1. A method for decoding video data, the method comprising: receiving, in a bitstream, significance syntax elements of transform coefficients for a current sub-block of a block; selecting a context pattern from a plurality of context patterns, wherein the context pattern identifies contexts for two or more scan types of the current sub-block, wherein the plurality of context patterns are stored as respective one-dimensional context patterns and generated from a plurality of two-dimensional context patterns, wherein each one-dimensional context pattern includes context values from a horizontal, vertical, or diagonal scan of the two-dimensional context patterns, wherein a first context pattern of the plurality of context patterns comprises context values that are the same as context values of a first two-dimensional context pattern scanned horizontally and a second two-dimensional context pattern scanned vertically, and wherein only the first context pattern is stored to represent both a horizontal scan of the first two-dimensional context pattern and a vertical scan of the second two-dimensional context pattern; assigning contexts to the significance syntax elements of the transform coefficients for the current sub-block based on the selected context pattern; and context adaptive binary arithmetic coding (CABAC) decoding the significance syntax elements of the transform coefficients of the current sub-block based on the assigned contexts.