Systems and methods for signaling tile group information in video coding

1. A method of decoding video data, the method comprising:

receiving a picture parameter set; and

parsing, from the picture parameter set, a first syntax element specifying a difference between a first index of a tile located in a first tile group and a second index of a tile located in a second tile group, wherein the first tile group is an i-th tile group and the second tile group is an (i+1)-th tile group.

2. The method of claim 1 , wherein the first tile group is a first slice comprising a first integer number of complete tiles and the second tile group is a second slice comprising a second integer number of complete tiles.

3. The method of claim 1 , wherein the first index is an index of a top-left tile in the first tile group and the second index is an index of a top-left tile in the second tile group.

4. The method of claim 1 , further comprising:

parsing, from the picture parameter seta second syntax element specifying that tiles within each of the first tile group and the second tile group cover respective rectangular regions of a picture, wherein tile group information is signaled in the picture parameter set.

5. The method of claim 4 , wherein the first syntax element is conditionally present when the second syntax element is not equal to zero.

6. The method of claim 4 , further comprising:

parsing, from the picture parameter set, a third syntax element specifying whether each picture partition at a first picture partitioning level is allowed to include more than one picture partition at a second partitioning level.

7. The method of claim 6 , wherein the first syntax element is conditionally present when the second syntax element is not equal to zero and the third syntax element is equal to zero.

8. The method of claim 7 , wherein the third syntax element being equal to zero specifies that the tile group includes the more than one tile.

9. The method of claim 6 , wherein each picture partition at the first picture partitioning level is a tile group in a picture referring to the picture parameter set, and the more than one picture partition at the second partitioning level is more than one tile in the tile group.

10. The method of claim 1 , wherein:

the difference is a first difference, and

the first syntax element further specifies a second difference between the second index of the tile located in the second tile group and a third index of a tile located in a third tile group.

11. The method of claim 1 , wherein parsing, from the picture parameter set, the first syntax element comprises, for each respective tile group of a plurality of tile groups, parsing a difference between the respective tile group and another tile group of the plurality of tile groups.

12. The method of claim 11 , further comprising:

parsing, from the picture parameter set, a second syntax element specifying a number of tile groups in the plurality of tile groups.

13. The method of claim 12 , wherein the number of tile groups in the plurality of tile groups is a number of tile groups in a picture minus 1.

14. The method of claim 11 , wherein:

the plurality of tile groups is ordered for each respective tile group in the plurality of tile groups, and

the other tile group is next to the respective tile group in the order.