Extended motion information comparison
In some coding modes, such as the merge mode, a list of motion candidates is generated using spatial or temporal neighboring blocks or constructed ones, and one of the motion candidates is inherited by the current block. When constructing the list of motion candidates, motion information of a candidate to be added is checked to limit the redundancy in the constructed list. In one implementation, the switchable interpolation filter, the IFindex becomes part of the motion information to be used in comparison since it can modify the resulting prediction. Furthermore, the GBiIdx indicating the weights used in bi-prediction can also be part of the motion information to be compared and could also be taken into account in the redundancy check. In general, all or part of motion information that causes different prediction can be used in redundancy check.
1. A method of video encoding or decoding, comprising:
accessing a list of motion candidates for a block;
accessing motion information of a neighboring block of said block, said motion information including at least interpolation filter information and information indicating weights used in generalized bi-prediction, wherein said block is larger than 4×4 and said information indicating weights used in generalized bi-prediction is stored at a 4×4 level for all inter coding modes;
comparing said motion information of said neighboring block with motion information of a motion candidate in said list of motion candidates, wherein said comparison considers said interpolation filter information and said information indicating weights used in generalized bi-prediction, wherein a single memory comparison of a complete structure of motion information is used when comparing motion information;
responsive to said motion information of said neighboring block being different from said motion information of said motion candidate in said list of motion candidates, adding said neighboring block as a candidate to said list of motion candidates; and
encoding or decoding motion information of said block based on said list of motion candidates.
2. The method of claim 1 , wherein said neighboring block is considered redundant with said motion candidate when predictions corresponding to said motion information of said neighboring block and said motion information of said motion candidate are identical.
3. The method of claim 1 , wherein said list of motion candidates is used in a merge mode for signaling the motion information for said block.
4. The method of claim 1 , wherein said motion information for said block is signaled through an index into said list of motion candidates.
5. The method of claim 1 , wherein said list of motion candidates is used by all merge modes.
6. An apparatus for video encoding or decoding, comprising one or more processors, wherein said one or more processors are configured to:
access a list of motion candidates for a block;
access motion information of a neighboring block of said block, said motion information including at least interpolation filter information and information indicating weights used in generalized bi-prediction, wherein said block is larger than 4×4 and said information indicating weights used in generalized bi-prediction is stored at a 4×4 level for all inter coding modes;
compare said motion information of said neighboring block with motion information of a motion candidate in said list of motion candidates, wherein said comparison considers said interpolation filter information and said information indicating weights used in generalized bi-prediction, wherein a single memory comparison of a complete structure of motion information is used when comparing motion information;
responsive to said motion information of said neighboring block being different from said motion information of said motion candidate in said list of motion candidates, add said neighboring block as a candidate to said list of motion candidates; and
encode or decode motion information of said block based on said list of motion candidates.
7. The apparatus of claim 6 , wherein said neighboring block is considered redundant with said motion candidate when predictions corresponding to said motion information of said neighboring block and said motion information of said motion candidate are identical.
8. The apparatus of claim 6 , wherein said list of motion candidates is used in a merge mode for signaling the motion information for said block.
9. The apparatus of claim 6 , wherein said motion information for said block is signaled through an index into said list of motion candidates.
10. The apparatus of claim 6 , wherein said list of motion candidates is used by all merge modes.
11. A non-transitory computer-readable storage medium storing instructions when executed, implement an encoding or decoding method, the encoding or decoding method comprising:
accessing a list of motion candidates for a block;
accessing motion information of a neighboring block of said block, said motion information including at least interpolation filter information and information indicating weights used in generalized bi-prediction, wherein said block is larger than 4×4 and said information indicating weights used in generalized bi-prediction is stored at a 4×4 level for all inter coding modes;
comparing said motion information of said neighboring block with motion information of a motion candidate in said list of motion candidates, wherein said comparison considers said interpolation filter information and said information indicating weights used in generalized bi-prediction, wherein a single memory comparison of a complete structure of motion information is used when comparing motion information;
responsive to said motion information of said neighboring block being different from said motion information of said motion candidate in said list of motion candidates, adding said neighboring block as a candidate to said list of motion candidates; and
encoding or decoding motion information of said block based on said list of motion candidates.