Intra block copy in Versatile Video Coding with Reference Sample Memory Reuse Screen contents such as online gaming streaming, remote desktop and WIFI display, become popular in current mainstream video applications. In versatile video coding (VVC), the most recent international video coding standard development, coding tools have been evaluated for optimizing screen content materials. Intra block copy (IBC) has shown its effectiveness in coding of computergenerated contents such as texts and graphics. Therefore, it has been previously included into the HEVC standard version 4, extensions for screen content coding (SCC). A constrained version of IBC mode has also been adopted in the VVC standard where the compensation range is limited within the current codingtree unit (CTU), assuming a 1CTU size of memory is allocated for storing IBCxe2x80x99s reference samples. In this paper, methods are proposed to efficiently utilize this reference sample memory for IBC mode such that effectively the search range for IBC mode can be increased without requiring more memory to store the reference samples. As a result, significant coding efficiency improvement over the traditional 1CTU search range setting can be achieved. One of the proposed memory reuse strategies is considered practical for implementation and therefore has been included in the VVC standard.

A Novel Partition Mode for Screen Content Video in AVS3 With the development of applications such as wireless displays and remote desktop, screen content coding (SCC) has been a topic of increasing interest. The stateoftheart partition modes in AVS3 restrict a parent coding unit (CU) to partition into no more than four subCUs in each partition process. To obtain more than four smaller subCUs, a parent CU needs to partition recursively. In this paper, to simplify the recursive partition processes and improve SCC efficiency, a novel partition mode which allows a parent CU to be partitioned into several predefined smaller subCUs with the same shape and size directly is proposed. We make some preexperiments to verify the validity of the proposed partition mode, and limit the application scope to four rectangular CU sizes based on the preexperimental results. As demonstrated in the experimental results, the proposed partition mode can obviously improve SCC efficiency.