226 research outputs found
Dissecting the performance of VR video streaming through the VR-EXP experimentation platform
To cope with the massive bandwidth demands of Virtual Reality (VR) video streaming, both the scientific community and the industry have been proposing optimization techniques such as viewport-aware streaming and tile-based adaptive bitrate heuristics. As most of the VR video traffic is expected to be delivered through mobile networks, a major problem arises: both the network performance and VR video optimization techniques have the potential to influence the video playout performance and the Quality of Experience (QoE). However, the interplay between them is neither trivial nor has it been properly investigated. To bridge this gap, in this article, we introduce VR-EXP, an open-source platform for carrying out VR video streaming performance evaluation. Furthermore, we consolidate a set of relevant VR video streaming techniques and evaluate them under variable network conditions, contributing to an in-depth understanding of what to expect when different combinations are employed. To the best of our knowledge, this is the first work to propose a systematic approach, accompanied by a software toolkit, which allows one to compare different optimization techniques under the same circumstances. Extensive evaluations carried out using realistic datasets demonstrate that VR-EXP is instrumental in providing valuable insights regarding the interplay between network performance and VR video streaming optimization techniques
Video Quality Evaluation for Tile-Based Spatial Adaptation
The demand for very high-resolution video
content in entertainment services (4K, 8K, panoramic,
360 VR) puts an increasing load on the distribution
network. In order to reduce the network usage in
existing delivery infrastructure for such services while
keeping a good quality of experience, dynamic spatial
video adaptation at the client side is seen as a key
feature, and is actively investigated by academics and
industrials. However, the impact of spatial adaptation
on quality perception is not clear. In this paper, we propose
a methodology for the evaluation of such adapted
content, conduct a series of perceived quality measurements
and discuss results showing potential benefits
and drawbacks of the technique. Based on our results,
we also propose a signaling mechanism in MPEGDASH
to assist the client in its spatial adaptation log
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