Combined motion vector and reference index prediction for video coding

1. A method for encoding an image, comprising:

selecting a plurality of motion vector predictors of a current image block based at least in part on at least one of a coding mode of a block from which the respective motion vector predictor is derived and a reference index of the block from which the respective motion vector predictor is derived, wherein the blocks having a coding mode of intra or not available are excluded from the plurality of motion vector predictors;

selecting two candidate motion vector predictors from the plurality of motion vector predictors, wherein the two candidate motion vector predictors each have a distinct value;

selecting a particular motion vector predictor of the current image block from the two candidate motion vector predictors; and

providing in an encoded bitstream a flag representative of the selected motion vector predictor, wherein the flag value of 0 indicates the selection of the first candidate, while the flag value of 1 indicates the selection of the second candidate.

2. The method of claim 1 , further comprising:

adding a zero motion vector to the candidate motion vector predictors, when the candidate list is empty.

3. The method of claim 1 , wherein the coding mode indicates partitioning information for the block from which the respective motion vector predictor is derived.

4. The method of claim 3 , wherein the partitioning information represents the size and the shape of the block from which the respective motion vector predictor is derived.

5. The method of claim 1 , wherein the plurality of motion vector predictors comprise at least one motion vector for blocks selected from the group consisting of a neighboring block of the current image block, a block in a second image, a co-located block in the second image, a neighboring block of the co-located block in the second image, a block in a second layer and a block in a second view.

6. The method of claim 1 , wherein an additional motion vector predictor is added to the plurality of motion vector predictors if a value of the additional motion vector predictor is not represented by the plurality of motion vector predictors.

7. The method of claim 1 , further comprising:

using the reference index associated with the selected motion vector predictor as a reference index for the current image block.

8. A computer program product, embodied on a non-transitory machine readable medium, for causing a machine, when executed, to perform the process of claim 1 .

9. An apparatus, comprising:

a processor; and

a memory communicatively connected to the processor and including computer code configured to:

select a plurality of motion vector predictors of a current image block based at least in part on at least one of a coding mode of a block from which the respective motion vector predictor is derived and a reference index of the block from which the respective motion vector predictor is derived, wherein the blocks having a coding mode of intra or not available are excluded from the plurality of motion vector predictors;

select two candidate motion vector predictors from the plurality of motion vector predictors, wherein the two candidate motion vector predictors each have a distinct value; select a particular motion vector predictor of the current image block from the two candidate motion vector predictors; and

provide in an encoded bitstream a flag representative of the selected motion vector predictor, wherein the flag value of 0 indicates the selection of the first candidate, while the flag value of 1 indicates the selection of the second candidate.

10. The apparatus of claim 9 , wherein the apparatus is further configured:

add a zero motion vector to the candidate motion vector predictors, when the candidate list is empty.

11. The apparatus of claim 9 , wherein the coding mode indicates partitioning information for the block from which the respective motion vector predictor is derived.

12. The apparatus of claim 11 , wherein the partitioning information represents the size and the shape of the block from which the respective motion vector predictor is derived.

13. The apparatus of claim 9 , wherein the plurality of motion vector predictors comprise at least one motion vector for blocks selected from the group consisting of a neighboring block of the current image block, a block in a second image, a co-located block in the second image, a neighboring block of the co-located block in the second image, a block in a second layer and a block in a second view.

14. The apparatus of claim 9 , wherein an additional motion vector predictor is added to the plurality of motion vector predictors if a value of the additional motion vector predictor is not represented by the plurality of motion vector predictors.

15. The apparatus of claim 9 , wherein the apparatus is further configured to use the reference index associated with the selected motion vector predictor as a reference index for the current image block.

16. An apparatus, comprising:

means for selecting a plurality of motion vector predictors of a current image block based at least in part on at least one of a coding mode of a block from which the respective motion vector predictor is derived and a reference index of the block from which the respective motion vector predictor is derived, wherein the blocks having a coding mode of intra or not available are excluded from the plurality of motion vector predictors;

means for selecting two candidate motion vector predictors from the plurality of motion vector predictors, wherein the two candidate motion vector predictors each have a distinct value; means for selecting a particular motion vector predictor of the current image block from the two candidate motion vector predictors; and

means for providing in an encoded bitstream a flag representative of the selected motion vector predictor, wherein the flag value of 0 indicates the selection of the first candidate, while the flag value of 1 indicates the selection of the second candidate.

