Scalable Coding of 360-degree Video for Streaming Adaptation at 5G Network Edges

The huge amount of data that is necessary to capture the full field-of-view (FoV) in omnidirectional video, i.e., 360°, imposes the use of highly efficient compressed formats as well as adaptive broadcast and streaming mechanisms, such as those foreseen for 5G networks. To cope with the demanding requirements of 360° video streaming over 5G networks, this work proposes a scalable 360° video coding architecture, by enabling adaptation through the Multi-Access Edge Computing (MEC) server in two different domains of the spherical visual content, namely spatial resolution and FoV. In the proposed architecture two-layers are encoded from the input 360° video content: (i) the base-layer (BL), encoding each 360° image as a whole, at a lower spatial resolution; (ii) the enhancement-layer (EL) encoding each spherical image as a set of multiple FoVs with higher spatial resolution. Such arrangement enables flexible stream adaptation for the smart decision algorithms to be implemented at the MEC server, enabling significant reduction of the overall bit rate through the radio interface. The simulation results show that the proposed scalable coding scheme allows a great deal of bit rate savings across the 5G network, achieving 36% of bit rate saving, on average, for a 90° FoV in comparison with conventional single-layer coding.