Vorrichtung zur Kodierung und Dekodierung von Audiosignalen

摘要

An audio signal coding apparatus comprises a first-stage encoder for quantizing the time-to-frequency transformed audio signal; second-and-subsequent-stages of encoders each for quantizing a quantization error output from the previous-stage encoder; a characteristic decision unit which decides the frequency band of an audio signal to be quantized by each encoder of multiple-stage encoders; and a coding band control unit which receives the frequency band decided by the characteristic decision unit and the time-to-frequency transformed audio signal, decides the order of connecting the respective encoders, and transforms the quantization bands of the encoders and the connecting order to code sequences. Therefore, it is possible to provide an audio signal coding apparatus performing adaptive scalable coding, which exhibits sufficient performance when coding various audio signals.