Opened 8 months ago

Closed 6 months ago

#706 closed defect (invalid)

Minor editorial issue for CclmEnabled derivation in 8.4.4

Reported by: chiaming Owned by:
Priority: minor Milestone:
Component: spec Version: VVC D7 vE
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

In 8.4.4, the CclmEnabled derivation is described as:

The variable, CclmEnabled is derived as follows:
– If sps_cclm_enabled_flag is equal to 0, CclmEnabled is set equal to 0.
– Otherwise, if one of the following conditions is true, CclmEnabled is set equal to 1:

– qtbtt_dual_tree_intra_flag is equal to 0.
– slice_type is not equal to I.
– CtbLog2SizeY is less than 6.

– Otherwise the following applies:

– The variables xCb64, yCb64, yCb32 are derived as follows:
...
– If one of the following conditions is true, the variable CclmEnabled is set equal to 1:

– CbWidth[ 1 ][ xCb64 ][ yCb64 ] is equal to 64 and CbHeight[ 1 ][ xCb64 ][ yCb64 ] is equal to 64.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6, MttSplitMode[ xCb64 ][ yCb64 ][ 0 ] is equal to SPLIT_BT_HOR, CbWidth[ 1 ][ xCb64 ][ yCb32 ] is equal to 64 and CbHeight[ 1 ][ xCb64 ][ yCb32 ] is equal to 32.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is greater than CtbLog2SizeY − 6.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6, MttSplitMode[ xCb64 ][ yCb64 ][ 0 ] is equal to SPLIT_BT_HOR, and MttSplitMode[ xCb64 ][ yCb32 ][ 1 ] is equal to SPLIT_BT_VER.

– Otherwise, the variable CclmEnabled is set equal to 0.

When CclmEnabled is equal to 1 and one of the following conditions is true, CclmEnabled is set equal to 0:
– CbWidth[ 0 ][ xCb64 ][ yCb64 ] and CbHeight[ 0 ][ xCb64 ][ yCb64 ] are both equal to 64, and intra_subpartitions_mode_flag[ xCb64 ][ yCb64 ] is equal to 1.
– CbWidth[ 0 ][ xCb64 ][ yCb64 ] or CbHeight[ 0 ][ xCb64 ][ yCb64 ] is less than 64, and CqtDepth[ 0 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6.

The above condition "When CclmEnabled is equal to 1 and..." (i.e., condition marked in red) should align with the condition "– If one of the following conditions is true, the variable CclmEnabled is set equal to 1:" (i.e., condition marked in blue). Two feasible editorial suggestions are given below:
(1) Add a indent in front of the condition "When CclmEnabled is equal to 1 and...". For example:

– Otherwise the following applies:

– The variables xCb64, yCb64, yCb32 are derived as follows:
...
– If one of the following conditions is true, the variable CclmEnabled is set equal to 1:

– CbWidth[ 1 ][ xCb64 ][ yCb64 ] is equal to 64 and CbHeight[ 1 ][ xCb64 ][ yCb64 ] is equal to 64.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6, MttSplitMode[ xCb64 ][ yCb64 ][ 0 ] is equal to SPLIT_BT_HOR, CbWidth[ 1 ][ xCb64 ][ yCb32 ] is equal to 64 and CbHeight[ 1 ][ xCb64 ][ yCb32 ] is equal to 32.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is greater than CtbLog2SizeY − 6.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6, MttSplitMode[ xCb64 ][ yCb64 ][ 0 ] is equal to SPLIT_BT_HOR, and MttSplitMode[ xCb64 ][ yCb32 ][ 1 ] is equal to SPLIT_BT_VER.

– Otherwise, the variable CclmEnabled is set equal to 0.
When CclmEnabled is equal to 1 and one of the following conditions is true, CclmEnabled is set equal to 0:
– CbWidth[ 0 ][ xCb64 ][ yCb64 ] and CbHeight[ 0 ][ xCb64 ][ yCb64 ] are both equal to 64, and intra_subpartitions_mode_flag[ xCb64 ][ yCb64 ] is equal to 1.
– CbWidth[ 0 ][ xCb64 ][ yCb64 ] or CbHeight[ 0 ][ xCb64 ][ yCb64 ] is less than 64, and CqtDepth[ 0 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6.

(2) Integrate conditions of "When CclmEnabled is equal to 1 and..." and "– If one of the following conditions is true, the variable CclmEnabled is set equal to 1:". For example:

– Otherwise the following applies:

– The variables xCb64, yCb64, yCb32 are derived as follows:
...
- If one of the following conditions is true, CclmEnabled is set equal to 0:

– CbWidth[ 0 ][ xCb64 ][ yCb64 ] and CbHeight[ 0 ][ xCb64 ][ yCb64 ] are both equal to 64, and intra_subpartitions_mode_flag[ xCb64 ][ yCb64 ] is equal to 1.
– CbWidth[ 0 ][ xCb64 ][ yCb64 ] or CbHeight[ 0 ][ xCb64 ][ yCb64 ] is less than 64, and CqtDepth[ 0 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6.

– Otherwise, if one of the following conditions is true, the variable CclmEnabled is set equal to 1:

– CbWidth[ 1 ][ xCb64 ][ yCb64 ] is equal to 64 and CbHeight[ 1 ][ xCb64 ][ yCb64 ] is equal to 64.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6, MttSplitMode[ xCb64 ][ yCb64 ][ 0 ] is equal to SPLIT_BT_HOR, CbWidth[ 1 ][ xCb64 ][ yCb32 ] is equal to 64 and CbHeight[ 1 ][ xCb64 ][ yCb32 ] is equal to 32.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is greater than CtbLog2SizeY − 6.
– CqtDepth[ 1 ][ xCb64 ][ yCb64 ] is equal to CtbLog2SizeY − 6, MttSplitMode[ xCb64 ][ yCb64 ][ 0 ] is equal to SPLIT_BT_HOR, and MttSplitMode[ xCb64 ][ yCb32 ][ 1 ] is equal to SPLIT_BT_VER.

– Otherwise, the variable CclmEnabled is set equal to 0.

Change history (2)

comment:1 Changed 8 months ago by bbross

  • Version changed from VVC D7 vD to VVC D7 vE

comment:2 Changed 6 months ago by bbross

  • Resolution set to invalid
  • Status changed from new to closed

I am kind of hesitating to make that change because I think it would change the conditions, hence it is not editorial.

The when condition is also checked if the very first conditions set CclmEnabled to 1.
When moving it to the otherwise part, that is not the case anymore.

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