id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
154	Availability check for CPR/IBC chroma CU reference block is missing	axink		"When dual-tree is used, the reference block for a chroma CU coded in CPR/IBC mode should be already reconstructed. This is not always guaranteed as chroma blocks are coded separately from luma. Availability check is necessary in this case but missed in the current spec text. A possible fix is provided as follows:
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–	The derivation process for chroma motion vectors in clause 8.4.2.13 is invoked with mvL0[ xSbIdx ][ ySbIdx ] and refIdxL0 as inputs, and mvCL0[ xSbIdx ][ ySbIdx ] as output.
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–	It is a requirement of bitstream conformance that the chroma motion vector mvCL0 shall obey the following constraints:
–	When the derivation process for block availability as specified in clause 6.4.X [Ed. (BB): Neighbouring blocks availability checking process tbd] is invoked with the current chroma location ( xCurr, yCurr ) set equal to ( xCb / SubWidthC, yCb / SubHeightC ) and the neighbouring chroma location ( xCb / SubWidthC + ( mvCL0[ xSbIdx ][ ySbIdx ][ 0 ] >> 5 ), yCb / SubHeightC + ( mvCL0[ xSbIdx ][ ySbIdx ][ 1 ] >> 5 ) ) as inputs, and the output shall be equal to TRUE.
–	When the derivation process for block availability as specified in clause 6.4.X [Ed. (BB): Neighbouring blocks availability checking process tbd] is invoked with the current chroma location ( xCurr, yCurr ) set equal to ( xCb / SubWidthC, yCb / SubHeightC ) and the neighbouring chroma location ( xCb / SubWidthC + ( mvCL0[ xSbIdx ][ ySbIdx ][ 0 ] >> 5 ) + cbWidth / SubWidthC − 1, yCb / SubHeightC + ( mvCL0[ xSbIdx ][ ySbIdx ][ 1 ] >> 5 ) + cbHeight / SubHeightC − 1 ) as inputs, and the output shall be equal to TRUE.
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–	One or both of the following conditions shall be true:
–	( mvCL0[ xSbIdx ][ ySbIdx ][ 0 ] >> 5 ) + xSbIdx * 2 + 2 is less than or equal to 0.
–	( mvCL0[ xSbIdx ][ ySbIdx ][ 1 ] >> 5 ) + ySbIdx * 2 + 2 is less than or equal to 0.
"	defect	closed	major	VVC D4 v1	spec	VVC D3 v9	fixed		ksuehring bbross XiangLi fbossen jvet@…