1. An apparatus, comprising: an encoder for encoding bi-predictable picture data for at least a portion of a picture using adaptive geometric partitioning, wherein geometric partitions for the adaptive geometric partitioning are predicted using at least one predictor selected from a first set of predictors corresponding to a first list of reference pictures, a second set of predictors corresponding to a second list of reference pictures, and a third set of predictors used for bi-prediction and including predictors from at least one of the first and second sets.