Decoder and decoding method
According to one aspect of the present disclosure, a decoder includes memory and a processor coupled to the memory. The processor is configured to split a current picture into tiles, generate a slice having a rectangular shape and located at a lower-right corner of the current picture, the slice including at least a part of a tile among the tiles, generate first information on a region of the slice with header information, the header information not including information identical to the first information, and decode the slice with the first information.
1. A decoder that decodes an image, the decoder comprising:
circuitry; and
memory coupled to the circuitry, wherein
in operation, the circuitry:
splits a current picture to be decoded into two or more tiles; and
decodes the current picture by performing the decoding on a slice, the slice being rectangular-shaped, the slice being made up of one or more tiles or a part of a tile obtained by the splitting,
in the decoding of the current picture, the circuitry sets first information on a region in a predetermined manner without retrieving the first information from header information, the region being occupied by a slice located at a lower-right corner of the current picture, and
the first information is not included in the header information.
2. The decoder according to claim 1 , wherein
the first information is information indicating a position of a lower-right corner of the slice located at the lower-right corner of the current picture.
3. The decoder according to claim 1 , wherein
the first information is information indicating a position of an upper-left corner and a position of a lower-right corner of the slice located at the lower-right corner of the current picture.
4. The decoder according to claim 1 , wherein
the first information is information represented by syntax.
5. The decoder according to claim 1 , wherein
in operation, the circuitry further
in the decoding of the current picture, decodes position information of an upper-left corner of a slice located at the beginning of the current picture from information indicating a position of an upper-left corner of the current picture, the information indicating the position of the upper-left corner of the current picture being included in the header information.
6. The decoder according to claim 1 , wherein
the predetermined manner is
calculating the first information using second information included in the header information and different from the first information.
7. The decoder according to claim 6 , wherein
the second information is a tile index or a tile index difference included in the header information.
8. The decoder according to claim 7 , wherein
the tile index difference is a difference between (i) a tile index of a tile located at an upper-left corner of the slice located at the lower-right corner of the current picture and (ii) a tile index of a tile located at a lower-right corner of the slice located at the lower-right corner of the current picture.
9. A decoding method of decoding an image, the decoding method comprising:
splitting a current picture to be decoded into two or more tiles; and
decoding the current picture by performing the decoding on a slice, the slice being rectangular-shaped, the slice being made up of one or more tiles or a part of a tile obtained by the splitting, wherein
the decoding of the current picture includes setting first information on a region in a predetermined manner without retrieving the first information from header information, the region being occupied by a slice located at a lower-right corner of the current picture, and
the first information is not included in the header information.
10. A decoder comprising:
memory; and
a processor coupled to the memory and configured to:
split a current picture into tiles;
generate a slice having a rectangular shape and located at a lower-right corner of the current picture, the slice including at least a part of a tile among the tiles;
generate first information on a region of the slice with header information, the header information not including information identical to the first information; and
decode the slice with the first information.
11. The decoder according to claim 10 , wherein the processor is configured to generate the first information with second information which is different from the first information and which is included in the header information.
12. The decoder according to claim 11 , wherein the second information indicates one of a tile index and a difference of tile indices.
13. The decoder according to claim 12 , wherein the difference is a difference between (i) a first tile index of a first tile located at an upper-left corner of the slice and (ii) a second tile index of a second tile located at a lower-right corner of the slice.