Versatile Video Coding Based Quality Scalability With Joint Layer Reference

Scalability is an essential coding feature for adaptive video streaming applications, notably considering the growing heterogeneity of the transmission, display and consumption environments. Versatile video coding (VVC) is the emerging video coding standard, targeting offering higher compression efficiency regarding previous standards to further facilitate already available and novel video applications, notably at higher spatial resolutions. In this context, this letter proposes the first VVC-based quality scalability extension, targeting to offer higher compression efficiency than the native VVC quality scalability solution. The proposed Quality Scalable Versatile Video Coding (QS-VVC) solution is designed based on a layered coding approach with one base layer (BL) and one or more enhancement layers (EL). To achieve higher compression performance, a novel joint layer referencing approach is proposed where the base and enhancement layers decoded information are jointly exploited to create a new EL coding reference. Experimental results shown that the proposed QS-VVC codec outperforms the most relevant benchmarks, notably VVC-based simulcasting, native VVC quality scalability, and the previous Scalable High Efficiency Video Coding (SHVC) standard.