Variable length code decoding apparatus and variable length code decoding method

Abstract

When a combination between a plurality of FIFO memories and a variable length coding table is used, a load generated by an increase in number of FIFO memories serving as output destinations of a codeword length output from the variable length coding table when the codeword length is output is reduced. A variable length code decoding apparatus includes an input unit which receives variable length coding data, a plurality of FIFO memories which store the variable length coding data and output or update the variable length coding data on the basis of a codeword length of the variable length coding data, a FIFO input selecting unit which outputs the variable length coding data to one of the plurality of FIFO memories, a variable length coding table storing unit which stores a variable length coding table representing a relationship between the variable length coding data, the codeword length and a decoding value, reads the variable length coding data stored in one of the plurality of FIFO memories, and compares the read variable length coding data with the variable length coding table, a table selecting unit which determines the codeword length and the decoding value on the basis of a comparison result of the variable length coding table storing unit, and outputs the determined codeword length to one of the plurality of FIFO memories, and a control unit which selects one of the plurality of FIFO memories as a destination FIFO memory, reads the variable length coding data from the input unit or one of the unselected FIFO memories, and controls the FIFO input selecting unit such that the read variable length coding data is output to the selected FIFO memory.