A Method for Rate-Distortion-Complexity Optimization in Versatile Video Coding Standard

The most recent video coding standard, named Versatile Video Coding (VVC), greatly improved the compression rate compared to its predecessor, High Efficiency Video Coding (HEVC) using some new coding tools. Though these new option provide appreciable coding gain, its computational complexity is relatively high since the performance of these coding tools need to be evaluated for each Coding Tree Units (CTU) through the Rate-Distortion Optimization (RDO) process. To address this issue, in this paper, first, the effectiveness of the coding tools in various parts of the frame, such as the borderline and central CTU, is investigated. The results of this study show that the coding efficiency of some of these coding tools is much higher for the borderline CTUs due to their specific features. Hence, these coding tools would be only considered enable for the borderline CTUs in rate-distortion process to decrease the computational complexity, without affecting the coding gain considerably. Simulation results show that using this method, the compression efficiency decreased only by 0.64% in average, but the computational complexity is reduced considerably, by 28.31%, in average.