general_non_packed_constraint_flag to ?

[haudiobe]

It says

H.4.2.6.1 SPS fields Sequence parameter set NAL units that occur within a CMAF scalable HEVC track shall conform to ISO/IEC 23008-2:2017, Annexes F and H with the following additional constraints: — The following fields shall have pre-determined values as follows: — general_progressive_source_flag shall be set to 1. — general_frame_only_constraint_flag shall be set to 1. — general_interlaced_source_flag shall be set to 0. — general_non_packed_constraint_flag shall be set to 0.

This is very uncommon, it is usually set to 1. Bug?

[cconcolato]

For context, from the HEVC spec:

general_non_packed_constraint_flag equal to 1 specifies that there are no frame packing arrangement SEI messages, segmented rectangular frame packing arrangement SEI messages, equirectangular projection SEI messages, or cubemap projection SEI messages present in the CVS. general_non_packed_constraint_flag equal to 0 indicates that there may or may not be one or more frame packing arrangement SEI messages, segmented rectangular frame packing arrangement SEI messages, equirectangular projection SEI messages, or cubemap projection SEI messages present in the CVS.

NOTE 2 – Decoders may ignore the value of general_non_packed_constraint_flag, as there are no decoding process requirements associated with the presence or interpretation of frame packing arrangement SEI messages, segmented rectangular frame packing arrangement SEI messages, equirectangular projection SEI messages, or cubemap projection SEI messages.

Given the above text, I can imagine that 0 was chosen to: reduce syntax options (no need to check conformance for 0 and 1), while retaining all options (presence or absence of the SEI messages). I'm not sure it's worth changing it.

[haudiobe]

This is fixed in the draft third edition and can be closed.

[cconcolato]

What did you fix?

[haudiobe]

The issue is addressed in the draft third edition.

We propose to close the issue.