DECODER, PROGRAM AND METHOD FOR DECODING VARIABLE LENGTH CODE

摘要

PROBLEM TO BE SOLVED: To provide a decoder, a program and a method for decoding a variable length code in which decoding rate can be enhanced. SOLUTION: A set of final recovery values is acquired by retrieving a decoding table T1 storing a set of final recovery values, where quantized coefficient values are collected with a predetermined order depending on an inputted variable length code bit sequence, as a recovery event and then the variable length code bit sequence is decoded. Consequently, the set of final recovery values can be obtained immediately upon ending decoding of the variable length code. Since individual final recovery values can be taken out using only a shift instruction or an AND instruction requiring a small number of steps, the final recovery value can be obtained without requiring four operations (especially, division) requiring a large number of steps. Consequently, total number of processing steps is decreased and decoding rate can be enhanced.