Obtaining one or more motion vector predictor candidates includes: (a1) generating a motion vector predictor candidate, based on motion vectors of first adjacent blocks adjacent to a block to be processed in a first direction; and (a2) generating a motion vector predictor candidate, based on motion vectors of second adjacent blocks adjacent to the block to be processed in a second direction, and step (a2) includes: determining whether the first adjacent blocks include an inter-predicted block; and searching for a motion vector on which scaling processing can be performed from among the motion vectors of the second adjacent blocks when it is determined that the first adjacent blocks do not include an inter-predicted block, and executing, when the motion vector on which scaling processing can be performed is obtained in the search, scaling processing on the motion vector obtained in the search.

A video signal processing method and apparatus for encoding or decoding a video signal is disclosed. More particularly, a video signal processing method and a video signal processing apparatus using the same are disclosed, wherein a method for processing a video signal comprises the steps of: obtaining a set of control point motion vectors for prediction of a current block; obtaining the motion vector of each sub-block of the current block using control point motion vectors of the set of control point motion vectors; obtaining a predictor of the each sub-block of the current block using the motion vectors of the each sub-block; obtaining a predictor of the current block by combining predictors of the each sub-block; and restoring the current block using the predictor of the current block.

A method and an apparatus for video decoding are disclosed. The apparatus decodes prediction information of a current block from a coded video bitstream. The prediction information indicates an intra block copy mode. The current block is one of a plurality of coding blocks in a current region of a current coding tree block (CTB) in a current picture. The apparatus determines whether the current block is to be reconstructed first in the current region. When the current block is to be reconstructed first in the current region, the apparatus determines a block vector for the current block where a reference block indicated by the block vector is in a search range in the current picture that excludes a collocated region in a previously reconstructed CTB. A position of the collocated region in the previously reconstructed CTB has a same relative position as the current region in the current CTB.

Provided is a video decoding method including: generating a merge candidate list including neighboring blocks referred to predict a motion vector of a current block in a skip mode or a merge mode; when a merge motion vector difference is used according to merge difference mode information indicating whether the merge motion vector difference and a motion vector determined from the merge candidate list are used, determining a base motion vector from a candidate determined among the merge candidate list based on merge candidate information; determining the motion vector of the current block by using the base motion vector and a merge motion vector difference of the current block, the merge motion vector difference being determined by using a distance index and direction index of the merge motion vector difference of the current block; and reconstructing the current block by using the motion vector of the current block.

Provided is a video decoding method including: generating a merge candidate list including neighboring blocks referred to predict a motion vector of a current block in a skip mode or a merge mode; when a merge motion vector difference is used according to merge difference mode information indicating whether the merge motion vector difference and a motion vector determined from the merge candidate list are used, determining a base motion vector from a candidate determined among the merge candidate list based on merge candidate information; determining the motion vector of the current block by using the base motion vector and a merge motion vector difference of the current block, the merge motion vector difference being determined by using a distance index and direction index of the merge motion vector difference of the current block; and reconstructing the current block by using the motion vector of the current block.

A video processing method is disclosed to include: generating one or more initial predictions for a sub-block of a current video block of the video; refining the one or more initial predictions to generate a final prediction block using a prediction refinement with optical flow (PROF) procedure by calculating motion vector differences based on variables having a bit width not exceeding a predetermined maximum bit width; and performing a conversion between the current video block and a coded representation of the video using the variables having the bit width not exceeding the predetermined maximum bit width.

A video processing method is disclosed to include: generating one or more initial predictions for a sub-block of a current video block of the video; refining the one or more initial predictions to generate a final prediction block using a prediction refinement with optical flow (PROF) procedure by calculating motion vector differences based on variables having a bit width not exceeding a predetermined maximum bit width; and performing a conversion between the current video block and a coded representation of the video using the variables having the bit width not exceeding the predetermined maximum bit width.

A method of decoding motion information according to an embodiment includes: obtaining information indicating a disparity distance for determining a prediction motion vector of a current block; scaling the disparity distance corresponding to the obtained information, based on a comparison result between a base pixel unit and a smallest pixel unit indicatable by a motion vector of the current block; determining a prediction motion vector candidate changed by the scaled disparity distance from a base motion vector of the current block from among one or more prediction motion vector candidates as the prediction motion vector of the current block; and determining the motion vector of the current block by using the prediction motion vector.

A method of decoding motion information according to an embodiment includes: obtaining information indicating a disparity distance for determining a prediction motion vector of a current block; scaling the disparity distance corresponding to the obtained information, based on a comparison result between a base pixel unit and a smallest pixel unit indicatable by a motion vector of the current block; determining a prediction motion vector candidate changed by the scaled disparity distance from a base motion vector of the current block from among one or more prediction motion vector candidates as the prediction motion vector of the current block; and determining the motion vector of the current block by using the prediction motion vector.

Sub-block merge motion field is combined with triangle partitioning and geometric partitioning modes to further give coding and decoding schemes flexibility. In at least one embodiment, a flag is used to signal if sub-block merge candidates are used in place of regular merge candidates. In another embodiment, regular merge candidates are replaced by sub-block merge candidates. In another embodiment, at least one motion field is stored. In another embodiment, all sub-block merge candidates or only sub-block temporal motion vector predictors or only affine predictors are considered.