Adeel Abbas

Performance comparison of AV1, HEVC, and JVET video codecs on 360 (spherical) video

This paper compares the coding efficiency performance on 360 videos, of three software codecs: (a) AV1 video codec from the Alliance for Open Media (AOM); (b) the HEVC Reference Software HM; and (c) the JVET JEM Reference SW. Note that 360 video is especially challenging content, in that one codes full res globally, but typically looks locally (in a viewport), which magnifies errors. These are tested in two different projection formats ERP and RSP, to check consistency. Performance is tabulated for 1-pass encoding on two fronts: (1) objective performance based on end-to-end (E2E) metrics such as SPSNR-NN, and WS-PSNR, currently developed in the JVET committee; and (2) informal subjective assessment of static viewports. Constant quality encoding is performed with all the three codecs for an unbiased comparison of the core coding tools. Our general conclusion is that under constant quality coding, AV1 underperforms HEVC, which underperforms JVET. We also test with rate control, where AV1 currently underperforms the open source X265 HEVC codec. Objective and visual evidence is provided.

A novel projection for omni-directional video

Omnidirectional video coding typically involves mapping spherical image data onto a two-dimensional plane by means of a projection format. In this paper, we introduce and share results on a relatively new projection format called Rotated Sphere Projection (RSP). RSP uses two symmetric and perfectly continuous segments to represent sphere. It has a simple 3:2 aspect ratio, close proximity to sphere and a very simple mathematical representation that is same as Equirectangular Projection. Test results using JVET’s common testing conditions are also presented.