APPARATUS AND METHOD FOR AUDIO ENCODING/DECODING WITH SCALABILITY

摘要

An apparatus and a method for encoding audio data, and an apparatus and a method for decoding the audio data are provided to restore audio data of all layers even though audio data included in a bit-stream to be decoded are encoded audio data of some layers. A bit-stream analyzing unit(810) extracts audio data from a bit-stream. The audio data have encoded SBR(Spectral Band Replication) data and one or more layers, wherein each of layers is expressed and encoded in a predetermined number of bits. A scalable decoding unit(820) decodes the encoded audio data by decoding a lower layer prior to an upper layer and decoding an upper bit prior to a lower bit in each layer. A SBR decoding unit(830) decodes the encoded SBR data, and estimates audio data of more than a first frequency but less than a second frequency based on the decoded audio data and the decoded SBR data. A data composite unit(840) generates composite data using the decoded audio data and the estimated audio data, and outputs the composite data as the audio data of more than the first frequency but less than the second frequency. The second frequency is higher than the maximum frequency of the at least one layer. The SBR data has information on the audio data of higher than the first frequency but lower than the second frequency.