Reinforcement Learning based ROI Bit Allocation for Gaming Video Coding in VVC

In this paper, we propose a reinforcement learning based region of interest (ROI) bit allocation method for gaming video coding in Versatile Video Coding (VVC). Most current ROI-based bit allocation methods rely on bit budgets based on frame-level empirical weight allocation. The restricted bit budgets influence the efficiency of ROI-based bit allocation and the stability of video quality. To address this issue, the bit allocation process of frame and ROI are combined and formulated as a Markov decision process (MDP). A deep reinforcement learning (RL) method is adopted to solve this problem and obtain the appropriate bits of frame and ROI. Our target is to improve the quality of ROI and reduce the frame-level quality fluctuation, whilst satisfying the bit budgets constraint. The RL-based ROI bit allocation method is implemented in the latest video coding standard and verified for gaming video coding. The experimental results demonstrate that the proposed method achieves a better quality of ROI while reducing the quality fluctuation compared to the reference methods.