AUDIO SIGNAL HIGH EFFICIENCY CODER

摘要

PURPOSE:To obtain a coder capable of outputting a high efficiency coding signal in which sound quality after inverse matrix processing is improved by providing a deficient bit calculation section calculating the deficient quantization bit number of the frequency area signal of the inverse matrix processing signal of an audio signal subjected to high efficiency coding processing and an additional bit allocation section to the coder. CONSTITUTION:The coder is provided with a deficient bit calculation section 10 and an additional bit allocation section 11 allocating additional bits based on it. The deficient bit calculation section 10 calculates an audible limit signal level by taking the masking effect of an audible sense into account based on the frequency area signal of a reference signal for each channel, calculates the deficient bit number of the frequency region subjected to high efficiency coding processing based on the frequency area signal being a difference between the reference signal and the signal subjected to high efficiency coding processing and on an audible limit signal level and provides the output to the additional bit allocation section 11. The additional bit allocation section 11 allocates additional bits remaining after initial bit allocation in the order of a frequency area signal with higher deficient bit requirement.