id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
809	Issue with derivation of maxFilterLengthPs on coding subblock boundaries	emora		"In section 8.8.3.4, maxFilterLengthPs[x][y] is modified if left neighbor (vertical edge) or above neighbor (horizontal edge) is affine or in sub-block coding mode as per equations (8-1028) and (8-1040). The condition that enables this modification is written as follows, for example for vertical edge: ""When inter_affine_flag[ xCb − 1 ][ yCb ] is equal to 1 or merge_subblock_flag[ xCb − 1 ][ yCb ] is equal to 1, the following applies ...""

It seems to me that this is incorrect and should be ""inter_affine_flag[ xCb − 1 ][ yCb + y ]"" and ""merge_subblock_flag[ xCb − 1 ][ yCb + y ]"" because a block can have multiple (and smaller in height) left neighboring blocks along side its vertical edge, and not necessarily all are coded in affine/sub-block mode.

Same can be said for horizontal edge. Change would be: ""inter_affine_flag[ xCb + x ][ yCb − 1 ]"" and ""merge_subblock_flag[ xCb + x ][ yCb − 1 ]""

VTM software supports currently the proposed modification and is thus unaligned with the current spec."	defect	closed	minor		spec	VVC D7 vE	fixed		ksuehring bbross XiangLi fbossen jvet@…