Motion vector prediction fusion for subblock-based temporal motion vector prediction (sbtmvp) and temporal motion vector prediction (tmvp)

Abstract

Method, apparatus, and non-transitory storage medium for fusing sub-block motion vector predictors into one sub-block motion vector predictor during video coding and decoding is provided. The method may include deriving a first displacement vector for a sub-block of a current block identifying a co-located sub-block of a co-located picture, and based on the identified co-located sub-block, determine whether the co-located sub-block overlaps with one or more sub-blocks associated with a motion field grid in the co-located picture. Based on determining that the co-located sub-block overlaps with the one or more sub-blocks, the method may include, retrieving two or more sub-block motion vectors respectively associated with the one or more sub-blocks. A final motion vector predictor for the sub-block of the current block may be derived based on the two or more sub-block motion vectors retrieved.