Latency Chunked Streaming” accepted

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Authors: Abdelhak Bentaleb, Christian Timmerer, Ali C. Begen, and Roger Zimmermann

Abstract: HTTP adaptive streaming (HAS) with chunked transfer encoding can be used to reduce latency without sacrificing the coding ef- ficiency. While this allows a media segment to be generated and delivered at the same time, it also causes grossly inaccurate bandwidth measurements, leading to incorrect bitrate selections. To overcome this effect, we design a novel Adaptive bitrate scheme for Chunked Transfer Encoding (ACTE) that leverages the unique nature of chunk downloads. It uses a sliding window to accurately measure the available bandwidth and an online linear adaptive filter to predict the available bandwidth into the future. Results show that ACTE achieves 96% measurement accuracy, which translates to a 64% reduction in stalls and a 27% increase in video quality.

Acknowledgment: This research has been supported in part by the Singapore Ministry of Education Academic Research Fund Tier 1 under MOE’s official grant number T1 251RES1820 and the Austrian Research Promotion Agency (FFG) under the Next Generation Video Streaming project “PROMETHEUS”.

Keywords: HAS; ABR; DASH; CMAF; low-latency; HTTP chunked transfer encoding; bandwidth measurement and prediction; RLS.

Link: http://nossdav.org/2019/

Article “Active Online Learning for Social Media Analysis to Support Crisis Management” published in the “early access” area of the prestigious journal IEEE Transactions on Knowledge and Data Engineering

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The paper “Active Online Learning for Social Media Analysis to Support Crisis Management” was published as an “early access” article in the journal IEEE Transactions on Knowledge and Data Engineering (Q1 in ScimagoJR). The research leading to these results received funding from the EU FP7 Programme under grant agreement no. 261817 and was performed in collaboration with Bournemouth University, UK.

Authors: Daniela Pohl (AAU Klagenfurt, Inst. of Information Technology), Abdelhamid Bouchachia (Bournemouth University, Dept. of Computing, UK), Hermann Hellwagner (AAU Klagenfurt, Inst. of Information Technology)

Abstract: People use social media (SM) to describe and discuss different situations they are involved in, like crises. It is therefore worthwhile to exploit SM contents to support crisis management, in particular by revealing useful and unknown information about the crises in real-time. Read more

Christian Timmerer

QoMEX’19 paper on “Tile-based Streaming of 8K Omnidirectional Video: Subjective and Objective QoE Evaluation” accepted

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Authors: Raimund Schatz (AIT Austrian Institute of Technology), Anatoliy Zabrovskiy (Alpen-Adria Universität Klagenfurt), Christian Timmerer(Alpen-Adria Universität Klagenfurt, Bitmovin Inc.)
Abstract: Omnidirectional video (ODV) streaming applications are becoming increasingly popular. They enable a highly immersive experience as the user can freely choose her/his field of view within the 360-degree environment. Current deployments are fairly simple but viewport-agnostic which inevitably results in high storage/bandwidth requirements and low Quality of Experience (QoE). A promising solution is referred to as tile- based streaming which allows to have higher quality within the user’s viewport while quality outside the user’s viewport could be lower. However, empirical QoE assessment studies in this domain are still rare. Thus, this paper investigates the impact of different tile-based streaming approaches and configurations on the QoE of ODV. We present the results of a lab-based subjective evaluation in which participants evaluated 8K omnidirectional video QoE as influenced by different (i) tile-based streaming approaches (full vs. partial delivery), (ii) content types (static vs. moving camera), and (iii) tile encoding quality levels determined by different quantization parameters. Our experimental setup is characterized by high reproducibility since relevant media delivery aspects (including the user’s head movements and dynamic tile quality adaptation) are already rendered into the respective processed video sequences. Additionally, we performed a complementary objective evaluation of the different test sequences focusing on bandwidth efficiency and objective quality metrics. The results are presented in this paper and discussed in detail which confirm that tile-based streaming of ODV improves visual quality while reducing bandwidth requirements.

Index Terms: Omnidirectional Video, Tile-based Streaming, Subjective Testing, Objective Metrics, Quality of Experience

Acknowledgment: This work was supported in part by the Austrian Research Promotion Agency (FFG) under the Next Generation Video Streaming project “PROMETHEUS”.

