Image coding method, image decoding method, image coding apparatus, image decoding apparatus, and image coding and decoding apparatus
A dependency indication is signaled within the beginning of a packet, that is, within the adjacent of a slice header to be parsed or a parameter set. This is achieved, for example, by including the dependency indication at the beginning of the slice header, preferably after a syntax element identifying the parameter set and before the slice address, by including the dependency indication before the slice address, by providing the dependency indication to a NALU header using a separate message, or by using a special NALU type for NALUs carrying dependent slices.
1. An image decoding method for decoding a picture, the image decoding method comprising:
decoding, from a coded bitstream:
a dependent slice enabling flag indicating whether or not a dependent slice is enabled for the picture, wherein the dependent slice is a slice on which the decoding processing is performed by at least partially using control information included in a header of a slice different from the dependent slice;
determining a value indicating whether or not the picture is a random access picture, and, subsequent to determining whether the picture is a random access picture, decoding, from a coded bitstream;
i.) a slice address indicating a starting position of a current slice of the picture; and
ii.) a dependency indication indicating whether or not the current slice is the dependent slice;
wherein;
the dependent slice enabling flag is disposed in a parameter set common to all slices of the picture;
the slice address is disposed in a slice header of the current slice; and,
the dependency indication is disposed in the slice header of the current slice before the slice address and after a syntax element identifying the parameter set.
2. The image decoding method according to claim 1 , wherein the dependency indication is extracted from the bitstream when the dependent slice enabling flag indicates the dependent slice is enabled for the picture.
3. The image decoding method according to claim 1 , wherein the dependent slice enabling flag is disposed at a beginning of the parameter set.
4. The image decoding method according to claim 1 , wherein the dependency indication is not included in a slice header of a slice which is processed first for the picture.
5. An image decoding apparatus for decoding a picture, the image decoding apparatus comprising:
at least one processor;
at least one memory including computer program code, the memory and the computer program code configured to, working with the at least one processor;
decode, from a coded bitstream:
a dependent slice enabling flag indicating whether or not a dependent slice is enabled for the picture, on which the decoding processing is performed by at least partially using control information included in a header of a slice which is different from the dependent slice;
determine a value indicating whether or not the picture is a random access picture, and, subsequent to the determination whether the picture is a random access picture, decode from the decoded bitstream;
i.) a slice address indicating a starting position of a current slice of the picture; and
ii.) a dependency indication indicating whether or not the current slice is the dependent slice;
wherein;
the dependent slice enabling flag is disposed in a parameter set common to all slices of the picture;
the slice address is disposed in a slice header of the current slice; and
the dependency indication is disposed in the slice header of the current slice before the slice address and after a syntax element identifying the parameter set.
6. The image decoding apparatus according to claim 5 , wherein the dependency indication is extracted from the bitstream when the dependent slice enabling flag indicates the dependent slice is enabled for the picture.
7. The image decoding apparatus according to claim 5 , wherein the dependent slice enabling flag is disposed at a beginning of the parameter set.
8. The image decoding apparatus according to claim 5 , wherein the dependency indication is not included in a slice header of a slice which is processed first for the picture.
9. A non-transitory computer-readable medium storing instructions which, when executed by a processor, perform the acts of:
decoding, from a coded bitstream:
a dependent slice enabling flag indicating whether or not a dependent slice is enabled for a picture, on which the decoding processing is performed by at least partially using control information included in a header of a slice which is different from the dependent slice;
determining a value indicating whether or not the picture is a random access picture, and, subsequent to determining whether the picture is a random access picture, decoding from the decoded bitstream;
i.) a slice address indicating a starting position of a current slice of the picture; and
ii.) a dependency indication indicating whether or not the current slice is the dependent slice;
wherein:
the dependent slice enabling flag is disposed in a parameter set common to all slices of the picture;
the slice address is disposed in a slice header of the current slice; and
the dependency indication is disposed in the slice header of the current slice before the slice address and after a syntax element identifying the parameter set.
10. The non-transitory computer-readable medium according to claim 9 , wherein the dependency indication is extracted from the bitstream when the dependent slice enabling flag indicates the dependent slice is enabled for the picture.
11. The non-transitory computer-readable medium according to claim 9 , wherein the dependent slice enabling flag is disposed at a beginning of the parameter set.
12. The non-transitory computer-readable medium according to claim 9 , wherein the dependency indication is not included in a slice header of a slice which is processed first for the picture.