Sub-pictures and sub-picture sets with level derivation

1 . An apparatus comprising:

interface circuitry;

machine-readable instructions; and

at least one processor circuit to be programmed based on the machine-readable instructions to:

populate a supplemental enhancement information (SEI) message with a value corresponding to a number of subpictures of a video sequence;

populate a level indicator in the SEI message;

populate a subpicture identifier;

populate the subpicture identifier in a slice header;

set a flag in the SEI message to indicate that tier information is present in a sequence parameter set syntax structure; and

cause the SEI message and the slice header to be included in a video bitstream.

2 . The apparatus of claim 1 , wherein the level indicator is to indicate decoder interoperability for the video sequence.

3 . The apparatus of claim 1 , wherein one or more of the at least one processor circuit is to populate a maximum sublayers value in the sequence parameter set syntax structure.

4 . The apparatus of claim 1 , wherein one or more of the at least one processor circuit is to populate a number of sublayers value in the sequence parameter set syntax structure.

5 . The apparatus of claim 1 , wherein the video sequence is a coded video sequence.

6 . The apparatus of claim 1 , wherein one or more of the at least one processor circuit is to determine the level indicator based on sealing a max luma sample rate for a level of the video sequence scaled by a ratio of a subpicture set size to a picture size.

7 . The apparatus of claim 1 , wherein one or more of the at least one processor circuit is to:

populate the subpicture identifier in the sequence parameter set syntax structure; and

cause the sequence parameter set syntax structure to be included in the video bitstream.

8 . The apparatus of claim 1 , wherein the subpicture identifier is associated with a slice corresponding to the slice header.

9 . At least one non-transitory machine-readable medium comprising machine-readable instructions to cause at least one processor circuit to at least:

populate a supplemental enhancement information (SEI) message with a value corresponding to a number of subpictures of a video sequence;

populate a level indicator in the SEI message;

populate a subpicture identifier;

populate the subpicture identifier in a slice header;

set a flag in the SEI message to indicate that tier information is present in a sequence parameter set syntax structure; and

cause the SEI message and the slice header to be included in a video bitstream.

10 . The at least one non-transitory machine-readable medium of claim 9 , wherein the machine-readable instructions are to cause one or more of the at least one processor circuit to populate a maximum sublayers value in the sequence parameter set syntax structure.

11 . The at least one non-transitory machine-readable medium of claim 9 , wherein the machine-readable instructions are to cause one or more of the at least one processor circuit to populate a number of sublayers value in the sequence parameter set syntax structure.

12 . The at least one non-transitory machine-readable medium of claim 9 , wherein the machine-readable instructions are to cause one or more of the at least one processor circuit to determine the level indicator based on a max luma sample rate for a level of the video sequence scaled by a ratio of a subpicture set size to a picture size.

13 . The at least one non-transitory machine-readable medium of claim 9 , wherein the machine-readable instructions are to cause one or more of the at least one processor circuit to:

populate the subpicture identifier in the sequence parameter set syntax structure; and

cause the sequence parameter set syntax structure to be included in the video bitstream.

14 . The at least one non-transitory machine-readable medium of claim 9 , wherein the subpicture identifier is associated with a slice corresponding to the slice header.

15 . An apparatus comprising:

interface circuitry;

machine-readable instructions; and

at least one processor circuit to be programmed by the machine-readable instructions to:

access a video bitstream;

access a subpicture identifier in a slice header of the video bitstream;

identify a subpicture set from the video bitstream to be decoded;

decode a level indicator for the subpicture set based on a supplemental enhancement information (SEI) message in the video bitstream; and

determine whether the level indicator satisfies a threshold.

16 . The apparatus of claim 15 , wherein the level indicator is to indicate decoder interoperability for the video bitstream.

17 . The apparatus of claim 15 , wherein the subpicture identifier is associated with a slice corresponding to the slice header.

18 . The apparatus of claim 15 , wherein the video bitstream is based on 360 video coding, and one or more of the at least one processor circuit is to:

select the subpicture set from a region of the 360 video coding of the video bitstream; and

decode the subpicture set.

19 . The at least one non-transitory machine-readable medium of claim 9 , wherein the level indicator is to indicate decoder interoperability for the video sequence.