Apparatus and method of encoding audio data and apparatus and method of decoding encoded audio data

摘要

An apparatus and method of encoding audio data and an apparatus and method of decoding encoded audio data are provided. According to another aspect of the present invention, there is provided an audio data decoding apparatus comprising: a bitstream analysis unit extracting encoded SBR data and encoded audio data corresponding to at least one layer, the layer being expressed in predetermined numbers of bits, from a given bitstream; a scalable decoding unit decoding the encoded audio data by decoding lower layer earlier than upper layer and the upper bit of each layer earlier than the lower bit of each layer; a SBR decoding unit decoding the encoded SBR data, and inferring audio data in a frequency band between a first frequency and a second frequency based on the decoded audio data and the decoded SBR data; and a data synthesis unit producing synthetic data by using the decoded audio data and the inferred audio data and outputting the synthetic data as the audio data in the frequency band between 0 and the second frequency, wherein the second predetermined frequency is equal to or greater than the maximum frequency of the at least one layer, and the SBR data comprises information about the audio data in the frequency band between the first and the second frequencies.