Method and apparatus for encoding/decoding MPEG-4 BSAC audio bitstream having ancillary information

摘要

The encoding method includes: converting an audio signal in the time domain to an audio signal in the frequency domain and quantizing the audio signal (400); counting the number of data bits (410); obtaining the number of available bits per layer (420); modifying the number of available bits per layer considering the size of ancillary information (430); encoding actual audio data in units of layers (440); and embedding ancillary information in the encoded bitstream (450). The decoding method includes: decoding a header (700); calculating a layer structure of the audio bitstream (710); determining a difference between a size of data up to a top layer and a size of a frame as the size of ancillary information (740); extracting the ancillary information according to the size of the ancillary information (750); and decoding the audio bitstream (730). When providing a service using BSAC by having ancillary information, meta data and sound quality of audio contents can be improved. <IMAGE>