1. A method of decoding video data, the method comprising: determining a first most probable intra-prediction mode and a second most probable intra-prediction mode for a current block of video data based on a context for the current block; performing a context-based adaptive binary arithmetic coding (CABAC) process to determine a received codeword corresponding to a modified intra-prediction mode index; determining an intra-prediction mode index, wherein determining the intra-prediction mode index comprises comparing the modified intra-prediction mode index to an intra-prediction mode index for the first most probable intra-prediction mode and an intra-prediction mode index for the second most probable intra-prediction mode; selecting, based on a mapping of intra-prediction mode indexes to intra-prediction modes, an intra-prediction mode other than the first most probable intra-prediction mode and second most probable intra-prediction mode to use to decode the current block, wherein the selected intra-prediction mode corresponds to the determined intra-prediction mode index, wherein each of the first most probable intra-prediction mode and the second most probable intra-prediction mode corresponds to a respective intra-prediction mode index, wherein when the modified intra-prediction mode index plus one is greater than or equal to the intra-prediction mode index for the first most probable intra-prediction mode and greater than or equal to the intra-prediction mode index for the second most probable intra-prediction mode, selecting the intra-prediction mode comprises selecting the intra-prediction mode having an intra-prediction mode index that is two greater than the modified intra-prediction mode index; and decoding the current block using the selected intra-prediction mode.