Temporal motion data candidate derivation in video coding

1. A method for derivation of a temporal motion data (TMD) candidate for a prediction unit (PU) in video encoding or video decoding, the TMD candidate for inclusion in an inter-prediction candidate list for the PU, the method comprising:

determining a primary TMD position relative to a co-located PU, wherein the co-located PU is a block in a reference picture having a same size, shape, and coordinates as the PU;

selecting at least some motion data of a secondary TMD position as the TMD candidate when the primary TMD position is in a bottom neighboring PU or in a bottom right neighboring PU relative to the prediction unit, wherein the secondary TMD position is determined relative to the co-located PU and constrained to be within boundaries of a coding unit row containing the PU.

2. The method of claim 1 , further comprising:

determining an alternative TMD position relative to the co-located PU when the primary TMD position is in the bottom neighboring PU or in the bottom right neighboring PU; and

selecting at least some motion data of the alternative TMD position as the TMD candidate when the motion data of the alternative TMD position is available,

wherein selecting at least some motion data of a secondary TMD position comprises selecting at least some of the motion data of the secondary TMD position as the TMD candidate when the primary TMD position is in the bottom neighboring PU or in the bottom right neighboring PU when the motion data of the alternative TMD position is not available.

3. The method of claim 1 , wherein the primary TMD position is a bottom right neighboring position outside the co-located PU, and the secondary TMD position is inside the co-located PU.

4. The method of claim 3 , wherein the secondary TMD position is one selected from an upper left central position inside the co-located PU and a bottom right central position inside the co-located PU.

5. The method of claim 2 , wherein the primary TMD position is a bottom right neighboring position outside the co-located PU, the secondary TMD position is inside the co-located PU, and the alternative TMD position is one selected from a bottom right neighboring position outside the co-located PU and inside the co-located LCU row and a bottom right position inside the co-located PU.

6. The method of claim 1 , wherein the TMD candidate is one selected from a group consisting of a temporal merging candidate and a temporal motion vector predictor (MVP) candidate.

7. A method for derivation of a temporal merging candidate for a prediction unit (PU) video encoding or video decoding, the temporal merging candidate for inclusion in a merging candidate list for the PU, the method comprising:

determining a primary temporal motion data (TMD) position relative to a co-located PU, wherein the co-located PU is a block in a reference picture having a same size, shape, and coordinates as the PU and the primary TMD position is a bottom right neighboring position outside the co-located PU and constrained to be located in a coding unit row containing the PU; and

selecting motion data of a secondary TMD position as the temporal merging candidate when the primary TMD position is in a bottom neighboring PU or in a bottom right neighboring PU, wherein the secondary TMD position is inside the co-located PU and constrained to be within boundaries of a coding unit row containing the PU.

8. The method of claim 7 , further comprising:

determining an alternative TMD position relative to the co-located PU when the primary TMD position is in the bottom neighboring PU or in the bottom right neighboring PU, wherein the alternative TMD position is one selected from a bottom right neighboring position outside the co-located PU and inside a coding unit row containing the PU and a bottom right position relative to the co-located PU; and

selecting motion data of the alternative TMD position as the temporal merging candidate when the motion data of the alternative TMD position is available,

wherein selecting motion data of a secondary TMD position comprises selecting the motion data of the secondary TMD position as the temporal merging candidate when the primary TMD position is in the bottom neighboring PU or in the bottom right neighboring PU of the co-located PU and when the motion data of the alternative TMD position is not available.

9. The method of claim 7 , wherein the secondary TMD position is one selected from an upper left central position inside the co-located PU and a bottom right central position inside the co-located PU.

10. A method for derivation of a temporal motion vector predictor (MVP) candidate for a prediction unit (PU) in video encoding or video decoding, the temporal MVP candidate for inclusion in an advanced MVP (AMVP) candidate list for the PUT, the method comprising:

determining a primary temporal motion data (TMD) position relative to a co-located PU in a coding unit, wherein the co-located PU is a block in a reference picture having a same size, shape, and coordinates as the PU and the primary TMD position is a bottom right neighboring position outside the co-located PU and constrained to be located in a coding unit row containing the PU; and

selecting motion vector data from motion data of a secondary TMD position as the temporal MVP candidate when the primary TMD position is in a bottom neighboring PU or in a bottom right neighboring PU of the co-located PU, wherein the secondary TMD position is inside the co-located PU and constrained to be within boundaries of a coding unit row containing the PU.

11. The method of claim 10 , further comprising:

determining an alternative TMD position relative to the co-located PU when the primary TMD position is in the bottom neighboring PU or in the bottom right neighboring PU, wherein the alternative TMD position is one selected from a bottom right neighboring position outside the co-located PU and a bottom right position inside the co-located PU; and

selecting motion data of the alternative TMD position as the temporal MVP candidate when the motion data of the alternative TMD position is available,

wherein selecting motion data of a secondary TMD position comprises selecting the motion data of the secondary TMD position as the temporal MVP candidate when the primary TMD position is in the bottom neighboring PU or in the bottom right neighboring PU of the co-located PU and when the motion data of the alternative TMD position is not available.

12. The method of claim 10 , wherein the secondary TMD position is one selected from an upper left central position inside the co-located PU and a bottom right central position inside the co-located PU.