1. A method of decoding video data, the method comprising: receiving a plurality of intra-encoded blocks of video data, wherein each block of the plurality is encoded according to one of a plurality of intra prediction modes and one of a plurality of transforms, wherein each intra prediction mode corresponds to a particular most probable transform, and wherein each intra prediction mode is ambiguous as to an actual transform; for at least one block of the plurality of intra-encoded blocks of video data: determining an intra-prediction mode for the block of video data; identifying a most probable transform based on the determined intra-prediction mode, wherein the most probable transform corresponds to a first non-square shape transform block; receiving a first syntax element indicating whether the most probable transform is a transform used to encode the block of video data; in response to the most probable transform being the transform used to encode the block of video data, reconstructing the block of video based on the most probable transform without receiving an additional syntax element indicating an actual intra prediction mode; and in response to the most probable transform being a transform other than the transform used to encode the block of video data: receiving a second syntax element that identifies the transform used to encode the block of video data, wherein the transform used to encode the block of video data comprises one of a transform that corresponds to a square-shape transform block or a transform that corresponds to a second non-square shape transform block, and wherein the transform used to encode the block of video data is different than the most probable transform; and reconstructing the block of video data based on the transform identified by the second syntax element.