Method and apparatus for encoding and decoding video using sub-picture partitioning

An apparatus for processing a bitstream generated by encoding a sequence of pictures each of which is partitioned into a plurality of subpictures, the apparatus comprising at least one processor configured to:

• decode, from a sequence parameter set referred to by all of the pictures belonging to the sequence, partitioning information indicating a partitioning structure in which the pictures belonging to the sequence are partitioned into the subpictures,
• wherein the partitioning structure defined by the partitioning information is identical for all of the pictures in the sequence, and
• wherein the partitioning information includes size information of the subpictures and position information of the subpictures;
• decode ID information for the subpictures, which is constructed to allow for mapping of different IDs to co-located subpictures that have a same position within different pictures belonging to the sequence, to map an ID to each of the subpictures;
• and
• reconstruct blocks within at least one subpicture corresponding to a mapped ID,
• wherein decoding the ID information comprises:
• decoding a syntax element for indicating whether ID mapping applies on a sequence level or not;
• when the syntax element indicates that the ID mapping applies on the sequence level, decoding the ID information from the sequence parameter set and thereby mapping the same ID to the co-located subpictures within all of the pictures belonging to the sequence;
• and
• when the syntax element indicates that the ID mapping does not apply on the sequence level, decoding the ID information from a picture parameter set referred to by one or more pictures belonging to the sequence and thereby mapping the same ID to the co-located subpictures within pictures referring to the picture parameter set.

A video encoding apparatus for encoding a sequence of pictures each of which is partitioned into a plurality of subpictures, the apparatus comprising at least one processor configured to:

• encode, into a sequence parameter set referred to by all of the pictures belonging to the sequence, partitioning information for indicating a partitioning structure in which the pictures belonging to the sequence are partitioned into the subpictures,
• wherein the partitioning structure defined by the partitioning information is identical for all of the pictures in the sequence, and
• wherein the partitioning information includes size information of the subpictures and position information of the subpictures;
• encode ID information for the subpictures which is constructed to allow for mapping of different IDs to co-located subpictures that have a same position within different pictures belonging to the sequence;
• and
• encode blocks within at least one subpicture corresponding to a mapped ID,
• wherein encoding the ID information comprises:
• encoding a syntax element for indicating whether ID mapping applies on a sequence level or not;
• when the syntax element indicates that the ID mapping applies on the sequence level, encoding the ID information into the sequence parameter set, for indicating that the same ID is mapped to the co-located subpictures within all of the pictures belonging to the sequence;
• and
• when the syntax element indicates that the ID mapping does not apply on the sequence level, encoding the ID information into a picture parameter set which is referred to by one or more pictures belonging to the sequence, for indicating that the same ID is mapped to the co-located subpictures within pictures referring to the picture parameter set.

An apparatus for transmitting a bitstream containing encoded video data, the apparatus comprising at least one processor configured to:

• generate the bitstream by encoding a sequence of pictures each of which is partitioned into a plurality of subpictures;
• and
• transmit the bitstream to a video decoding apparatus,
• wherein the generating the bitstream comprises:
• encoding, into a sequence parameter set referred to by all of the pictures belonging to the sequence, partitioning information for indicating a partitioning structure in which the pictures belonging to the sequence are partitioned into the subpictures,
• wherein the partitioning structure defined by the partitioning information is identical for all of the pictures in the sequence, and
• wherein the partitioning information includes size information of the subpictures and position information of the subpictures;
• encoding ID information for the subpictures which is constructed to allow for mapping of different IDs to co-located subpictures that have a same position within different pictures belonging to the sequence;
• and;
• and
• encoding blocks within at least one subpicture corresponding to a mapped ID,
• wherein encoding the ID information comprises:
• encoding a syntax element indicating whether ID mapping applies on a sequence level or not;
• when the syntax element indicates that the ID mapping applies on the sequence level, encoding the ID information into the sequence parameter set, for indicating that the same ID is mapped to the co-located subpictures within all of the pictures belonging to the sequence;
• and
• when the syntax element indicates that the ID mapping does not apply on the sequence level, encoding the ID information into a picture parameter set which is referred to by one or more pictures belonging to the sequence, for indicating that the same ID is mapped to the co-located subpictures within pictures referring to the picture parameter set.