Method and apparatus for deriving temporal motion vector prediction

1. A method of deriving a motion vector predictor (MVP) for a motion vector (MV) of a current block of a current picture in Inter, or Merge, or Skip mode, wherein the MV is associated with the current block and a corresponding block of a target reference picture in a given reference list, the method comprising:

selecting a co-located block corresponding to a co-located picture;

receiving one or more reference motion vectors (MVs) of one or more co-located reference blocks associated with the co-located block;

determining a search set, wherein the search set comprises one or more search MVs associated with said one or more co-located reference blocks;

determining a search order for the search set, wherein the search order associated with a reference list attribute for a first search MV and a second search MV associated with an identical co-located reference block and pointing to different reference lists, wherein the first search MV pointing to a target reference list has a higher search priority than the second search MV not pointing to the target reference list;

determining the MVP for the current block based on the search set and the search order; and

providing the MVP for the current block.

2. The method of claim 1 , wherein the target reference list is identical to the given reference list, and said determining the MVP for the current block searches the first search MV associated with one of said one or more co-located reference blocks and pointing to the given reference list before searches the second search MV associated with said one of said one or more co-located reference blocks and not pointing to the given reference list.

3. The method of claim 1 , wherein the co-located picture associated with the co-located block is indicated by a flag, and information associated with the flag is incorporated in sequence level, picture level, or slice level.

4. The method of claim 1 , wherein the co-located picture associated with the co-located block is derived according to an implicit method or an explicit method as indicated by a flag.

5. The method of claim 1 , wherein said one or more co-located reference blocks comprise an inside co-located reference block and outside co-located reference block.

6. The method of claim 5 , wherein the inside co-located reference block is located at center of the co-located block.

7. The method of claim 5 , wherein the outside co-located reference block is located outside the co-located block across from a lower-right corner of the co-located block.

8. The method of claim 1 , wherein the search order further associated with a block position attribute for a first co-located reference block outside the co-located block and a second co-located reference block inside the co-located block, wherein search MVs associated with the first co-located reference block have a higher search priority than search MVs associated with the second co-located reference block.

9. The method of claim 8 , said determining the MVP for the current block sequentially searches the first search MV associated with the first co-located reference block and pointing to the target reference list, the second search MV associated with the first co-located reference block and not pointing to the target reference list, the first search MV associated with the second co-located reference block and pointing to the target reference list, and the second search MV associated with the second co-located reference block and not pointing to the target reference list.

10. The method of claim 8 , said determining the MVP for the current block sequentially searches the first search MV associated with the first co-located reference block and pointing to the target reference list, the first search MV associated with the second co-located reference block and pointing to the target reference list, the second search MV associated with the first co-located reference block and not pointing to the target reference list, and the second search MV associated with the second co-located reference block and not pointing to the target reference list.

11. An apparatus for deriving a motion vector predictor (MVP) for a motion vector (MV) of a current block of a current picture in Inter, or Merge, or Skip mode, wherein the MV is associated with the current block and a corresponding block of a target reference picture in a given reference list, the apparatus comprising at least one circuit configured for:

selecting a co-located block corresponding to a co-located picture;

receiving one or more reference motion vectors (MVs) of one or more co-located reference blocks associated with the co-located block;

determining a search set, wherein the search set comprises one or more search MVs associated with said one or more co-located reference blocks;

determining a search order for the search set, wherein the search order associated with a reference list attribute for a first search MV and a second search MV associated with an identical co-located reference block and pointing to different reference lists, wherein the first search MV pointing to a target reference list has a higher search priority than the second search MV not pointing to the target reference list;

determining the MVP for the current block based on the search set and the search order; and

providing the MVP for the current block.

12. The apparatus of claim 11 , wherein the target reference list is identical to the given reference list, and said determining the MVP for the current block searches the first search MV associated with one of said one or more co-located reference blocks and pointing to the given reference list before searches the second search MV associated with said one of said one or more co-located reference blocks and not pointing to the given reference list.

13. The apparatus of claim 11 , wherein the co-located picture associated with the co-located block is indicated by a flag, and information associated with the flag is incorporated in sequence level, picture level, or slice level.

14. The apparatus of claim 11 , wherein the co-located picture associated with the co-located block is derived according to an implicit method or an explicit method as indicated by a flag.

15. The apparatus of claim 11 , wherein said one or more co-located reference blocks comprise an inside co-located reference block and outside co-located reference block.

16. The apparatus of claim 15 , wherein the inside co-located reference block is located at center of the co-located block.

17. The apparatus of claim 15 , wherein the outside co-located reference block is located outside the co-located block across from a lower-right corner of the co-located block.

18. The apparatus of claim 11 , wherein the search order further associated with a block position attribute for a first co-located reference block outside the co-located block and a second co-located reference block inside the co-located block, wherein search MVs associated with the first co-located reference block have a higher search priority than search MVs associated with the second co-located reference block.

19. The method of claim 18 , said determining the MVP for the current block sequentially searches the first search MV associated with the first co-located reference block and pointing to the target reference list, the second search MV associated with the first co-located reference block and not pointing to the target reference list, the first search MV associated with the second co-located reference block and pointing to the target reference list, and the second search MV associated with the second co-located reference block and not pointing to the target reference list.

20. The method of claim 18 , said determining the MVP for the current block sequentially searches the first search MV associated with the first co-located reference block and pointing to the target reference list, the first search MV associated with the second co-located reference block and pointing to the target reference list, the second search MV associated with the first co-located reference block and not pointing to the target reference list, and the second search MV associated with the second co-located reference block and not pointing to the target reference list.