Decoding apparatus, method, and storage medium for inputting and decoding variable-length coded data

Abstract

A decoding apparatus has: M tables for storing, in correspondence with M types of variable-length code tables, minimum code words or maximum code words of classes of variable-length code words constructing a variable-length code table; a table selector which selects one table from the M tables; N comparators which compare input coded data with the minimum code words or maximum code words outputted from the table selected by the table selector; a switch circuit and a priority encoder which obtain a class number corresponding to an initial code word of the input coded data based on results of comparison by the N comparators; a code length converter which converts the class number into a code length; and an address generator which generates an address to access a memory holding decoded data from the class number and the code length outputted said code length converter. The data outputted from the memory based on the address becomes decoded data of the input coded data.