Implicit signaling of scalability dimension identifier information in a parameter set
A system for decoding a video bitstream includes receiving a frame of the video that includes at least one slice and at least one tile and where each of the at least one slice and the at least one tile are not all aligned with one another.
1. A method for decoding a coded video sequence comprising:
receiving a video syntax set that includes information applicable to said coded video sequence;
determining, based on a flag included in said video syntax, that a scalability dimension identifier for said coded video sequence is implicitly signaled, wherein the flag is indicative of either implicit or explicit signaling of the scalability dimension identifier,
wherein said scalability dimension identifier specifies a scalability dimension of a particular layer of said coded video sequence, the scalability dimension being one of multiple types, including: a spatial type and a quality type;
deriving the scalability dimension identifier from a network abstraction layer (NAL) unit header in response to determining that the scalability dimension identifier is implicitly signaled;
decoding an enhancement layer based on the scalability dimension; and
generating a decoded video sequence based on, in part, the enhancement layer.
2. The method of claim 1 wherein said flag with a value of 1 specifies said explicit signaling of said scalability dimension identifier.
3. The method of claim 2 wherein said scalability dimension identifier is a dimension_id[i][j] , where i specifies said particular layer and j specifies said scalability dimension type of said particular layer.
4. The method of claim 1 wherein said flag with a value of 0 specifies said implicit signaling of said scalability dimension identifier.
5. The method of claim 4 wherein said scalability dimension identifier is a dimension_id[i][j] , where i specifies said particular layer and j specifies said scalability dimension type of said particular layer.
6. The method of claim 1 wherein said implicit or explicit signaling uses a syntax including if(!flag) condition.
7. The method of claim 1 wherein said scalability dimension identifier specifies more than one identifier of a plurality of scalability dimension types of a particular layer of said coded video sequence.
8. The method of claim 4 wherein said flag with a value of 0 specifies said implicit signaling of said scalability dimension identifier where values of the scalability dimension identifier are derived based on other information signaled in video syntax set.
9. The method of claim 8 wherein the other information signaled in video syntax set used for derivation of scalability dimension identifier includes information about length in bits of scalability dimension identifier.
10. The method of claim 9 wherein the length in bits of scalability dimension identifier is dimension_id_len_minus1[i].
11. The method of claim 1 , wherein said scalability dimension identifier specifies the scalability dimension as being of the quality type.
12. The method of claim 1 further comprising:
receiving the coded video sequence in the form of at least two separate bitstreams, the at least two bitstreams comprising a first bitstream representing a base layer, and at least a second bitstream representing an enhancement layer.