Systems and methods for signaling temporal sub-layer information in video coding
This disclosure relates to video coding and more particularly to techniques for signaling temporal sub-layer information for coded video. According to an aspect of an invention, a range of a value of a third syntax element in a sequence parameter set is determined based on whether the sequence parameter set refers to a video parameter set, wherein the third syntax element specifies a maximum number of temporal sub-layers that is present in each coded video sequence referring to the sequence parameter set.
1. A method of decoding video data, the method comprising:
receiving a video parameter set;
parsing a first syntax element in the video parameter set wherein the first syntax element plus one specifies a maximum allowed number of layers in each coded video sequence referring to the video parameter set;
parsing a second syntax element in the video parameter set, wherein the second syntax element plus one specifies a maximum number of temporal sub-layers that may be present in a layer specified by the video parameter set;
parsing a third syntax element in the video parameter set, wherein a value of the third syntax element equal to 1 specifies that all layers are independently coded without using inter-layer prediction and the value of the third syntax element equal to 0 specifies that one or more of layers may use inter-layer prediction;
receiving a sequence parameter set;
parsing a fourth syntax element in the sequence parameter set; and
parsing a fifth syntax element in the sequence parameter set, wherein the fifth syntax element plus one specifies a maximum number of temporal sub-layers that may be present in each coded video sequence referring to the sequence parameter set,
wherein,
in a case that a value of the fourth syntax element is greater than 0,
the sequence parameter set refers to the video parameter set and a value of the fifth syntax element is in a range of 0 to a value of the second syntax element, and
in a case that the value of the fourth syntax element is equal to 0,
the sequence parameter set does not refer to the video parameter set, a value of the first syntax element is inferred to be equal to 0, the value of the third syntax element is inferred to be equal to 1, the value of the fifth syntax element is in a range of 0 to 6, and a value of a highest temporal sub-layer to be decoded is set equal to the value of the fifth syntax element.
2. A device comprising:
a processor, and
a memory associated with the processor; wherein the processor is configured to perform the following steps:
receiving a video parameter set;
parsing a first syntax element in the video parameter set, wherein the first syntax element plus one specifies a maximum allowed number of layers in each coded video sequence referring to the video parameter set;
parsing a second syntax element in the video parameter set, wherein the second syntax element plus one specifies a maximum number of temporal sub-layers that may be present in a layer specified by the video parameter set;
parsing a third syntax element in the video parameter set, wherein a value of the third syntax element equal to 1 specifies that all layers are independently coded without using inter-layer prediction and the value of the third syntax element equal to 0 specifies that one or more of layers may use inter-layer prediction;
receiving a sequence parameter set;
parsing a fourth syntax element in the sequence parameter set; and
parsing a fifth syntax element in the sequence parameter set, wherein the fifth syntax element plus one specifies a maximum number of temporal sub-layers that may be present in each coded video sequence referring to the sequence parameter set,
wherein,
in a case that a value of the fourth syntax element is greater than 0,
the sequence parameter set refers to the video parameter set and a value of the fifth syntax element is in a range of 0 to a value of the second syntax element, and
in a case that the value of the fourth syntax element is equal to 0,
the sequence parameter set does not refer to the video parameter set, a value of the first syntax element is inferred to be equal to 0, the value of the third syntax element is inferred to be equal to 1, the value of the fifth syntax element is in a range of 0 to 6, and a value of a highest temporal sub-layer to be decoded is set equal to the value of the fifth syntax element.