International organisation for standardisation

Transform skipping (AHG19) ([e-mail]) Study the adequacy of different entropy coding tools (scans, contexts) with different transform skip modes Study transform skip mode flags signalling in the context of the RQT design Identify and discuss additional issues relating to transform skip mode Study throughput and complexity issues in the context of transform skipping	M. Mrak (chair), J. Sole, I.-K. Kim, J. Xu, H. Yu (vice chairs)
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Chroma format support (AHG20) ([e-mail]) Study aspects of the technical design and software that need modification to support non-4:2:0 chroma formats. Assist and advise in the work of removing implicit assumptions of 4:2:0 formatting from the WD and software (where feasible, without introducing technical design changes).	D. Flynn (chair), D. Hoang, K. McCann (vice chairs)	N
Reference picture buffering and list construction (AHG21) ([e-mail]) Study possible improvements to the reference picture list construction processes Examine the behaviour of unified lists with the JCTVC-F493 proposed default list construction processes and identify any robustness issues. Examine the merits of the list 0/1, combined and unified lists Discuss and identify solutions for support of weighted prediction methods Produce a single candidate WD text specification for picture buffer management based on JCTVC-F493 for review at the next meeting Produce software supporting picture marking including the following features: Flexible support for cyclic picture structures and temporal layering Decoder support to decode a subset of temporal layers Rudimentary error concealment for lost reference picture slices (frame copy of closest picture based on POC, set all MVs of lost reference picture to zero)	D. Flynn, R. Sjöberg (co-chairs), Y. Chen, T. K. Tan, W. Wan, Y. K. Wang (vice chairs)	N
Lossless coding (AHG22) ([e-mail]) Study and investigate lossless coding techniques. Consider complexity and efficiency tradeoffs. Identify appropriate intra and inter predictive techniques for lossless coding. Consider bit depth effects.	W. Gao (chair), K. Chono, J. Xu, M. Zhou (vice chairs)	N