Video processing methods and apparatuses for coding a current block by constructing a candidate set including an average candidate generated from two or more original motion candidates. At least one MV of the average candidate is derived by directly averaging MVs of the original motion candidates in one of list 0 and list 1 without scaling regardless whether the MVs are pointing to same or different reference pictures. A selected candidate is determined from the candidate set as a MVP for a current MV of the current block for encoding or decoding the current block.