Viewport-adaptive navigable 360-degree video delivery

Abstract

The delivery and display of 360-degree videos on Head-Mounted Displays (HMDs) presents many technical challenges. 360-degree videos are ultra high resolution spherical videos, which contain an omnidirectional view of the scene. However only a portion of this scene is displayed on the HMD. Moreover, HMD need to respond in 10 ms to head movements, which prevents the server to send only the displayed video part based on client feedback. To reduce the bandwidth waste, while still providing an immersive experience, a viewport-adaptive 360degree video streaming system is proposed. The server prepares multiple video representations, which differ not only by their bit-rate, but also by the qualities of different scene regions. The client chooses a representation for the next segment such that its bit-rate fits the available throughput and a full quality region matches its viewing. We investigate the impact of various spherical-to-plane projections and quality arrangements on the video quality displayed to the user, showing that the cube map layout offers the best quality for the given bit-rate budget. An evaluation with a dataset of users navigating 360-degree videos demonstrates that segments need to be short enough to enable frequent view switches.

QoE Management of Multimedia Streaming Services in Future Networks: A Tutorial and Survey

“…Video resolution and network budget [287], screen size [289]; viewport quality and the sensitivity to head movements [299] No High/Medium deployment complexity and the most impacting metrics on QoE in Table VI. The discussion above clearly points toward a shift towards the adoption of SDN and NFV paradigms for QoE management and orchestration of network resources in future networks.…”

“…Thus, 360 • video applications, for example, could integrate additional 360 • sensory media content (e.g., olfactory, haptic or thermoceptics media objects) that could eventually enable an even better quality of user experience [324]. However, the new 360 • mulsemedia services would come at the cost of more bandwidth than the conventional applications [298] and stringent delay requirements [299]. Yuan et al introduce QoE of mulsemedia services where users can inform the mulsemedia server about both user preferences and network delivery conditions [294].…”

Network Support for AR/VR and Immersive Video Application: A Survey

“…Moreover, this scheme reduces the storage requirements significantly and improves in-network cache performance. (Corbillon et al, 2017c) targets at the problem of bandwidth waste: the Field of View (or viewport) is only a fraction of what is downloaded, which is an omnidirectional view of the scene. To prevent simulator sickness and to provide good Quality of Experience, the vendors of HMDs recommend that the enabling multimedia systems react to head movements as fast as the HMD refresh rate.…”

A Study on Quality Metrics for 360 Video Communications

“…Note that all model parameters including a, b, c, d, α, β, γ and p in Eqs. (7), (8), and (12) are obtained by curve-fitting using the data in Figs. 3, 4, and 5.…”

“…Most of 360 video related studies focus on investigating some aspects of video quality [4]- [6] in VR environment such as the presence, usability, and cybersickness. Some recent studies consider quality optimization for 360 video delivery [7], [8]. However, a good quality metric for 360 videos is still an open issue.…”