1. A method for estimating a motion vector for transcoding digital video, the method comprising: storing digital video data in a storage unit; retrieving the digital video data from the storage unit via a processing unit; selecting a direction of an adjustment vector for estimation of a motion vector within a search region via the processing unit, wherein selecting the direction of the adjustment vector further comprises: calculating a plurality of SADs (sum of absolute difference) with respect to a plurality of adjustment vectors centering around an existing motion vector within the search region; selecting a first adjustment vector having a minimum value among the plurality of SADs; selecting a second adjustment vector having a next least minimum value among the plurality of SADs; adding the first adjustment vector and the second adjustment vector to create a third adjustment vector; determining the direction of the adjustment vector according to the third adjustment vector; and selecting the adjustment vector having a minimum SAD within the search region, wherein the first adjustment vector and the second adjustment vector are selected from the same plurality of SADs within the search region.