1. A method of decoding video data, the method comprising: determining, for each reference picture in one or more reference picture lists for a current picture, whether to include the reference picture in a plurality of reference pictures for determining at least one motion vector predictor for a current block in the current picture, wherein the determination is based at least in part on whether the reference picture is a short-term reference picture or a long-term reference picture; determining, for at least one co-located block of the current block of video data in at least one picture of the plurality of reference pictures, whether a forward motion vector or a backward motion vector of the at least one co-located block of video data is used to derive the at least one motion vector predictor; determining the at least one motion vector predictor for the current block of the current picture based on the determination of whether the forward motion vector or the backward motion vector is used, one or more motion vectors of the at least one co-located block, and a comparison of a picture order count (POC) value of each picture of the plurality of reference pictures to a POC value of the current picture; and decoding a motion vector for the current block of video data relative to the at least one motion vector predictor.