An Efficient Rate Control Algorithm for Intra Frame Coding in AVS3

The third generation Audio Video Coding Standard (AVS3) has been developed that improves coding performance significantly. However, the optimization research on rate control for AVS3 is not fully exploited. This paper presents a rate control method that is efficient for intra frame coding in AVS3. Specifically, at the frame-level, a Rate-SATD-QP (RSQ) model is derived based on the sum of absolute transformed difference (SATD) to calculate the quantization parameter (QP). Furthermore, at the coding tree uint (CTU) level, a feedback mechanism is developed to adjust QP for more fine-grained rate control. Experimental results demonstrate that, compared with the Fixed-QP algorithm in the AVS3 reference software (HPM 7.0), our scheme achieves 0.13% bitrate error on average with a 0.08% BD-rate gain in the Y component, meanwhile producing 2.19% and 2.53% BD-rate gains in the U and V components, respectively.