论文标题
基于复合Cauchy分布的多功能视频编码的高效率控制
High Efficiency Rate Control for Versatile Video Coding Based on Composite Cauchy Distribution
论文作者
论文摘要
在这项工作中，我们提出了一种基于其独特的速度延伸特性的多功能视频编码（VVC）标准的新型速率控制算法。通过使用复合库奇分布来建模转换系数，与传统分布相比，精确度更高。基于转换系数建模，理论上得出的R-Q和D-Q模型已被证明在表征具有不同内容的序列的RD特征方面提供了更高的精度，并将其纳入速率控制过程中。此外，为了建立一种自适应位分配方案，不同级别帧之间的依赖性是由描述参考和编码帧之间关系的依赖性因素建模的。鉴于派生的R-Q和D-Q关系以及依赖关系因子，为最佳位分配而开发了自适应位分配方案。我们在VVC测试模型（VTM）3.0上实施了建议的算法。实验表明，由于与默认速率控制算法相比，由于适当的位分配，对于低延迟配置，提出的算法可以实现1.03％的BD速率节省，而与固定QP方案相比，算法可以节省2.96％的BD率。此外，在随机访问配置下还观察到了1.29％的BD率节省和更高的控制精度。
In this work, we propose a novel rate control algorithm for Versatile Video Coding (VVC) standard based on its distinct rate-distortion characteristics. By modelling the transform coefficients with the composite Cauchy distribution, higher accuracy compared with traditional distributions has been achieved. Based on the transform coefficient modelling, the theoretically derived R-Q and D-Q models which have been shown to deliver higher accuracy in characterizing RD characteristics for sequences with different content are incorporated into the rate control process. Furthermore, to establish an adaptive bit allocation scheme, the dependency between different levels of frames is modelled by a dependency factor to describe relationship between the reference and to-be-coded frames. Given the derived R-Q and D-Q relationships, as well as the dependency factor, an adaptive bit allocation scheme is developed for optimal bits allocation. We implement the proposed algorithm on VVC Test Model (VTM) 3.0. Experiments show that due to proper bit allocation, for low delay configuration the proposed algorithm can achieve 1.03% BD-Rate saving compared with the default rate control algorithm and 2.96% BD-Rate saving compared with fixed QP scheme. Moreover, 1.29% BD-Rate saving and higher control accuracy have also been observed under the random access configuration.
