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The quantized values are encoded using a prefix free binary code. To make matters more complicated there are up to 16 encoding scheme per quantizer (because the symbol set depends on the quantizer). In many cases, the symbols are built from a group of two or four quantized values instead of just one quantized value. For groups of size two, the trees are shown as table, the first symbol choosing the row, the second value the column.

Another catch is that some of the encoding schemes encoded the signed quantized values, while others encode only the absolute values of the quantized values. If only the absolute values are encoded in a symbol, each symbol is followed by one bit per absolute value that is not zero. If that bit is set, the value is negative.

The trees can be calculated as canonical huffman codes. Note that unsigned sorting (on two's complement numbers) is used, so negative numbers sort behind positive ones. The sort order for the grouped symbols is lexicographically by the single quantized numbers.

(i.e. symbol set -1,0,1)

(used for A/0)

(used for A/1)

(used for A/2 and B/1)

(used for A/3)

(used for A/4, B/2, B/6)

(used for A/5, B/3)

(used for A/6, B/5)

(used for A/7)

(absolute values followed by sign bits for nonzero)

(used for B/0)

(used for B/4)

(used for B/7)

(i.e. symbol set -3..+3)

(used for A/0, B/2)