Signaling of inter layer prediction in video bitstream

1 . A method for video decoding performed by at least one processor, the method comprising:

receiving a scalable bitstream including a first layer;

determining whether the first layer is a dependent layer of the scalable bitstream based at least in part on a syntax element from the scalable bitstream;

when the first layer is the dependent layer, decoding a picture in the dependent layer based on an inter-layer reference picture (ILRP) list, wherein a size of the ILRP corresponds to a number of direct reference layers indicated in the scalable bitstream; and

when the first layer is not the dependent layer, decoding the picture in the first layer without using the ILRP list.

2 . The method of claim 1 , further comprising decoding a second picture that is in an independent layer by parsing and interpreting a reference picture list which does not include any decoded picture of another layer.

3 . The method of claim 1 , wherein the ILRP list includes a decoded picture of a different layer.

4 . The method of claim 1 , further comprising determining whether another syntax element indicates a maximum number of layers.

5 . The method of claim 1 , further comprising determining whether a parameter set of the scalable bitstream comprises a flag indicating whether a different layer in the scalable bitstream is a reference layer for at least one layer.

6 . The method of claim 5 , further comprising:

determining whether the flag indicates the different layer as the reference layer for the at least one layer by specifying an index of the different layer and an index of the at least one layer, and

determining whether the parameter set comprises another syntax element indicating a value less than a determined number of dependent layers.

7 . The method of claim 5 , further comprising:

determining whether the flag indicates the different layer as not being the reference layer for the at least one layer by specifying an index of the different layer and an index of the at least one layer, and

determining whether the parameter set comprises another syntax element indicating a value less than a determined number of dependent layers.

8 . The method of claim 1 , further comprising determining whether a parameter set of the scalable bitstream comprises a flag indicating whether a plurality of layers are to be decoded by interpreting the ILRP list.

9 . The method of claim 1 , further comprising determining whether a parameter set of the scalable bitstream comprises a flag indicating whether a plurality of layers are to be decoded without interpreting the ILRP list.

10 . The method of claim 1 , wherein the ILRP list is signaled with an inter-prediction reference picture (IPRP) list in the scalable bitstream.

11 . A computing system, comprising:

control circuitry;

memory; and

one or more sets of instructions stored in the memory and configured for execution by the control circuitry, the one or more sets of instructions comprising instructions for:

receiving video data;

for a first layer of the video data:

generating a syntax element indicating whether the first layer is a dependent layer;

when the first layer is the dependent layer, encoding a picture in the first layer using an inter-layer reference picture (ILRP) list, wherein a size of the ILRP corresponds to a number of direct reference layers in the video data; and

when the first layer is not the dependent layer, encoding the picture in the first layer without using the ILRP list; and

transmitting a scalable bitstream that includes the encoded picture and the syntax element.

12 . The computing system of claim 11 , wherein the one or more sets of instructions further comprise instructions for encoding a second picture that is in an independent layer without using a picture of a different layer.

13 . The computing system of claim 11 , wherein the ILRP includes a picture of a different layer.

14 . The computing system of claim 11 , wherein the one or more sets of instructions further comprise instructions for generating a second syntax element indicating whether a different layer is a reference layer for at least one layer.

15 . The computing system of claim 11 , wherein the ILRP list is signaled with an inter-prediction reference picture (IPRP) list in the scalable bitstream.

16 . A non-transitory computer-readable storage medium storing one or more instructions and a video bitstream that is generated by a video encoding method, the one or more instructions when executed by a processor, cause a computing system to perform the video encoding method, wherein the video bitstream comprises coded information for a plurality of pictures of video data, including a first picture in a first layer of the video data, and a syntax element indicating whether the first layer of the video data is a dependent layer, and the video encoding method comprises, for the first layer of video data:

generating the syntax element;

when the first layer is the dependent layer, encoding the first picture in the first layer using an inter-layer reference picture (ILRP) list, wherein a size of the ILRP corresponds to a number of direct reference layers in the video data; and

when the first layer is not the dependent layer, encoding the first picture in the first layer without using the ILRP list.

17 . The non-transitory computer-readable storage medium of claim 16 , wherein the video bitstream further comprises an encoded second picture in the independent layer, and wherein the encoded second picture is encoded without using a picture of a different layer.

18 . The non-transitory computer-readable storage medium of claim 16 , wherein the ILRP includes a picture of a different layer.

19 . The non-transitory computer-readable storage medium of claim 16 , wherein the video bitstream further comprises a second syntax element indicating whether a different layer in the video bitstream is a reference layer for at least one layer.

20 . The non-transitory computer-readable storage medium of claim 16 , wherein the ILRP list is signaled with an inter-prediction reference picture (IPRP) list in the video bitstream.