An apparatus for decoding transform coefficients using an alphabet of transform coefficient tokens, the apparatus comprising: a memory; and a processor configured to execute instructions stored in the memory to: determine a first probability distribution corresponding to a first context, the first probability distribution including a probability value for each of the transform coefficient tokens of the alphabet; determine a second probability distribution corresponding to a second context, wherein the alphabet of transform coefficient tokens is partitioned into non-overlapping subsets, wherein the subsets comprise at least one first subset consisting of one of the transform coefficient tokens and at least one second subset comprising a plurality of the transform coefficient tokens, the second probability distribution including a probability value for each of the subsets; and in response to determining that the second probability distribution includes a probability value for a transform coefficient token in the first subset, linear-combine a first conditional probability obtained by using the first probability distribution and a second conditional probability obtained by using the second probability distribution to generate a mixed probability for the transform coefficient token, entropy decode, from an encoded bitstream, the transform coefficient token using the mixed probability, and entropy decode, from an encoded bitstream, a transform coefficient in the at least one second subset using the first conditional probability. a memory; and a processor configured to execute instructions stored in the memory to: determine a first probability distribution corresponding to a first context, the first probability distribution including a probability value for each of the transform coefficient tokens of the alphabet; determine a second probability distribution corresponding to a second context, wherein the alphabet of transform coefficient tokens is partitioned into non-overlapping subsets, wherein the subsets comprise at least one first subset consisting of one of the transform coefficient tokens and at least one second subset comprising a plurality of the transform coefficient tokens, the second probability distribution including a probability value for each of the subsets; and in response to determining that the second probability distribution includes a probability value for a transform coefficient token in the first subset, linear-combine a first conditional probability obtained by using the first probability distribution and a second conditional probability obtained by using the second probability distribution to generate a mixed probability for the transform coefficient token, entropy decode, from an encoded bitstream, the transform coefficient token using the mixed probability, and entropy decode, from an encoded bitstream, a transform coefficient in the at least one second subset using the first conditional probability. determine a first probability distribution corresponding to a first context, the first probability distribution including a probability value for each of the transform coefficient tokens of the alphabet; determine a second probability distribution corresponding to a second context, wherein the alphabet of transform coefficient tokens is partitioned into non-overlapping subsets, wherein the subsets comprise at least one first subset consisting of one of the transform coefficient tokens and at least one second subset comprising a plurality of the transform coefficient tokens, the second probability distribution including a probability value for each of the subsets; and in response to determining that the second probability distribution includes a probability value for a transform coefficient token in the first subset, linear-combine a first conditional probability obtained by using the first probability distribution and a second conditional probability obtained by using the second probability distribution to generate a mixed probability for the transform coefficient token, entropy decode, from an encoded bitstream, the transform coefficient token using the mixed probability, and entropy decode, from an encoded bitstream, a transform coefficient in the at least one second subset using the first conditional probability. linear-combine a first conditional probability obtained by using the first probability distribution and a second conditional probability obtained by using the second probability distribution to generate a mixed probability for the transform coefficient token, entropy decode, from an encoded bitstream, the transform coefficient token using the mixed probability, and entropy decode, from an encoded bitstream, a transform coefficient in the at least one second subset using the first conditional probability.