Explicit address signaling in video coding
A video coding mechanism is disclosed. The mechanism includes receiving a sub-bitstream including: a sub-picture of a picture partitioned into a plurality of slices including a first slice, a parameter set associated with the picture and the sub-picture, and a slice header associated with the first slice. The parameter set is parsed to obtain an identifier and a length of a slice address of the first slice. A slice address for the first slice is determined from the slice header based on the identifier and the length of the slice address. The sub-bitstream is decoded to create a video sequence of sub-pictures including the first slice. The video sequence of sub-pictures is forwarded for display.
1. A method implemented by a decoder, the method comprising:
receiving a sub-bitstream including: a sub-picture of a picture partitioned into a plurality of slices including a first slice, a parameter set associated with the picture and the sub-picture, and a slice header associated with the first slice;
parsing the parameter set to obtain an identifier and a length of a slice address of the first slice;
determining the slice address for the first slice from the slice header based on the identifier and the length of the slice address, wherein determining the slice address for the first slice comprises:
employing the length from the parameter set to determine bit boundaries for interpreting the slice address from the slice header; and
employing the identifier and the slice address to map slice addresses between a picture based position and a sub-picture based position;
decoding the sub-bitstream to create a video sequence of sub-pictures including the first slice; and
forwarding the video sequence of the sub-pictures for display.
2. The method of claim 1 , wherein the identifier is associated with a the sub-picture.
3. The method of claim 1 , wherein the length of the slice address indicates a number of bits contained in the slice address.
4. The method of claim 1 , further comprising parsing the parameter set to obtain a flag, wherein the flag indicates a mapping is available to map the slice address from the picture based position to the sub-picture based position.
5. The method of claim 4 , wherein the mapping between the picture based position and the sub-picture based position aligns the slice header to the sub-picture without requiring that the slice header be rewritten.
6. A method implemented by an encoder, the method comprising:
encoding a picture in a bitstream, wherein the picture comprises a plurality of slices including a first slice;
encoding in the bitstream a slice header including a slice address of the first slice;
encoding in the bitstream a parameter set including an identifier and a length of the slice address of the first slice, wherein the length in the parameter set contains data sufficient to interpret the slice address from the slice header, and wherein the identifier contains data sufficient to map slice addresses between a sub-picture based position and a picture based position;
extracting a sub-bitstream of the bitstream by extracting the first slice based on the slice address of the first slice, the length of the slice address, and the identifier without rewriting the slice header; and
storing the sub-bitstream for communication toward a decoder.
7. The method of claim 6 , wherein the identifier is associated with a sub-picture.
8. The method of claim 6 , wherein the length of the slice address indicates a number of bits contained in the slice address.
9. The method of claim 6 , further comprising encoding in a the parameter set a flag indicating a mapping is available to map the slice address from the picture based position to the sub-picture based position.
10. The method of claim 6 , wherein extracting the sub-bitstream of the bitstream includes extracting a sub-picture of the picture, the sub-picture including the first slice, and wherein the sub-bitstream comprises the sub-picture, the slice header, and the parameter set.
11. A video coding device comprising:
a receiver configured to receive a sub-bitstream including: a sub-picture of a picture partitioned into a plurality of slices including a first slice, a parameter set associated with the picture and the sub-picture, and a slice header associated with the first slice; and
a processor configured to:
parse the parameter set to obtain an identifier and a length of a slice address of the first slice;
determine the slice address for the first slice from the slice header based on the identifier and the length of the slice address, wherein determining the slice address for the first slice comprises:
employing the length from the parameter set to determine bit boundaries for interpreting the slice address from the slice header; and
employing the identifier and the slice address to map slice addresses between a sub-picture based position and a picture based position;
decode the sub-bitstream to create a video sequence of sub-pictures including the first slice; and
forward the video sequence of the sub-pictures for display.
12. The video coding device of claim 11 , wherein the identifier is associated with a the sub-picture.
13. The video coding device of claim 11 , wherein the length of the slice address indicates a number of bits contained in the slice address.
14. The video coding device of claim 11 , wherein the processor is further configured to parse the parameter set to obtain a flag, wherein the flag indicates a mapping is available to map the slice address from the picture based position to the sub-picture based position.
15. The video coding device of claim 14 , wherein the mapping between the picture based position and the sub-picture based position aligns the slice header to the sub-picture without requiring that the slice header be rewritten.