id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
636	Editorial modifications from JVET-P0626 create reference to undefined value	fbossen		"JVET-P0626 modifies the range of values to which equations (8-134) and (8-144) are applied. With this modification, equations (8-138) and (8-148) can reference undefined values.

For example when nTbW = 8, nTbH = 16, refIdx = 0 and intraPredAngle = 16, equation (8-138) may refer to ref[18]. This happens when x = 7, y = 15:
From equation (8-135) iIdx = 16 * 16 >> 5 = 8
In equation (8-138) x + iIdx + i = 7 + 8 + 3 = 18 which is used to index ref[]

However, equation (8-134) defines ref[i] only up to i=17.
The largest index for which ref[] is defined is refW + refIdx + x = 17, where refW = 2 * 8 = 16, refIdx = 0, and x = 1 (was x = 2 before JVET-P0626 modifications)

It is suggested to revert the JVET-P0626 modifications to avoid referencing undefined values (even though they end up being multiplied by 0).

The application of the JVET-P0626 modifications in SW have led to bug report #635. The modifications are thus also proposed to be reverted in SW.
"	defect	closed	minor		spec	VVC D8 vB	wontfix		ksuehring bbross XiangLi fbossen jvet@…