High quality omnidirectional video requires ultra high resolution formats encoded with very high bit rates to guarantee acceptable QoE in video delivery services. Since in general the full FoV, i.e., 360º, is not required at once by users, rather than agnostic encoding of the whole 360º video, this work proposes a flexible coding approach where the full FoV is mapped into video frames and efficiently encoded using intra-FoV prediction. By avoiding inter-FoV prediction, the proposed approach enables independent decoding of one or more FoVs extracted from a single compressed stream containing the full FoV video.
To achieve improved quality in those FoVs which attract more visual attention, non-uniform coding is proposed for the new Versatile Video Coding standard (VVC), using perceptually-driven quantisation for each FoV. This strategy, makes use of visual attention maps to decrease the overall bit rate without compromising the quality of the most relevant regions.
The simulation results show that the proposed coding mechanism achieves consistent quality gains in the relevant FoV without significant losses in the remaining ones. In comparison with the reference VVC, the proposed method is able to achieve average quality gains up to 1.56 dB and to efficiently adapt the coding parameters to the visual attention information.