HTTP Adaptive Streaming – Where is it Heading?

Speaker: Prof. Hermann Hellwagner

🗓 3:00 P.M.-3:45 P.M. (Taiwan), 8:00 A.M.-8:45 A.M. (Austria), 9:00 A.M.-9:45 A.M. (Finland)

Video traffic on the Internet is constantly growing; networked multimedia applications consume a predominant share of the available Internet bandwidth. A major technical breakthrough and enabler in multimedia systems research and of industrial networked multimedia services certainly was the HTTP Adaptive Streaming (HAS) technique. This resulted in the standardization of MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH) which, together with HTTP Live Streaming (HLS) by Apple Inc., is widely used for multimedia delivery in today’s networks.

Existing challenges in multimedia systems research deal with the trade-off between (i) the ever-increasing content complexity, (ii) various requirements with respect to time (most importantly, latency), and (iii) quality of experience (QoE). Optimizing towards one aspect usually negatively impacts at least one of the other two aspects if not both.

This situation sets the stage for our research work in the ATHENA Christian Doppler (CD) Laboratory (Adaptive Streaming over HTTP and Emerging Networked Multimedia Services; https://athena.itec.aau.at/), jointly funded by public sources and industry.

In this talk, we will present selected novel approaches and research results of the first year of the ATHENA CD Lab’s operation. We will highlight HAS-related research on: (i) multimedia content provisioning (machine learning for video encoding); (ii) multimedia content delivery (support of edge processing and virtualized network functions for video networking); (iii) multimedia content consumption and end-to-end aspects (player-triggered segment retransmissions to improve video playout quality); and (iv) novel QoE investigations (adaptive point cloud streaming). We will also put the work into the context of the international multimedia systems research.

Real-time Communications - Opportunities and Challenges

Speaker: Dr. Chih-Fan Hsu

🗓 3:45 P.M.-4:00 P.M. (Taiwan), 8:45 A.M.-9:00 A.M. (Austria), 9:45 A.M.-10:00 A.M. (Finland)

During the outbreak of epidemic diseases, the importance of real-time communication (RTC) systems dramatically increases. People use RTC systems for communication, attending online courses, presentations, and sharing videos with others. On the consumer side, how to choose an appropriate system to satisfy different network conditions, applications, and scenarios is an open question; On the developer side, how to maintain the user experience of end-users in any circumstance becomes extremely important. To answering these critical end questions, finding and comparing the advantages and disadvantages of current systems leads the ways. However, conducting a fair and general evaluation for all current commercial products is challenging because they are well packaged and secured. In this talk, the lecturer will introduce a method to evaluate the well-known commercial products, reveal their advantages and disadvantages. Then, highlight the design consideration for the future development of RTC systems

Light Field Image Compression with Random Access

Speaker: Mr. Hadi Amirpour

🗓 4:00 P.M.-4:15 P.M. (Taiwan), 9:00 A.M.-9:15 A.M. (Austria), 10:00 A.M.-10:15 A.M. (Finland)

Light field imaging enables some post-processing functions such as depth estimation, refocusing, and changing the perspective angle of a view. Due to multiple view representations of light field images, they contain a huge amount of data, which makes compression inevitable. In addition to coding efficiency, light field compression should also take into account some important functionalities such as random access, scalability, and uniform quality distribution. Conventional light field compression methods usually make light field image views highly dependent on each other to increase encoding efficiency by using inter-view prediction. However, navigating between different views may require the decoding of a large number of views, which can have a significant impact on decoding delay, bandwidth requirements and processing power. To avoid these problems, random access to the image views should be considered in light field image encoding schemes. In this talk, efficient light field image compression methods are presented which take into account random access in addition to the encoding efficiency.

Latency Challenges in Cloud-accelerated XR and Gaming

Speaker: Dr. Teemu Kämäräinen

🗓 4:15 P.M.-5:00 P.M. (Taiwan), 9:15 A.M.-10:00 A.M. (Austria), 10:15 A.M.-11:00 A.M. (Finland)

Mobility for high-quality gaming and XR applications with real-time rendered graphics is challenging to achieve as the processing power of mobile devices is an order of magnitude weaker than PC setups. This problem can be overcome by offloading the graphics rendering to remote servers in the cloud. The main challenge in the remote rendering of graphics is the added latency. Games and XR applications often have a high rate of user interaction and the effect of the interaction needs to be visible for the user as soon as possible to ensure a good quality of experience. Edge computing and 5G mobile networks can only mitigate the problem as the remote rendering and transport of graphics add inherent delay to the pipeline. In this talk, we will present various solutions to overcome this challenge and also discuss future research directions with the ultimate goal to completely hide the latency so that the user cannot perceive the difference between a locally and remotely executed application.