A video encoding method of estimating a motion vector of a current block in a current frame includes identifying a reference block in a reference frame, a first location of the current block within the current frame corresponding to a second location of the reference block within the reference frame, setting a search range in the reference frame, searching for candidate blocks from the search range of the reference frame, each of the candidate blocks satisfying a corresponding first motion estimation criterion of first motion estimation criteria, searching for a prediction block from among the candidate blocks, the prediction block satisfying a second motion estimation criterion, estimating, as the motion vector of the current block, a motion vector corresponding to a displacement between the reference block and the prediction block, and encoding the current block based on the estimated motion vector.

A moving for transmitting a bitstream via network is provided. A first candidate is derived from a first motion vector that has been used to decode a first block. The first block is adjacent to a current block. A second candidate having a second motion vector that is a non-zero value vector based on an X-Y axis of a fixed offset value is derived. The second motion vector is not derived by decoding a block adjacent to the current block and the fixed offset value is a non-zero value. An index to select a candidate used for coding the current block from a plurality of candidates, including the first candidate and the second candidate, is determined. The current block is coded by including the determined index.

A moving for transmitting a bitstream via network is provided. A first candidate is derived from a first motion vector that has been used to decode a first block. The first block is adjacent to a current block. A second candidate having a second motion vector that is a non-zero value vector based on an X-Y axis of a fixed offset value is derived. The second motion vector is not derived by decoding a block adjacent to the current block and the fixed offset value is a non-zero value. An index to select a candidate used for coding the current block from a plurality of candidates, including the first candidate and the second candidate, is determined. The current block is coded by including the determined index.

The present invention relates to a method for encoding/decoding a video. To this end, the method for decoding a video may include: generating a merge candidate list of a current block including at least one merge candidate corresponding to each of a plurality of reference picture lists; determining at least one piece of motion information by using the merge candidate list; and generating a prediction block of the current block by using the determined at least one piece of motion information.

A method and apparatus for encoding of a video sequence in an encoder or decoding of the video sequence in a decoder includes parsing an initial motion vector from the video sequence associated with a block. A plurality of samples are determined and pre-fetched to permit both motion vector refinement and motion compensation based on parsing the initial motion vector. Motion vector refinement is performed to determine a final motion vector using a first subset of the plurality of samples, and motion compensation is performed using a second subset of the plurality of samples.

The present invention relates to a method for encoding/decoding a video. To this end, the method for decoding a video may include: generating a merge candidate list of a current block including at least one merge candidate corresponding to each of a plurality of reference picture lists; determining at least one piece of motion information by using the merge candidate list; and generating a prediction block of the current block by using the determined at least one piece of motion information.

The present disclosure provides an inter prediction method, comprising the steps of obtaining an initial motion vector and a reference picture for bi-prediction; obtaining sets of candidate sample positions in the reference picture according to the initial motion vector and candidate motion vectors, wherein each candidate motion vector is derived by the initial motion vector and a respective motion vector offset, and wherein each set of candidate sample positions corresponds to each candidate motion vector; obtaining a respective set of sample positions from each set of candidate sample positions; computing a matching cost for each candidate motion vector within each set of sample positions; obtaining a refined motion vector based on the computed matching cost of each candidate motion vector; and obtaining prediction values for a current block based on the refined motion vector.

A video decoding method includes: deriving an L0 motion vector and an L1 motion vector for a current block; deriving a refined L0 motion vector and a refined L1 motion vector, by applying DMVR to the current block based on DMVR flag information; deriving L0 prediction samples of the current block based on the refined L0 motion vector and L1 prediction samples of the current block based on the refined L1 motion vector; deriving prediction samples for the current block based on the L0 prediction samples and the L1 prediction samples, by applying BDOF to the current block based on BDOF flag information; and generating reconstruction samples for the current block based on the prediction samples, in which the DMVR flag information is derived based on a predetermined DMVR application condition, and the BDOF flag information is derived based on a predetermined BDOF application condition.

A video processing method includes determining, for a conversion between a current video block of a video including multiple video blocks and a coded representation of the video, and from types of reference pictures used for the conversion, applicability of a coding tool to the current video block and performing the conversion based on the determining. The method may be performed by a video decoder or a video encoder or a video transcoder.

A method and a device for encoding or decoding video data. It concerns more particularly the encoding according to a particular encoding mode using a decoder side motion vector derivation mode referenced as frame-rate up conversion mode or FRUC mode. In FRUC merge mode, the derivation process comprises a refinement step to increase the accuracy of the obtained motion vector at the sub-pixel level. This process involves the evaluation of different sub-pixel position around the obtained motion vector according to different patterns. The present invention has been devised to improve the known refinement step. It aims at improving the coding efficiency by considering the characteristics of the matching type and/or the signal inside the templates.