NAL Unit Header
Disclosed are techniques for scalable, multiview, and multiple descriptive video coding using an improved Network Adaptation Layer (NAL) unit header. A NAL unit header can include a layer-id that can be a reference into a table of layer descriptions, which specify the properties of the layer. The improved NAL unit header can further include fields for reference picture management and to identify temproal layers.
1 . A method for video decoding, comprising:
receiving a table of layer descriptions comprising at least one layer description identified by a first layer_id;
receiving a NAL unit header comprising a second layer_id; and
determining at least one property of the layer that the NAL unit belongs to by matching the second layer_id with the first layer_id.
2 . The method of claim 1 , wherein the at least one property comprises at least one of: a dependency_id, a quality_id, a temporal_id, a view_id, a depth_map_flag, and a dependent_flag.
3 . The method of claim 1 , wherein the NAL unit header further comprises a temporal_id.
4 . The method of claim 3 , wherein the temporal_id identifies a temporal sub-layer of a layer identified by the layer_id.
5 . The method of claim 1 , wherein the table of layer descriptions is part of a dependency parameter set.
6 . The method of claim 2 , wherein the depth_map_flag indicates that the first layer the NAL unit belongs to is a depth map, and is associated with a second layer identified by having the same view_id as the first layer.
7 . The method of claim 1 , wherein a predefined value for the second layer_id identifies the presence of extension data.
8 . The method of claim 1 , wherein the first layer_id is an indication of a position of the layer in a layer hierarchy.
9 . The method of claim 1 , wherein the NAL unit header further comprises at least one of: a store_ref_base_pic_flag and a use_ref_base_pic_flag.
10 . The method of claim 1 , wherein the NAL unit header is a slice NAL unit header, and the slice header of the slice carried in the NAL unit comprises at least one of a store_ref_base_pic_flag, and use_ref_base_pic_flag.
11 . A method for video encoding, comprising:
determining a layer structure comprising at least one layer having a first layer_id;
encoding a representation of the layer structure in a table of layers, the table of layers comprising layer descriptions comprising at least one property of the layer; and
encoding at least one NAL unit comprising a second layer_id;
wherein the second layer_id is the same as the first layer_id.
12 . The method of claim 11 , wherein the at least one property comprises at least one of: a dependency_id, a quality_id, a temporal_id, a view id, a depth_map_flag, and a dependent_flag.
13 . The method of claim 11 , wherein the NAL unit header further comprises a temporal_id.
14 . The method of claim 13 , wherein the temporal_id identifies a temporal sub-layer of a layer identified by the layer_id.
15 . The method of claim 11 , wherein the table of layer descriptions is part of a dependency parameter set.
16 . The method of claim 12 , wherein the depth_map_flag indicates that the first layer the NAL unit belongs to is a depth map, and is associated with a second layer identified by having the same view_id as the first layer.
17 . The method of claim 11 , wherein a predefined value for the second layer_id identifies the presence of extension data.
18 . The method of claim 11 , wherein the first layer_id is an indication of a position of the layer in a layer hierarchy.
19 . The method of claim 11 , wherein the NAL unit header further comprises at least one of: a store_ref_base_pic_flag and a use_ref_base_pic_flag.
20 . The method of claim 11 , wherein the NAL unit header is a slice NAL unit header, and the slice header of the slice carried in the NAL unit comprises at least one of a store_ref_base_pic_flag, and use_ref_base_pic_flag.
21 . A method for removing NAL units from a scalable bitstream, comprising:
receiving and decoding a table of layer descriptions comprising at least one layer description comprising at least one first layer_id;
receiving a slice NAL unit comprising a NAL unit header comprising a second layer_id;
removing the slice NAL unit only if the second layer_id identifies it as belonging to a layer to be removed.
22 . The method of claim 21 , wherein, the table of layer descriptions comprises a plurality of layer descriptions each having a layer_id, wherein no first layer described by a first layer description is depending on a second layer described by a second layer description, and wherein the layer_id of the first layer description is numerically lower than the layer_id of the second layer description.
23 . The method of claim 21 , wherein, the table of layer descriptions comprises a plurality of layer descriptions each having a layer_id, wherein no first layer described by a first layer description is depending on a second layer described by a second layer description, and wherein the layer_id of the first layer description is numerically higher than the layer_id of the second layer description.
24 . The method of claim 22 , further comprising:
after the removing of at least one NAL unit with a first layer_id, removing at least one NAL unit of a layer with a second layer_id; and
wherein the second layer_id is numerically lower than the first layer_id.
25 . The method of claim 23 , further comprising:
after the removing of at least one NAL unit with a first layer_id, removing at least one NAL unit of a layer with a second layer_id; and
wherein the second layer_id is numerically higher than the first layer_id.
26 . Non-transitory computer readable media comprising a set of instructions to perform the methods in one of claims 1 to 25 .