Techniques described use a reference motion vector to reduce the amount of bits needed to encode motion vectors for inter prediction. One method includes determining a reference motion vector used to encode a current block of a current frame. The reference motion vector was selected by identifying, multiple candidate motion vectors used to inter predict blocks, and identifying a set of reconstructed pixel values from at least one block adjacent to the current block. For each candidate motion vector, a set of predicted pixel values for the set of reconstructed pixel value is generated using the candidate motion vector and a first reference frame, and an error value is calculated based on a difference between the sets of pixel values. Finally, a reference motion vector from the candidates is selected based on the error values. The method also includes decoding the current block using the reference motion vector.