17. A method for decoding an image, comprising:

selecting a plurality of motion vector predictors of a current image block based at least in part on at least one of a coding mode of a block from which the respective motion vector predictor is derived and a reference index of the block from which the respective motion vector predictor is derived, wherein the blocks having a coding mode of intra or not available are excluded from the plurality of motion vector predictors;

selecting two candidate motion vector predictors from the plurality of motion vector predictors, wherein the two candidate motion vector predictors each have a distinct value; receiving from an encoded bitstream a flag representative of a selected motion vector predictor; and

selecting a particular motion vector predictor of the current image block from the two candidate motion vector predictors for use in decoding based on the received flag, wherein the flag value of 0 indicates the selection of the first candidate, while the flag value of 1 indicates the selection of the second candidate.

18. The method of claim 17 , further comprising:

adding zero motion vector to the candidate motion vector predictors, when the candidate list is empty.

19. The method of claim 17 , wherein the coding mode indicates partitioning information for the block from which the respective motion vector predictor is derived.

20. The method of claim 19 , wherein the partitioning information represents a size and a shape of the block from which the respective motion vector predictor is derived.

21. The method of claim 17 , wherein the plurality of motion vector predictors comprise at least one motion vector for blocks selected from the group consisting of a neighboring block of the current image block, a block in a second image, a co-located block in the second image, a neighboring block of the co-located block in the second image, a block in a second layer and a block in a second view.

22. The method of claim 17 , further comprising:

using the reference index associated with the selected motion vector predictor as a reference index for the current image block.

23. A computer program product, embodied on a non-transitory machine readable medium, for causing a machine, when executed, to perform the process of claim 17 .

24. An apparatus, comprising:

a processor; and

a memory communicatively connected to the processor and including computer code configured to:

select a plurality of motion vector predictors of a current image block based at least in part on at least one of a coding mode of a block from which the respective motion vector predictor is derived and a reference index of the block from which the respective motion vector predictor is derived, wherein the blocks having a coding mode of intra or not available are excluded from the plurality of motion vector predictors;

select two candidate motion vector predictors from the plurality of motion vector predictors, wherein the two candidate motion vector predictors each have a distinct value;

receive from an encoded bitstream a flag representative of a selected motion vector predictor; and

select a particular motion vector predictor of the current image block from the two candidate motion vector predictors for use in decoding based on the received flag, wherein the flag value of 0 indicates the selection of the first candidate, while the flag value of 1 indicates the selection of the second candidate.

25. The apparatus of claim 24 , wherein the apparatus is further configured:

add a zero motion vector to the candidate motion vector predictors, when the candidate list is empty.

26. The apparatus of claim 24 , wherein the coding mode indicates partitioning information for the block from which the respective motion vector predictor is derived.

27. The apparatus of claim 26 , wherein the partitioning information represents a size and a shape of the block from which the respective motion vector predictor is derived.

28. The apparatus of claim 24 , wherein the plurality of motion vector predictors comprise at least one motion vector for blocks selected from the group consisting of a neighboring block of the current image block, a block in a second image, a co-located block in the second image, a neighboring block of the co-located block in the second image, a block in a second layer and a block in a second view.

29. The apparatus of claim 24 , wherein the apparatus is further configured to use the reference index associated with the selected motion vector predictor as a reference index for the current image block.

30. An apparatus, comprising:

means for selecting a plurality of motion vector predictors of a current image block based at least in part on at least one of a coding mode of a block from which the respective motion vector predictor is derived and a reference index of the block from which the respective motion vector predictor is derived, wherein the blocks having a coding mode of intra or not available are excluded from the plurality of motion vector predictors;

means for selecting two candidate motion vector predictors from the plurality of motion vector predictors, wherein the two candidate motion vector predictors each have a distinct value,

means for receiving from an encoded bitstream a flag representative of a selected motion vector predictor; and

means for selecting a particular motion vector predictor of the current image block from the two candidate motion vector predictors for use in decoding based on the received flag, wherein the flag value of 0 indicates the selection of the first candidate, while the flag value of 1 indicates the selection of the second candidate.