Comparison of HEVC-based OMAF-compliant 6K effective packings for viewport-dependent 360-degree video streaming

Omnidirectional MediA Format (OMAF), a recent standard for representation of 360° video content, supports only equirectangular projection (ERP) and cubemap projection (CMP) and their region-wise packing with a 4K decoding-capability constraint on the end-user devices. Streaming of 4K content allows only a limited viewport resolution, which is lower than the resolution of many current head-mounted displays (HMDs). Two 6K-effective multi-resolution packing schemes for ERP and CMP are recommended by the OMAF standard, which take full advantages of HMDs with quad HD resolution while sticking with 4K-decoding constraint. This paper studies and compares the performance of these two packings in the context of viewport-adaptive streaming using the High Efficiency Video Coding (HEVC) standard and Zonal-PSNR test methodology. Overall, the experimental results show that rate-distortion performance of both packings sequence wise mixed but similar in average.