Disabling inter-view prediction for reference picture list in video coding

1. A method for decoding video data, the method comprising:

obtaining, from a video parameter set (VPS) in a bitstream, a syntax element that indicates whether inter-view/layer reference pictures are ever included in a second reference picture list for any view component/layer representation of any coded video sequence (CVS) that refers to the VPS;

constructing, based on pictures in a reference picture set, a first reference picture list and a second reference picture list for a current view component/layer representation of a CVS that refers to the VPS, wherein at least one inter-view/layer reference picture is present in the first reference picture list for the current view component/layer representation; and

decoding the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, the current view component/layer representation is decoded without use of inter-view/layer reference pictures in the second reference picture list for the current view component/layer representation.

2. The method of claim 1 , wherein decoding the current view component/layer representation comprises:

performing a disparity vector derivation process that checks one or more blocks that neighbor a current block of the current view component/layer representation in order to determine a disparity vector for the current block, and

wherein performing the disparity vector derivation process comprises: when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any coded video sequence that refers to the VPS, not checking motion information corresponding to the second reference picture list for the current view component/layer representation.

3. The method of claim 1 , wherein the current view component/layer representation is in a particular layer in a plurality of layers in the bitstream, and the method comprises:

obtaining, for each respective layer from the plurality of layers, a respective syntax element for the respective layer, the respective syntax element indicating whether inter-view/layer reference pictures are ever included in respective second reference picture lists for view components/layer representations that are in the respective layer and that are in any CVS that refers to the VPS.

4. The method of claim 1 , further comprising obtaining, from the bitstream, reference picture list modification (RPLM) syntax elements for modifying the first reference picture list for the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, each of the RPLM syntax elements includes fewer bits than when the syntax element indicates that inter-view/layer reference pictures can be included in the second reference picture list for view component/layer representations of coded video sequences that refer to the VPS.

5. The method of claim 1 , wherein the syntax element is a first syntax element and the method further comprises obtaining, from the bitstream, a second syntax element, the second syntax element indicating a starting position of inter-view/layer reference pictures in the first reference picture list for the current view component/layer representation.

6. The method of claim 5 , wherein when the first syntax element indicates that inter-view/layer reference pictures can be included in the second reference picture lists for view component/layer representations of coded video sequences that refer to the VPS, obtaining, from the bitstream, a third syntax element, the third syntax element indicating a starting position of inter-view/layer reference pictures in the second reference picture list for the current view component/layer representation.

7. The method of claim 1 , wherein decoding the current view component/layer representation comprises:

performing a disparity vector derivation process that checks one or more blocks that neighbor a current block of the current view component/layer representation in order to determine a disparity vector for the current block,

wherein performing the disparity vector derivation process comprises: when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, storing at most one implicit disparity vector for each of the one or more blocks that neighbor the current block.

8. The method of claim 1 , wherein:

decoding the current view component/layer representation comprises:

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any coded video sequence that refers to the VPS, a candidate list does not include a candidate that corresponds to an inter-view/layer reference picture; and

determining, based on a particular candidate in the candidate list, a motion vector for a current block of the current view component/layer representation.

9. The method of claim 1 , further comprising:

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, avoiding checking of whether a reference picture from the second reference picture list of the current view component/layer representation is an inter-view/layer reference picture; and

when the syntax element indicates that inter-view/layer reference pictures are never included in the reference picture list for any view component/layer representation of any CVS that refers to the VPS, enabling, without checking a type of a particular reference picture in the second reference picture list for the current view component/layer representation, a residual predictor generation process for the second reference picture list for the current view component/layer representation if a prediction unit (PU) of a current coding unit (CU) of the current view component/layer representation has a motion vector that indicates a location in the particular reference picture.

10. The method of claim 1 , further comprising:

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, performing view synthesis prediction only using inter-view/layer reference pictures inserted into the first reference picture list for the current view component/layer representation; and

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, not considering an inter-view/layer reference picture set or inter-view/layer reference pictures when constructing an initial version of the second reference picture list for the current view component/layer representation.

11. A method of encoding video data, the method comprising:

constructing, based on pictures in a reference picture set, a first reference picture list and a second reference picture list for a current view component/layer representation, the current view component/layer representation belonging to a coded video sequence (CVS) that refers to a video parameter set (VPS), wherein at least one inter-view/layer reference picture is present in the first reference picture list for the current view component/layer representation;

signaling, in the VPS in a bitstream, a syntax element that indicates whether inter-view/layer reference pictures are ever included in a second reference picture list for any view component/layer representation of any CVS that refers to the VPS; and

encoding the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, the current view component/layer representation is not encoded using inter-view/layer reference pictures in the second reference picture list for the current view component/layer representation.

12. The method of claim 11 , wherein the current view component/layer representation is in a particular layer in a plurality of layers in the bitstream, and the method comprises:

signaling, in the VPS, for each respective layer from the plurality of layers, a respective syntax element for the respective layer, the respective syntax element indicating whether inter-view/layer reference pictures are ever included in respective second reference picture lists for view components/layer representations that are in the respective layer and that are in any CVS that refers to the VPS.

