JVET-X0050 AHG2: On editing notes for the 2nd edition draft text of VVC [Y.-K. Wang (Bytedance), M. Zhou (Broadcom)]
This contribution discusses the editing notes for the 2nd edition draft text of VVC, with suggestions for some of them.
1 On signalling of general_lower_bit_rate_constraint_flag
During the discussion, another suggestion is made to infer the flag for certain profiles. T. Ikai was asked to provide a corresponding text (see contribution JVET-X0187, which however became obsolete by the decision to remove that flag).
2 On semantics of sh_entry_point_offset_minus1[ i ]
Regarding the first editing note, indeed it would make more sense to just remove ", and the number of subsets shall be 1", or change it to be ", i.e., the number of subsets is equal to 1", as it has been established above that the number of subsets is equal to NumEntryPoints + 1. A similar change should be made to HEVC.
This change is agreed. The two solutions are equivalent, and it was left to editors which one is selected. Also include in HEVC related errata items.
Regarding the second editing note, the requirement would be violated when the encoder puts wrong values for the instances of sh_entry_point_offset_minus1[ i ] that for example would split coded bits of one CTU into different subsets or the coded bits of some CTUs of a slice in one subset and the coded bits of other CTUs of the same slice into another subset in this case.
Agreed that no action should be taken. May be further studied to impose it as semantics constraint rather than encoder constraint.
3 On the semantics of amvr_flag[ x0 ][ y0 ]
Agreed. Replace “difference” by “differences” (3x), and clarify that this refers to the current CU.
4 On CpbVclFactor, CpbNalFactor, FormatCapabilityFactor and MinCrScaleFactor for 12-bit profiles
Other contributions on this topic in 4.12 – see further discussion there.
5 On the informative tables showing effect of level limits on picture rate
It was agreed to add mentioning the new profiles in the informative table.
6 On the addition of specifications for use of some SEI messages specified in the VSEI spec
No action was necessary on this item.