Complexity assessment of the intra prediction in Versatile Video Coding

The Versatile Video Coding (VVC) was finalized in July 2020 by the Joint Video Experts Team (JVET). During the standardization process, many coding techniques were investigated in order to provide superior coding efficiency with high level of versatility over the High Efficiency Video Coding (HEVC). Indeed, VVC achieved about 40% of bitrate saving compared to its predecessor for the same objective visual quality. However, its encoding complexity has considerably increased due to the exhaustive Rate-Distortion (RD) search. In this paper, a complexity assessment of the intra mode decision of VVC is presented. Experimental results reveal that the intra coding tools and the steps of intra mode decision have various degrees of complexity. Thus, opening up several complexity reduction opportunities, that yield up to 43% of complexity reduction. Also, VVC tends usually to select the 6 Most Probable Modes (MPMs). However, this selection may depend on the used intra coding tool and video texture characteristics. These conclusions give clear openings to accelerate the intra mode decision.