Various embodiments for decoding a current block of a picture are provided. One or more candidates of a first type are derived, with each of the candidates having a first motion vector predictor derived from a first motion vector that has been used to decode a first block. A candidate of a second type is derived, with the candidate having a second motion vector predictor. The candidate of the second type is different from the candidates of the first type. A coded index corresponding to a selected candidate is decoded. The selected candidate is one of a plurality of candidates which includes the candidates of the first type and the candidate of the second type. A total number of the candidates of the first type is less than a predetermined maximum candidate number which is fixed for all blocks in the picture.