Look-Ahead Prediction Based Coding Unit Size Pruning for VVC Intra Coding

In the emerging video coding standard, Versatile Video Coding (VVC), a quadtree with nested multi-type tree (MTT) using binary and ternary tree structure was proposed. MTT brings significant coding efficiency but increases the encoding complexity. In this paper, a look-ahead prediction based coding unit size pruning algorithm is proposed to cut down redundant MTT partitions. The proposed scheme aims to identify the unnecessary partition direction in advance and consists of two steps, i.e. SATD-based mode decision (SMD) for possible blocks and refined cost derivation based on rate-distortion optimization. Experimental results show that the proposed method can save 41% encoder time with only 0.84% increase in bit rate on average.