SCALABLE AUDIO ENCODER/DECODER AND AUDIO ENCODING/DECODING METHOD

摘要

PURPOSE: A bit rate controllable audio encoding/decoding method and apparatus are provided which flexibly changes the size of bit stream or the complexity of a decoder according to the performance of the decoder or user's request. CONSTITUTION: To encode an audio signal into a hierarchical data stream configured of a basic layer and a predetermined number enhancement layers, the input audio signal is processed to be quantized by coding bands. Quantized data corresponding to a basic layer is coded within a predetermined layer size. Quantized data belong to the enhancement layer following the coded layer and quantized data belong to the coded layer that was not coded are coded within a predetermined layer size. The layer coding is performed for all layers. The coding processes are carried out through the first step of representing quantized data corresponding to a layer to be coded in digits, and the second step of coding the data from the most significant digit sequence to digital sequences having lower significance.