A method for inter-prediction of a current image block in a current picture of a video, the method being used for a merge mode and comprising when a flag is signaled at a sequence parameter set level and/or a picture level indicating that decoder-side motion vector refinement, DMVR, is enabled at the sequence parameter set level and/or the picture level: determining (705, 807, 903) whether a first temporal distance is equal to a second temporal distance, wherein the first temporal distance is represented in terms of a difference between a picture order count value of the current picture and a picture order count value of a first reference picture; and the second temporal distance is represented in terms of a difference between a picture order count value of a second reference picture and the picture order count value of the current picture; performing a decoder-side motion vector refinement, DMVR, procedure (707, 809, 905) to determine a prediction block of the current image block when it is determined that the first temporal distance is equal to the second temporal distance; and performing no decoder-side motion vector refinement, DMVR, procedure on the current image block, when it is determined that the first temporal distance is not equal to the second temporal distance; wherein the performing the DMVR procedure comprises: determining positions of a pair of first and second reference blocks, from positions of a plurality of pairs of first and second reference blocks based on a matching cost criterion, wherein the positions of the pair of first and second reference blocks includes a position of a first reference block that is of the first reference picture and that is determined based on a first initial motion vector pointing to a first initial reference block and a position of a second reference block that is of the second reference picture and that is determined based on a second initial motion vector pointing to a second initial reference block, wherein a direction of an offset of the position of the first reference block relative to the position of the first initial reference block is opposite to a direction of an offset of the position of the second reference block relative to the position of the second initial reference block and a magnitude of the offset of the position of the first reference block relative to the position of the first initial reference block is the same as a magnitude of the offset of the position of the second reference block relative to the position of the second initial reference block, and wherein the matching cost criterion is based on a cost comparison between the first reference block and the second reference block; wherein a first refined motion vector and a second refined motion vector are associated with the position of the first reference block and the position of the second reference block, respectively. determining (705, 807, 903) whether a first temporal distance is equal to a second temporal distance, wherein the first temporal distance is represented in terms of a difference between a picture order count value of the current picture and a picture order count value of a first reference picture; and the second temporal distance is represented in terms of a difference between a picture order count value of a second reference picture and the picture order count value of the current picture; performing a decoder-side motion vector refinement, DMVR, procedure (707, 809, 905) to determine a prediction block of the current image block when it is determined that the first temporal distance is equal to the second temporal distance; and performing no decoder-side motion vector refinement, DMVR, procedure on the current image block, when it is determined that the first temporal distance is not equal to the second temporal distance; wherein the performing the DMVR procedure comprises: determining positions of a pair of first and second reference blocks, from positions of a plurality of pairs of first and second reference blocks based on a matching cost criterion, wherein the positions of the pair of first and second reference blocks includes a position of a first reference block that is of the first reference picture and that is determined based on a first initial motion vector pointing to a first initial reference block and a position of a second reference block that is of the second reference picture and that is determined based on a second initial motion vector pointing to a second initial reference block, wherein a direction of an offset of the position of the first reference block relative to the position of the first initial reference block is opposite to a direction of an offset of the position of the second reference block relative to the position of the second initial reference block and a magnitude of the offset of the position of the first reference block relative to the position of the first initial reference block is the same as a magnitude of the offset of the position of the second reference block relative to the position of the second initial reference block, and wherein the matching cost criterion is based on a cost comparison between the first reference block and the second reference block; wherein a first refined motion vector and a second refined motion vector are associated with the position of the first reference block and the position of the second reference block, respectively.