STEREOPHONIC AUDIO CODING AND DECODING METHOD/APPARATUS CAPABLE OF BIT-RATE CONTROL

摘要

PROBLEM TO BE SOLVED: To control bit rate by using a bit division arithmetic coding technique, which preferentially codes a more important component of one of two-channel signals and generating a bit stream including a basic hierarchy and many higher hierarchies. SOLUTION: A bit division arithmetic coding part 170 encodes frequency data value quantized at a quantization part 160 by combining additional information on a relevant band and quantization information given to audio data, based on a bit rate corresponding to each hierarchy. Meanwhile, a performance similar to AAC is made to be capable of being provided at the highest hierarchy. Then the part 170 limits the band corresponding to a basic hierarchy so as to control the bit rate and also encodes additional information on the basic hierarchy. Then information on the quantized value are encoded in the order covering the highest bit through the lowest one and also successively covering lowest frequency component through the highest one.