Method and apparatus for processing video signals on basis of inter prediction
A method for processing video signals on the basis of inter prediction includes the steps of: deriving a motion vector predictor by using motion information of a neighboring block of the current block; parsing layer information for indicating the current layer, to which a motion vector difference used for the inter prediction of the current block belongs, within a predefined layer structure in which a combination of motion vector differences between one or more horizontal and vertical components is classified into a plurality of layers; parsing index information for indicating a specific combination in the current layer; deriving a motion vector difference of the current block by using the layer information and the index information; and deriving a motion vector of the current block by adding the motion vector difference to the motion vector predictor.
1. A method for processing a video signal based on inter prediction by an apparatus, the method comprising:
deriving a motion vector predictor based on motion information for a neighboring block of a current block;
parsing layer information indicating a current layer to which a motion vector difference used for inter prediction of the current block belongs, in a predefined layer structure in which combinations of at least one horizontal and vertical components of motion vector differences are divided into a plurality of layers;
parsing index information indicating a specific combination in the current layer;
deriving a motion vector difference of the current block using the layer information and the index information; and
deriving a motion vector of the current block by adding the motion vector difference to the motion vector predictor,
wherein parsing the layer information includes:
parsing a first flag indicating whether an identification (ID) of the current layer is larger than 0, and
parsing a second flag indicating whether the ID of the current layer is larger than 1 when the ID of the current layer is larger than 0.
2. The method of claim 1 , wherein
parsing the layer information includes parsing remaining layer information indicating the current layer among layers whose IDs are equal to or larger than 2 when the ID of the current layer is larger than 1.
3. The method of claim 2 , wherein
the remaining layer information is binarized using an exponential Golomb code having an order of 1.
4. The method of claim 1 , wherein
the index information is binarized using a truncated binarization scheme.
5. The method of claim 1 , further comprising:
generating a prediction sample of the current block by performing inter prediction using the motion vector of the current block.
6. A method of encoding a video signal based on inter prediction by an apparatus, the method comprising:
deriving a motion vector of a current block based on the inter prediction;
deriving a motion vector predictor based on motion information for a neighboring block of the current block;
generating a motion vector difference of the current block based on the motion vector and the motion vector predictor of the current block;
generating layer information indicating a current layer to which the motion vector difference belongs, in a predefined layer structure in which combinations of at least one horizontal and vertical components of motion vector differences are divided into a plurality of layers; and
generating index information indicating a specific combination in the current layer,
wherein generating the layer information includes:
generating a first flag indicating whether an identification (ID) of the current layer is larger than 0, and
generating a second flag indicating whether the ID of the current layer is larger than 1 when the ID of the current layer is larger than 0.
7. The method of claim 6 , wherein generating the layer information includes:
generating remaining layer information indicating the current layer among layers whose IDs are equal to or larger than 2 when the ID of the current layer is larger than 1.
8. The method of claim 7 , further comprising:
binarizing the remaining layer information using an exponential Golomb code having an order of 1.
9. The method of claim 6 , further comprising:
binarizing the index information using a truncated binarization scheme.
10. The method of claim 6 , further comprising:
generating a residual sample of the current block by performing the inter prediction using the motion vector of the current block.
11. A non-transitory computer-readable storage medium for encoded image information generated by performing steps of:
deriving a motion vector of a current block based on inter prediction;
deriving a motion vector predictor based on motion information for a neighboring block of the current block;
generating a motion vector difference of the current block based on the motion vector and the motion vector predictor of the current block;
generating layer information indicating a current layer to which the motion vector difference belongs, in a predefined layer structure in which combinations of at least one horizontal and vertical components of motion vector differences are divided into a plurality of layers; and
generating index information indicating a specific combination in the current layer,
wherein generating the layer information includes:
generating a first flag indicating whether an identification (ID) of the current layer is larger than 0, and
generating a second flag indicating whether the ID of the current layer is larger than 1 when the ID of the current layer is larger than 0.