Methods and apparatuses for video processing include: splitting a target basic processing unit (BPU) of a target picture into a set of basic processing sub-units (BPSUs); determining a set of collocated BPUs in a reference picture associated with the target picture, wherein a BPSU of the set of BPSUs corresponds to a collocated BPU of the set of collocated BPUs; determining a motion vector associated with the BPSU based on motion information associated with the corresponding collocated BPU; and applying motion compensation for each of the set of BPSUs based on the motion vector associated with the BPSU.