An apparatus for decoding transform coefficients using an alphabet of transform coefficient tokens includes a memory and a processor. The processor is configured to execute instructions stored in the memory to select a first probability distribution corresponding to a first context, select a second probability distribution corresponding to a second context, and, in response to determining that the second probability distribution includes a probability for a transform coefficient token, mix the first probability distribution and the second probability distribution to generate a mixed probability and entropy decode, from an encoded bitstream, the transform coefficient token using the mixed probability. The first probability distribution is defined for all tokens of the alphabet. The second probability distribution is defined over a non-trivial partition of the tokens.