Sub-picture sizing in video coding
A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising one or more sub-pictures partitioned from a picture such that each sub-picture includes a sub-picture width that is an integer multiple of a coding tree unit (CTU) size when the each sub-picture includes a right boundary that does not coincide with a right boundary of the picture. The bitstream is parsed to obtain the one or more sub-pictures. The one or more sub-pictures are decoded to create a video sequence. The video sequence is forwarded for display.
1. A method implemented in a by a decoder, the method comprising:
receiving a bitstream comprising a sequence parameter set (SPS) and one or more sub-pictures partitioned from a picture such that a first sub-picture includes more than one slice and includes an incomplete coding tree unit (CTU) when the first sub-picture includes a right boundary that coincides with the right boundary of the picture, wherein the SPS comprises a sub-picture identifier (ID), a sub-picture size, and a sub-picture location for each of the one or more sub-pictures;
parsing the bitstream to obtain the sub-picture ID, the sub-picture size, and the sub-picture location for each of the one or more sub-pictures;
decoding the one or more sub-pictures to create a video sequence; and
forwarding the video sequence for display.
2. The method of claim 1 , wherein a second sub-picture comprises a sub-picture height that includes an integer number of complete CTUs when the second sub-picture includes a bottom boundary that does not coincide with a bottom boundary of the picture.
3. The method of claim 1 , wherein a third sub-picture comprises a sub-picture width that includes an integer number of complete CTUs when the third sub-picture includes a right boundary that does not coincide with a right boundary of the picture.
4. The method of claim 1 , wherein a fourth sub-picture comprises a sub-picture height that includes an incomplete CTU when the fourth sub-picture includes a bottom boundary that coincides with the bottom boundary of the picture.
5. A method implemented by a decoder, the method comprising:
receiving a bitstream comprising a sequence parameter set (SPS) and a picture partitioned into sub-pictures, wherein at least one sub-picture includes more than one slice and includes an incomplete coding tree unit (CTU) when the at least one sub-picture includes a right boundary that coincides with the right boundary of the picture, wherein the SPS comprises a sub-picture identifier (ID), a sub-picture size, and a sub-picture location for each of the one or more sub-pictures;
determining a partitioning of the picture into the sub-pictures; and
decoding the picture based on the partitioning.
6. The method of claim 5 , wherein each sub-picture includes a sub-picture height that is an integer multiple of a CTU size when each sub-picture includes a bottom boundary that does not coincide with a bottom boundary of the picture.
7. The method of claim 5 , wherein each sub-picture includes a sub-picture width that is an integer multiple of a CTU size when each sub-picture includes a right boundary that does not coincide with a right boundary of the picture.
8. The method of claim 5 , wherein at least one of the sub-pictures includes a sub-picture height that is not an integer multiple of a CTU size when each sub-picture includes a bottom boundary that coincides with the bottom boundary of the picture.
9. The method of claim 5 , wherein the picture includes a picture width that is not an integer multiple of a CTU size.
10. The method of claim 5 , wherein the picture includes a picture height that is not an integer multiple of a CTU size.
11. The method of claim 5 , wherein a CTU size is measured in units of luma samples.
12. A decoder comprising:
a receiver configured to receive a bitstream comprising a sequence parameter set (SPS) and a picture partitioned into sub-pictures, wherein at least one sub-picture includes more than one slice and includes an incomplete coding tree unit (CTU) when the at least one sub-picture includes a right boundary that coincides with the right boundary of the picture, wherein the SPS comprises a sub-picture identifier (ID), a sub-picture size, and a sub-picture location for each of the one or more sub-pictures; and
a processor coupled to the receiver and configured to:
determine a partitioning of the picture into the sub-pictures; and
decode the picture based on the partitioning.
13. The decoder of claim 12 , wherein each sub-picture includes a sub-picture height that is an integer multiple of a CTU size when each sub-picture includes a bottom boundary that does not coincide with a bottom boundary of the picture.
14. The decoder of claim 12 , wherein each sub-picture includes a sub-picture width that is an integer multiple of a CTU size when each sub-picture includes a right boundary that does not coincide with a right boundary of the picture.
15. The decoder of claim 12 , wherein at least one of the sub-pictures includes a sub-picture height that is not an integer multiple of a CTU size when each sub-picture includes a bottom boundary that coincides with the bottom boundary of the picture.
16. The decoder of claim 12 , wherein the picture includes a picture width that is not an integer multiple of a CTU size.
17. The decoder of claim 12 , wherein the picture includes a picture height that is not an integer multiple of a CTU size.
18. The decoder of claim 12 , wherein a CTU size is measured in units of luma samples.