id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
796	Bug in down-sampled collocated luma samples derivation in CCLM	lphamvan		"'''- In the  current spec, the first row and first column of luma reference block is not assigned in YUV444.'''

3.	The down-sampled collocated luma samples pDsY[ x ][ y ] with x = 0..nTbW − 1,  y = 0..nTbH − 1 are derived as follows:
–	If both SubWidthC and SubHeightC are equal to 1, the following applies:
–	pDsY[ x ][ y ] with x = [[span(style=color: #FF0000, 1)]]..nTbW − 1, y = [[span(style=color: #FF0000, 1)]]..nTbH − 1 is derived as follows:
pDstY[ x ][ y ] = pY[ x ][ y ]				(355)

It is suggested to fix as:
pDsY[ x ][ y ] with x = ~~[[span(style=color: #FF0000, 1)]]~~0..nTbW − 1, y = ~~[[span(style=color: #FF0000, 1)]]~~0..nTbH − 1 is derived as follows:
pDstY[ x ][ y ] = pY[ x ][ y ]				(355)

'''The index in (382) and (384) is incorrect.''' 

pSelDsY[ idx ] = ( F3[ 1 ][ 0 ] * pY[ −1 ][ [[span(style=color: #FF0000, − 1 − SubHeightC)]] ] + ...

In YUV420, − 1 − SubHeightC = -1 - 2 = -3. However, the line -3 of pSelDsY is never assigned.

It is suggested to fix this bug also.
"	defect	closed	minor		spec	VVC D8 vB	fixed		ksuehring bbross XiangLi fbossen jvet@…