Christian Timmerer

IEEE JSAC: Multimedia Economics for Future Networks: Theory, Methods, and Applications


Authors: Wen Ji, Zhu Li, H. Vincent Poor, Christian Timmerer, and Wenwu Zhu

Abstract: With the growing integration of telecommunication networks, Internet of Things (IoT), and 5G networks, there is a tremendous demand for multimedia services over heterogeneous networks. According to recent survey reports, mobile video traffic accounted for 60 percent of total mobile data traffic in 2016, and it will reach up to 78 percent by the end of 2021. Users’ daily lives are inundated with multimedia services, such as online video streaming (e.g., YouTube and Netflix), social networks (e.g., Facebook, Instagram, and Twitter), IoT and machine generated video (e.g, surveillance cameras), and multimedia service providers (e.g., Over-the-Top (OTT) services). Multimedia data is thus becoming the dominant traffic in the near future for both wired and wireless networks.

W. Ji, Z. Li, H. V. Poor, C. Timmerer and W. Zhu, “Guest Editorial Multimedia Economics for Future Networks: Theory, Methods, and Applications,” in IEEE Journal on Selected Areas in Communications, vol. 37, no. 7, pp. 1473-1477, July 2019.
doi: 10.1109/JSAC.2019.2918962


Christian Timmerer

ACM NOSSDAV’19 paper on Bandwidth Prediction in Low-Latency Chunked Streaming received Excellence in DASH award at ACM MMSys 2019


Authors: Abdelhak Bentaleb (National University of Singapore), Christian Timmerer (Alpen-Adria Universität & Bitmovin Inc,), Ali C. Begen(Ozyegin University), and Roger Zimmermann (National University of Singapore)

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 band- width 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.


– Slides/PDF:

– DASH Industry Forum Excellence in DASH Award at ACM MMSys 2019:

Philipp Moll and Sabrina Kletz presented their Demo on “Alternative inputs for games and AR/VR applications” @ MMSys 2019 in Amherst


Paper Title: Alternative inputs for games and AR/VR applications: deep headbanging on the web

Abstract: In multimedia research, scientific progress is often slowed downby high demands on hard- and software. However, hardware con-tinuously improves and today’s hardware got powerful enoughto meet the performance demands of complex 3D and deep learn-ing applications. With this demo, we demonstrate that utilizingdeep learning and 3D modeling is not a major barrier anymorewhen building prototypes for showcasing research projects. Ourweb-based game, called “HeadbangZ”, showcases a novel gesture-based input methodology realized through deeply learned poseestimation and user interaction in a 3D environment. Since gesture-based inputs increase the immersion in virtual environments, weassume this input methodology to be especially useful for AR/VRapplications and games. Furthermore, we demonstrate that rapidprototyping of applications using novel technologies, such as deeplearning, is even possible within 48 hours by developing a workingdemo within this time frame. Finally, we provide insights into whatwe learned during the development of HeadbangZ to encourageother researchers to make use of novel technologies. In referenceto Stephen Harper’s quote “Having hit a wall, the next logical stepis not to bang our heads against it.”, we hope that the presentationof HeadbangZ encourages researchers to bang their heads rhythmi-cally to rock music instead of angrily against a virtual wall createdby hard- and software limitations.

Authors: Philipp Moll, Andreas Leibetseder, Sabrina Kletz, Mathias Lux, Bernd Münzer (Institute of Information Technology, Alpen-Adria-Universität Klagenfurt)

More information on the paper can be found on:

A glimpse into ARTICONF meeting @Stavanger, Norway.

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Prof. Radu Prodan coordinated EU H2020 Project ARTICONF team met at Stavanger and held technical cum plenary discussions between June 4th to June 7th 2019 with a goal to present some exciting development towards next generation social media.

Articonf meeting at Stavanger 2019

Articonf meeting at Stavanger 2019

QoMEX’19: Tile-based Streaming of 8K Omnidirectional Video: Subjective and Objective QoE Evaluation


Autor: 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.

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

Link: QoMEX_19__Tile_based_ODV_Streaming_QoE_camready.pdf