13. The method of claim 11 , further comprising signaling, in the bitstream, reference picture list modification (RPLM) syntax elements for modifying the second reference picture list for the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, each of the RPLM syntax elements includes fewer bits than when the syntax element indicates that inter-view/layer reference pictures can be included in the second reference picture lists for view component/layer representations of any CVS that refers to the VPS.

14. The method of claim 11 , wherein the syntax element is a first syntax element and the method further comprises signaling, in the bitstream, a second syntax element, the second syntax element indicating a starting position of inter-view/layer reference pictures in the first reference picture list for the current view component/layer representation.

15. A video decoding device comprising a non-transitory storage medium and one or more processors coupled to the storage medium, the one or more processors configured to:

obtain, from a video parameter set (VPS) in a bitstream, a syntax element that indicates whether inter-view/layer reference pictures are ever included in a second reference picture list for any view component/layer representation of any coded video sequence (CVS) that refers to the VPS;

construct, based on pictures in a reference picture set, a first reference picture list and a second reference picture list for a current view component/layer representation of a CVS that refers to the VPS, wherein at least one inter-view/layer reference picture is present in the first reference picture list for the current view component/layer representation; and

decode the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, the current view component/layer representation is decoded without use of inter-view/layer reference pictures in the second reference picture list for the current view component/layer representation.

16. The video decoding device of claim 15 , wherein the one or more processors are configured to:

perform a disparity vector derivation process that checks one or more blocks that neighbor a current block of the current view component/layer representation in order to determine a disparity vector for the current block, and

wherein the one or more processors are configured such that as part of performing the disparity vector derivation process, when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, the one or more processors do not check motion information corresponding to the second reference picture list for the current view component/layer representation.

17. The video decoding device of claim 15 , wherein the current view component/layer representation is in a particular layer in a plurality of layers in the bitstream, and the one or more processors are configured to:

obtain, for each respective layer from the plurality of layers, a respective syntax element for the respective layer, the respective syntax element indicating whether inter-view/layer reference pictures are ever included in respective second reference picture lists for view components/layer representations that are in the respective layer and that are in any CVS that refers to the VPS.

18. The video decoding device of claim 15 , wherein the one or more processors are further configured to obtain, from the bitstream, reference picture list modification (RPLM) syntax elements for modifying the second reference picture list for the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, each of the RPLM syntax elements includes fewer bits than when the syntax element indicates that inter-view/layer reference pictures can be included in the second reference picture lists for view component/layer representations of any coded video sequence that refers to the VPS.

19. The video decoding device of claim 15 , wherein the syntax element is a first syntax element and the one or more processors are configured to obtain, from the bitstream, a second syntax element, the second syntax element indicating a starting position of inter-view/layer reference pictures in the first reference picture list for the current view component/layer representation.

20. The video decoding device of claim 15 , wherein the one or more processors are configured to:

perform a disparity vector derivation process that checks one or more blocks that neighbor a current block of the current view component/layer representation in order to determine a disparity vector for the current block, and

wherein the one or more processors are configured such that, as part of performing the disparity vector derivation process, when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, the one or more processors store at most one implicit disparity vector for each of the one or more blocks that neighbor the current block.

21. The video decoding device of claim 15 , wherein the one or more processors are configured to:

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any coded video sequence that refers to the VPS, a candidate list does not include a candidate that corresponds to an inter-view/layer reference picture; and

determine, based on a particular candidate in the candidate list, a motion vector for a current block of the current view component/layer representation.

22. The video decoding device of claim 15 , wherein the one or more processors are configured to:

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, avoid checking of whether a reference picture from the second reference picture list for the current view component/layer representation is an inter-view/layer reference picture; and

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, enable, without checking a type of a particular reference picture in the second reference picture list for the current view component/layer representation, a residual predictor generation process for the second reference picture list for the current view component/layer representation if a prediction unit (PU) of a current coding unit (CU) of the current view component/layer representation has a motion vector that indicates a location in the particular reference picture.

23. The video decoding device of claim 15 , wherein the one or more processors are configured to:

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, perform view synthesis prediction only using inter-view/layer reference pictures inserted into the first reference picture list for the current view component/layer representation; and

when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, not consider an inter-view/layer reference picture set or inter-view/layer reference pictures when constructing an initial version of the second reference picture list for the current view component/layer representation.

24. The video decoding device of claim 15 , wherein the video decoding device comprises at least one of:

an integrated circuit; and

a microprocessor.

25. A video decoding device comprising:

means for obtaining, from a video parameter set (VPS) in a bitstream, a syntax element that indicates whether inter-view/layer reference pictures are ever included in a second reference picture list for any view component/layer representation of any coded video sequence (CVS) that refers to the VPS;

means for constructing, based on pictures in a reference picture set, a first reference picture list and a second reference picture list for a current view component/layer representation of a CVS that refers to the VPS, wherein at least one inter-view/layer reference picture is present in the first reference picture list for the current view component/layer representation; and

means for decoding the current view component/layer representation, wherein when the syntax element indicates that inter-view/layer reference pictures are never included in the second reference picture list for any view component/layer representation of any CVS that refers to the VPS, the current view component/layer representation is decoded without use of inter-view/layer reference pictures in the second reference picture list for the current view component/layer representation.