Two-Stage Fast Multiple Transform Selection Algorithm for VVC Intra Coding

Abstract

Recently, the Joint Video Exploration Team (JVET) has established the latest video coding standard, Versatile Video Coding (VVC). The VVC adopts the Multiple Transform Selection (MTS) as a supplement to the primary transform, where DST7 and DCT8 are included as the optional transform kernels. Though MTS provides appreciable coding gain, its computational complexity is relatively high since several transforms need to be evaluated through the Rate Distortion Optimization (RDO) process. To address this issue, we propose a novel fast two-stage algorithm that utilizes the spacial coding statistics and the primary transform information to early terminate the RDO process of MTS. Experimental results show that by employing this fast MTS method inside VVC, one can achieve up to 23% time reduction with only 0.16% Bjontegaard Delta bitrate (BD-rate) increase.