Method and apparatus for processing video signal
The present invention relates to a method and apparatus for processing a video signal, which can increase the accuracy of the motion vector prediction through motion vector scaling which takes a difference in the temporal distance between reference pictures into consideration. To this end, the present invention provides a video signal processing method and a video signal processing apparatus using the same, and the method comprises the steps of: scaling at least one neighboring partition motion vector for a motion vector prediction of the current partition; scaling the neighboring partition motion vector, which has been selected, when the reference picture of the neighboring partition motion vector is different from the reference picture of the current partition; acquiring a motion vector prediction value of the current partition using the scaled motion vector; and acquiring a motion vector of the current partition using the motion vector prediction value.
1. A method of processing a video signal, the method comprising:
obtaining index information from the video signal, the index information specifying a motion vector candidate to be used as a motion vector predictor of a current block;
deriving at least one spatial motion vector candidate from at least one neighboring block of the current block;
constructing a motion vector candidate group of the current block, the motion vector candidate group comprising a plurality of motion vector candidates including the derived at least one spatial motion vector candidate;
assigning a motion vector candidate specified by the index information from among the motion vector candidate group to the motion vector predictor of the current block; and
decoding the current block based on the motion vector predictor,
wherein the deriving the at least one spatial motion vector candidate includes:
assigning a motion vector of the at least one neighboring block to the at least one spatial motion vector candidate when a reference picture list for the at least one neighboring block is different from a reference picture list for the current block and a reference picture of the at least one neighboring block is same as a reference picture of the current block based on picture order count (POC) information.
2. The method of claim 1 , wherein the deriving the at least one spatial motion vector candidate further includes:
assigning the motion vector of the at least one neighboring block to the at least one spatial motion vector candidate when the reference picture list for the at least one neighboring block is same as the reference picture list for the current block and the reference picture of the at least one neighboring block is same as the reference picture of the current block based on the POC information.
3. The method of claim 1 , wherein the deriving the at least one spatial motion vector candidate further includes:
assigning the motion vector of the at least one neighboring block to the at least one spatial motion vector candidate based on the reference picture of the at least one neighboring block being different from the reference picture of the current block.
4. The method of claim 3 , wherein the deriving the at least one spatial motion vector candidate further includes:
scaling the at least one spatial motion vector candidate using a temporal distance between the reference picture of the at least one neighboring block and the reference picture of the current block when the reference picture of the at least one neighboring block is different from the reference picture of the current block.
5. The method of claim 1 , wherein the at least one neighboring block includes at least one of a bottom left neighboring block of the current block or a left neighboring block of the current block.
6. The method of claim 1 , wherein the at least one neighboring block includes at least one of a top right neighboring block of the current block, a top neighboring block of the current block, or a top left neighboring block of the current block.
7. The method of claim 1 , further comprising:
deriving a temporal motion vector candidate from a co-located block of the current block, the co-located block being located in a position corresponding to the current block in a picture different from a picture including the current block,
wherein the motion vector candidate group further comprises the derived temporal motion vector candidate.
8. The method of claim 1 , wherein the POC information represents a number assigned to a picture according to a temporal order of the picture.
9. An apparatus for processing a video signal, the apparatus comprising:
a memory; and
a processor operatively connected to the memory and configured to:
obtain index information from the video signal, the index information specifying a motion vector candidate to be used as a motion vector predictor of a current block,
derive at least one spatial motion vector candidate from at least one neighboring block of the current block,
construct a motion vector candidate group of the current block, the motion vector candidate group comprising a plurality of motion vector candidates including the derived at least one spatial motion vector candidate,
assign a motion vector candidate specified by the index information from among the motion vector candidate group to the motion vector predictor of the current block, and
decode the current block based on the motion vector predictor,
wherein the deriving the at least one spatial motion vector candidate includes:
assigning a motion vector of the at least one neighboring block to the at least one spatial motion vector candidate when a reference picture list for the at least one neighboring block is different from a reference picture list for the current block and a reference picture of the at least one neighboring block is same as a reference picture of the current block based on picture order count (POC) information.
10. The apparatus of claim 9 , wherein the deriving the at least one spatial motion vector candidate further includes:
assigning the motion vector of the at least one neighboring block to the at least one spatial motion vector candidate when the reference picture list for the at least one neighboring block is same as the reference picture list for the current block and the reference picture of the at least one neighboring block is same as the reference picture of the current block based on the POC information.
11. The apparatus of claim 9 , wherein the deriving the at least one spatial motion vector candidate further includes:
assigning the motion vector of the at least one neighboring block to the at least one spatial motion vector candidate based on the reference picture of the at least one neighboring block being different from the reference picture of the current block.
12. The apparatus of claim 11 , wherein the deriving the at least one spatial motion vector candidate further includes:
scaling the at least one spatial motion vector candidate using a temporal distance between the reference picture of the at least one neighboring block and the reference picture of the current block when the reference picture of the at least one neighboring block is different from the reference picture of the current block.
13. The apparatus of claim 11 , wherein the at least one neighboring block includes at least one of a bottom left neighboring block of the current block or a left neighboring block of the current block.
14. The apparatus of claim 11 , wherein the at least one neighboring block includes at least one of a top right neighboring block of the current block, a top neighboring block of the current block, or a top left neighboring block of the current block.
15. The apparatus of claim 11 , wherein the processor is further configured to:
derive a temporal motion vector candidate from a co-located block of the current block, the co-located block being located in a position corresponding to the current block in a picture different from a picture including the current block,
wherein the motion vector candidate group further comprises the derived temporal motion vector candidate.
16. The apparatus of claim 11 , wherein the POC information represents a number assigned to a picture according to a temporal order of the picture.