Variable-length code table and variable-length coding device

Abstract

A variable-length code table, which is used for producing a variable-length code from data formed of one set of first and second equal-length components, stores at an address uniquely assigned by the one set of the equal-length components a corresponding variable-length code and a code length of the variable-length code. Combination of the first and second equal-length components is preselected such that the maximum value of the absolute value of the first equal-length component increases as the absolute value of the second equal-length component combined therewith decreases. The second equal-length components are classified into a plurality of classes in accordance with the magnitude of the absolute value. Each address includes a first region having a value and a length uniquely specified based on the class including the second equal-length component, a second region storing the first equal-length component, and a third region storing the second equal-length component, and is constructed to have a fixed length as a whole. Region lengths of the second and third regions are determined correspondingly to the class including the second equal-length component, and each are specifically determined to have the minimum value required for storing the maximum values of the absolute values of the first and second equal-length components of the combinations of the equal-length components included in the corresponding class.