id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
1366	Inference of cu_skip_flag and tu_y_coded_flag for dual tree IBC	bheng		"
1.) If ""when not present"" in the following statements is interpreted to mean not present for either the DUAL_TREE_LUMA or DUAL_TREE_CHROMA parsing at location [x0][y0],

   When cu_skip_flag[ x0 ][ y0 ] is not present, it is inferred to be equal to 0.
   When tu_y_coded_flag[ x0 ][ y0 ] is not present, its value is inferred as follows...
   
then I think the inference of pred_mode_ibc_flag for DUAL_TREE_CHROMA below should be moved first in this list. Otherwise the cu_skip_flag[ x0 ][ y0 ] from the DUAL_TREE_LUMA CU will be used for the DUAL_TREE_CHROMA CU.

   –	If cu_skip_flag[ x0 ][ y0 ] is equal to 1, and cbWidth is equal to 4, and cbHeight is equal to 4, pred_mode_ibc_flag is inferred to be equal 1.
   –	Otherwise, if cu_skip_flag[ x0 ][ y0 ] is equal to 1 and modeType is equal to MODE_TYPE_INTRA, pred_mode_ibc_flag is inferred to be equal 1.
   –	Otherwise, if either cbWidth or cbHeight are equal to 128, pred_mode_ibc_flag is inferred to be equal to 0.
   –	Otherwise, if modeType is equal to MODE_TYPE_INTER, pred_mode_ibc_flag is inferred to be equal to 0.
   –	Otherwise, if treeType is equal to DUAL_TREE_CHROMA, pred_mode_ibc_flag is inferred to be equal to 0.
   –	Otherwise, pred_mode_ibc_flag is inferred to be equal to the value of sps_ibc_enabled_flag when decoding an I slice, and 0 when decoding a P or B slice, respectively.


2.) Alternatively, if ""when not present"" above is interpreted to mean not present in the current CU exclusively (neither of these syntax elements will ever be present in a DUAL_TREE_CHROMA CU), then I believe the following should not apply for DUAL_TREE_CHROMA treeType.

   The variable CuSkipFlag[ x ][ y ] is set equal to cu_skip_flag[ x0 ][ y0 ] for x = x0..x0 + cbWidth - 1, y = y0..y0 + cbHeight - 1.

   if treeType is equal to DUAL_TREE_CHROMA, tu_y_coded_flag[ x0 ][ y0 ] is inferred to be equal to 0.

Otherwise, the DUAL_TREE_CHROMA CU will erase the CuSkipFlag and tu_y_coded_flag from the DUAL_TREE_LUMA CU, which are required for IBC skip context derivation and deblocking."	defect	closed	minor		spec	VVC D10 vG	fixed		ksuehring bbross XiangLi fbossen jvet@…