Link: https://www.qomex2019.de/

Hermann Hellwagner appointed Member of Scientific Board of Christian Doppler Research Association

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Prof. Hellwagner, head of ITEC, has been appointed Member of the Scientific Board of  the CD Research Association for the period of 2019. The Christian Doppler Research Association promotes cooperation between science and business, whereas the Scientific Board and its members serve as scientific advisory committee to ensure the quality of research. The CDG Scientific Board consists of up to 45 members from Academia and Business. Prof. Hellwagner’s appointment is effective from January, 2019.

Christian Doppler Research Association approves ATHENA project proposal

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ATHENA stands for Adaptive Streaming over HTTP and Emerging Networked Multimedia Services and has been jointly proposed by the Institute of Information Technology (ITEC; https://itec.aau.at) at Alpen-Adria-Universität Klagenfurt (AAU) and Bitmovin GmbH (https://bitmovin.com) to address current and future research and deployment challenges of HTTP adaptive steaming (HAS) and emerging streaming methods. Read more

ITEC researchers presenting at 25th IEEE International Conference on Image Processing (ICIP) in Athens, Greece on October 7-10, 2018

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The 25th IEEE International Conference on Image Processing (ICIP; https://2018.ieeeicip.org/) will be held in Athens, Greece on October 7-10, 2018. ITEC researcher Anatoliy Zabrovskiy will present “A Practical Evaluation of Video Codecs for Large-Scale HTTP Adaptive Streaming Services” within the special session on “Video Coding at Scale”. The abstract is as follows: The number of bandwidth-hungry applications and services is constantly growing. HTTP adaptive streaming of audiovisual content accounts for the majority of today’s internet traffic. Although the internet bandwidth increases also constantly, audio-visual compression technology is inevitable and we are currently facing the challenge to be confronted with multiple video codecs. This paper provides a practical evaluation of state of the art video codecs (i. e., AV1, AVC/libx264, HEVC/libx265, VP9/Iibvpx-vp9) for large-scale HTTP adaptive streaming services. In anticipation of the results, AV1 shows promising performance compared to established video codecs. Additionally, AV1 is intended to be royalty free making it worthwhile to be considered for large scale HTTP adaptive streaming services. Read more

Hermann Hellwagner @ IKT-Konvent 2018

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Hermann Hellwagner actively participated in the “IKT-Konvent 2018” in Vienna on September 17, 2018. The event was to boost Austrian R&D, commercial, and educational activities toward the fully digital and connected world. As one of the panel members, Hellwagner contributed to the session “5G Applications” which discussed potential applications and benefits of future 5G networks, how to prototype and introduce 5G infrastructure and applications, and which cooperations among industry, academia, and government are required to perform 5G projects and become a frontrunner in the 5G area.

Christian Timmerer

A Survey on Bitrate Adaptation Schemes for Streaming Media over HTTP accepted in IEEE Communications Surveys & Tutorial

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ITEC researcher Christian Timmerer co-authored a survey on bitrate adaptation schemes for streaming media over HTTP which has been accepted in IEEE Communications Surveys & Tutorial and will be available as open access. This journal covers all aspects of the communication field with an impact factor of 20.23 according to IEEEExplore.

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Philipp Moll

Philipp Moll @ UCLA

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Philipp Moll is currently visiting his Mentor Jeff Burke at UCLA in Los Angeles. During the stay at UCLA, he is working together with the researchers of the _Center for Research in Engineering, Media, and Performance_ (REMAP) and with Lixia Zhang’s group of the _Internet Research Lab_ (IRL).

The stay is enabled by the Young Scientists Mentoring Program of AAU, where Philipp Moll is taking part and mentored by Prof. Jeff Burke.

Christian Timmerer

Christian Timmerer to give a tutorial at IEEE International Conference on Multimedia and Expo (ICME) 2018 in San Diego, CA, USA

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The IEEE International Conference on Multimedia and Expo (ICME) is sponsored by four IEEE societies since 2000 and provides a forum to discuss latest developments in the domain of multimedia technologies related to circuits and systems, communications, computer, and signal processing communities. Dr. Timmerer will give a full-day tutorial on “Delivering Traditional and Omnidirectional Media” together with renowned experts Ali C. Begen and Liangping Ma. Furthermore, he will participate in IEEE business meetings, notably board meeting of IEEE Transactions on Multimedia, IEEE Multimedia Communications Technical Committee (MMTC), and IEEE Technical Committee on Multimedia Computing (TCMC).

Links:

– http://www.icme2018.org/

– https://multimediacommunication.blogspot.com/2018/01/delivering-traditional-and.html