JVET-X0093 AHG2/AHG8: Comments on VVC operation range extensions [B. Choi, S. Wenger, S. Liu (Tencent)]
The following modifications are proposed to improve the VVC operation range extension specifications:
Proposal-1: Add the constraint that vps_max_layers_minus1 shall be equal to 0 in the format range extension profiles.
Multilayer operation is already disabled by the ptl_multilayer_enabled_flag equal 0. Not clear if any action is necessary – it was clarified offline that there is no issue with semantics.
Proposal-2: Update the value range of the syntax element sps_bitdepth_minus8 in VPS to cover the extended bitdepth range.
It was agreed that a change is necessary. Another option could be to just remove the constraint, as it is anyway specified in the annex. It was agreed to follow the HEVC style, change “2” to “8”, but without the reference to the annex.
Proposal-3: Add the description that clarifies the meaning of “-“ in the Table A.1.
It was agreed that a change is necessary. See further discussion under JVET-X0073.
Proposal-4: Replace “active SPSs” with “referenced SPSs”.
This was agreed.