An Adaptive Determination Method for Gop-size and Qp Offset in Versatile Video Coding

In the latest and most advanced video coding standard, Versatile Video Coding (VVC), the configuration parameters of the size of Groups of Pictures (GOP) and the offset of Quantization Parameter (QP) in a GOP significantly impact the compression efficiency. However, typical VVC encoder implementations assume fixed GOP-size and QP offset for encoding video sequences, which is inefficient for video sequences with diverse content and cannot guarantee optimal rate-distortion performance for diverse video sequences. In this paper, we propose a simple but effective adaptive determination method for GOP-size and QP offset in VVC. Specifically, the GOPsize and the QP offset are adaptively determined according to the temporal characteristics of video sequences, and such temporal characteristics are calculated based on existing motion vectors in the encoded information. Experimental results have demonstrated that, with a negligible increase in encoding time, the proposed method can reduce Bjøntegaard delta bit-rate (BDBR) by 5.53% on average compared with the original VVC.