In HM-9.0, if the top-left corner of a chroma coding block of size 4x4 is aligned to a chroma location that is not a multiple of 8 in horizontal or vertical direction, the deblocking filter process is not applied to its left or top edge, respectively.

If that is the intended behavior, the text has to be modified. One possible solution would be to change:

In 8.7.2.4.1 Vertical edge filtering process:

– When bS[ xDk*2 ][ yDm*2 ] is greater than 1 and (( xDk >> 3 ) << 3) is equal to xDk, the following ordered steps apply.

to

– When bS[ xDk*2 ][ yDm*2 ] is greater than 1 and (( ( xC / 2 + xDk ) >> 3 ) << 3) is equal to xC / 2 + xDk, the following ordered steps apply.

and in 8.7.2.4.2 Horizontal edge filtering process:

– When bS[ xDk*2 ][ yDm*2 ] is greater than 1 and (( yDm >> 3 ) << 3) is equal to yDm, the following ordered steps apply.

to

– When bS[ xDk*2 ][ yDm*2 ] is greater than 1 and (( ( yC / 2 + yDm ) >> 3 ) << 3) is equal to yC / 2 + yDm, the following ordered steps apply.