Rate Control in Versatile Video Coding with Cosh Rate-Distortion Model

In this paper, we propose a rate control (RC) scheme for versatile video coding (VVC) to enhance coding performance. First, we propose a rate-distortion (R-D) model at the coding tree unit (CTU) level to describe the R-D relationship. Second, we adjust the quantization parameter (QP) and Lagrange multiplier at the coding unit (CU) level according to visual features to improve the rationality of local coding results. Finally, we propose a model parameter updating strategy to guarantee bitrate accuracy. The experimental results demonstrate that our RC method has better R-D performance with similar bitrate accuracy and better visual quality compared to the default RC strategy in VVC reference software VTM 10.2.