Opened 3 years ago

Closed 3 years ago

#1445 closed defect (worksforme)

Missing condition in restriction of sh_picture_header_in_slice_header_flag

Reported by: martin.m.pettersson Owned by:
Priority: minor Milestone:
Component: spec Version: VVC D10 vH
Keywords: Cc: ksuehring, bbross, XiangLi, fbossen, jvet@…

Description

In JVET-T2001-v2 the following restriction is present in section 7.4.2.4.4:

When a picture consists of more than one VCL NAL unit, a PH NAL unit shall be present in the PU.

and the following restriction is present in section 7.4.8:

When any of the following conditions is true, the value of sh_picture_header_in_slice_header_flag shall be equal to 0:
- The value of sps_subpic_info_present_flag is equal to 1.
- The value of pps_rect_slice_flag is equal to 0.
- The value of pps_rpl_info_in_ph_flag, pps_dbf_info_in_ph_flag, pps_sao_info_in_ph_flag, pps_alf_info_in_ph_flag, pps_wp_info_in_ph_flag, or pps_qp_delta_info_in_ph_flag is equal to 1.

To be in line with the first restriction it seems like the second restriction should be extended to include that the sh_picture_header_in_slice_header_flag shall be equal to 0 when there is more than one slice in the picture. A suggestion is to extend the second restriction as follows:

When any of the following conditions is true, the value of sh_picture_header_in_slice_header_flag shall be equal to 0:
- The value of sps_subpic_info_present_flag is equal to 1.
- The value of pps_rect_slice_flag is equal to 0.
- The value of pps_rpl_info_in_ph_flag, pps_dbf_info_in_ph_flag, pps_sao_info_in_ph_flag, pps_alf_info_in_ph_flag, pps_wp_info_in_ph_flag, or pps_qp_delta_info_in_ph_flag is equal to 1.
- The value of pps_num_slices_in_pic_minus1 is greater than 0.

Change history (2)

comment:1 Changed 3 years ago by yk

To me, that addition is not necessary as the above-mentioned restriction in clause 7.4.2.4.4 implies it already. Actually, that restriction in clause 7.4.2.4.4 implies that whenever a picture contains more than one slice, the value of sh_picture_header_in_slice_header_flag for each of the slices in the picture has to be equal to 0. I personally don't see the need even for a NOTE; but if people think it is better to explicitly express this, it's OK to me add the NOTE.

Opinions?

comment:2 Changed 3 years ago by yk

  • Resolution set to worksforme
  • Status changed from new to closed
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