id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
1225	4:2:2 and 4:4:4 chroma cbf coding	kazui.kimihiko@…		"
In both 4:2:2 and 4:4:4 the transform tree syntax doesn't provide for non non-zero TBs.

(Reminder), For 4:2:0, an 8x8 TU that is split to four 4x4 TUs will have a single 4x4 chroma TB coded.  The chroma CBF for this single 4x4 TB is that from the level above (ie 8x8).

(1)
In the case of 4:2:2, which follows the 4:2:0 design, there are two 'leaf' 4x4 chroma TBs.  The current spec has the issue that both chroma TBs inherit the CBF from the level above, requiring both to contain sig coefs.

(2)
In the case of 4:4:4, which allows the equal splitting of luma and chroma blocks (ie an 8x8CU can be split into four 4x4 luma TBs and four 4x4 Cb TBs), all 4x4 chroma TBs will inherit the CBF from the level above.
"	defect	closed	major	RExt D7	RExt text	RExt D5 (O1005) v3	fixed		davidf joel teruhiko jct-vc@…