wrong settings of variables related to ISP

[LiZhang]

In sub-clause 8.4.4.2.7, the setting of nW and nH is wrong.

The variables nW and nH are derived as follows:
– If IntraSubPartitionsSplitType is equal to ISP_NO_SPLIT or cIdx is not equal to 0, the following applies:

nW = nTbW (8-125)
nH = nTbH (8-126)

– Otherwise ( IntraSubPartitionsSplitType is not equal to ISP_NO_SPLIT and cIdx is equal to 0 ), the following applies:

nW = nCbW (8-127)
nH = nCbH (8-128)

The two cases should be reversed, i.e.,

The variables nW and nH are derived as follows:
– If IntraSubPartitionsSplitType is equal to ISP_NO_SPLIT or cIdx is not equal to 0, the following applies:

nW = nCbW (8-125)
nH = nCbH (8-126)

– Otherwise ( IntraSubPartitionsSplitType is not equal to ISP_NO_SPLIT and cIdx is equal to 0 ), the following applies:

nW = nTbW (8-127)
nH = nTbH (8-128)

[bbross]

It is correct since wide angle mode derivation:

• for ISP is based on the unpartioned TB sizes which correspond always to the CB sizes because ISP is not allowed for large blocks withg implicit TU split. Please note that nTbW and nTbH in the ISP case correspond to the subpartition width and height which are not used in this case

• for all other intra blocks, it is based on the TB sizes including implicit splits that's why it cannot be nCbW and nCbH in this case