Method and apparatus for video coding

1. A method for video decoding in a decoder, comprising:

decoding coded information for a current block from a coded video bitstream, the coded information indicating a bi-prediction motion compensation mode for the current block;

ranking, based on current neighboring reconstructed samples of the current block, first neighboring reconstructed samples of a first prediction block, and second neighboring reconstructed samples of a second prediction block, plural pre-defined weights used in the bi-prediction motion compensation mode;

selecting one of the plural pre-defined weights based on an index included in the coded information; and

reconstructing samples in the current block based on a weighted average of corresponding samples in the first prediction block and the second prediction block using the selected weight.

2. The method of claim 1 , wherein the pre-defined weights are stored in the decoder.

3. The method of claim 2 , wherein

the decoding further includes decoding the index in the coded information;

each of the ranked pre-defined weights being associated with a unique ranking index, the decoded index corresponding to one of the ranking indices; and

the selected weight is one of the ranked pre-defined weights that is associated with the one of the ranking indices.

4. The method of claim 1 , wherein the current neighboring reconstructed samples of the current block, the first neighboring reconstructed samples of the first prediction block, and the second neighboring reconstructed samples of the second prediction block are spatial neighboring reconstructed samples of the current block, the first prediction block, and the second prediction block, respectively.

5. The method of claim 1 , wherein the first prediction block is in a first reference picture, and the second prediction block is in a second reference picture that is different from the first reference picture.

6. A non-transitory computer-readable storage medium storing a program executable by at least one processor of a decoder to perform:

decoding coded information for a current block from a coded video bitstream, the coded information indicating a bi-prediction motion compensation mode for the current block;

ranking, based on current neighboring reconstructed samples of the current block, first neighboring reconstructed samples of a first prediction block, and second neighboring reconstructed samples of a second prediction block, plural pre-defined weights used in the bi-prediction motion compensation mode;

selecting one of the plural pre-defined weights based on an index included in the coded information; and

reconstructing samples in the current block based on a weighted average of corresponding samples in the first prediction block and the second prediction block using the selected weight.

7. The non-transitory computer-readable storage medium of claim 6 , wherein the pre-defined weights are stored in the decoder.

8. The non-transitory computer-readable storage medium of claim 7 , wherein

the decoding further includes decoding the index in the coded information;

each of the ranked pre-defined weights being associated with a unique ranking index, the decoded index corresponding to one of the ranking indices; and

the selected weight is one of the ranked pre-defined weights that is associated with the one of the ranking indices.

9. The non-transitory computer-readable storage medium of claim 6 , wherein the current neighboring reconstructed samples of the current block, the first neighboring reconstructed samples of the first prediction block, and the second neighboring reconstructed samples of the second prediction block are spatial neighboring reconstructed samples of the current block, the first prediction block, and the second prediction block, respectively.

10. A decoder apparatus for video decoding, comprising:

processing circuitry configured to:

decode coded information for a current block from a coded video bitstream, the coded information indicating a bi-prediction motion compensation mode for the current block;

rank, based on current neighboring reconstructed samples of the current block, first neighboring reconstructed samples of a first prediction block, and second neighboring reconstructed samples of a second prediction block, plural pre-defined weights used in the bi-prediction motion compensation mode;

select one of the plural pre-defined weights based on an index included in the coded information; and

reconstruct samples in the current block based on a weighted average of corresponding samples in the first prediction block and the second prediction block using the selected weight.

11. The apparatus of claim 10 , wherein the pre-defined weights are stored in the decoder apparatus.

12. The apparatus of claim 11 , wherein the processing circuitry is configured to:

decode the index in the coded information; wherein

each of the ranked pre-defined weights being associated with a unique ranking index, the decoded index corresponding to one of the ranking indices; and

the selected weight is one of the ranked pre-defined weights that is associated with the one of the ranking indices.

13. The apparatus of claim 10 , wherein the current neighboring reconstructed samples of the current block, the first neighboring reconstructed samples of the first prediction block, and the second neighboring reconstructed samples of the second prediction block are spatial neighboring reconstructed samples of the current block, the first prediction block, and the second prediction block, respectively.

14. The apparatus of claim 10 , wherein the first prediction block is in a first reference picture, and the second prediction block is in a second reference picture that is different from the first reference picture.