In a method for video decoding in a decoder, prediction information of a block is decoded in a current picture from a coded video bitstream. The prediction information includes a plurality of offset indices for prediction offsets associated with an affine model in an inter prediction mode. The plurality of offset indices includes at least one of a distance offset index, an offset direction index, a delta scaling index, and a delta rotation index. Further, parameters of the affine model are determined based on the plurality of offset indices. Each of the plurality of the offset indices including a respective pre-defined mapping table that includes indexes and corresponding offset values. The parameters of the affine model are used to transform between the block and a reference block in a reference picture that has been reconstructed. At least a sample of the block is reconstructed according to the affine model.