PhD defense of Mariem BEN YAHIA on May 10th, 2019

The defense of PhD thesis of Mariem Ben Yahia will be held on May 10th at  14:00 at IMT Atlantique, Rennes Campus , Petit Amphi. The thesis is entitled “Low Latency Video Streaming Solutions based on HTTP/2”. It was made in the framework of a CIFRE thesis with Orange Labs (Lannion).

Adaptive video streaming techniques encode the content at different levels of quality and split it into temporal segments. Before downloading a segment, the client runs an adaptation algorithm to determine the best level of quality to consider that matches the network resources. Besides, in the case of immersive video streaming this adaptation mechanism should also consider the head movement of a user watching the 360° video to maximize the quality of the viewed portion of the sphere. However, this adaptation may suffer from errors impacting negatively the end user’s quality of experience. In this case, an HTTP/1 client must wait for the download of the next segment to choose a suitable quality. In this thesis, we propose to use the HTTP/2 protocol instead to address this problem. First, we focus on the live streaming service. We design a strategy to discard video frames when the bandwidth is very variable in order to avoid the rebuffering events and the accumulation of delays. The customer requests each video frame in an HTTP/2 stream which allows to control the delivery of frames by leveraging the HTTP/2 features at the level of the dedicated stream. Second, we use the priority and reset stream features of HTTP/2 to optimize the immersive video streaming service. We propose a strategy to benefit from the improvement overtime of the user’s head movements prediction. The results show that HTTP/2 allows to optimize the use of network resources and to adapt the video delivery to the latencies required by each service.