1. A method of decoding coefficients in a video decoding process, the method comprising: determining statistics of coefficient levels for previously decoded coefficients of residual video data for each of a plurality of different categories of coefficient groups, wherein the different categories are defined based on characteristics of transform blocks that include the coefficient groups, and wherein the characteristics of the transform blocks of the previously decoded coefficients include whether the transform blocks are luma blocks and whether the transform blocks are transform skip blocks, the previously decoded coefficients being decoded prior to decoding a current coefficient group in a transform block of the residual video data; determining a category of the current coefficient group from the plurality of different categories based on characteristics of the transform block that includes the current coefficient group, wherein the characteristics of the transform block that includes the current coefficient group include whether the transform block is a luma block and whether the transform block is a transform skip block; prior to decoding any coefficients in the current coefficient group, determining an initial value of a Rice parameter for the current coefficient group based on the statistics for the determined category of the current coefficient group; and decoding a remaining absolute value of a coefficient level for at least one of the coefficients in the current coefficient group using codes defined by the initial value of the Rice parameter.