JVET-S0047 AHG9: Signalling of Virtual Boundary Positions [M. Damghanian, R. Sjöberg, M. Pettersson, Z. Zhang, J. Enhorn, J. Ström, R. Yu, D. Liu (Ericsson)]
This contribution was discussed in the HLS AHG meeting at 0837 UTC on Thursday 28 May and in the main JVET meeting at 1340 on 25 June (chaired by GJS).
At the 18th JVET meeting, it was decided (in JVET-R0266 item 6) to code virtual boundary positions using ue(v) for the sps_virtual_boundary_pos_x, sps_virtual_boundary_pos_y, ph_virtual_boundary_pos_x and ph_virtual_boundary_pos_y syntax elements instead of fixed length coding using u(13). It is observed that the value of 0 is not allowed for these four syntax elements so this contribution proposes to align the semantics of these four syntax elements with other syntax elements in the specification and use the minus1 mechanism. The following changes to the syntax and semantics are proposed:
- Add “_minus1” to each of the four syntax elements sps_virtual_boundary_pos_x, sps_virtual_boundary_pos_y, ph_virtual_boundary_pos_x and ph_virtual_boundary_pos_y.
- Update the corresponding ranges and derivations in the semantics of the four syntax elements accordingly.
AHG Recommendation (cleanup): Adopt.