CODING METHOD OF AUDIO DATA BY USING A BAND EXPANDING METHOD AND A DEVICE THEREOF, AND A DECODING METHOD AND A DEVICE THEREOF, CONCERNED WITH REALIZING AN EXCELLENT RESOLVING POWER OF TIME/FREQUENCY AXES

摘要

PURPOSE: A coding method of audio data by using a band expanding method, a device thereof, and a decoding method and a device thereof are provided to supply a more delicate FGS(Fine Grain Scalability) with a small amount of data based on an arithmetic coding method, and to configure a frequency resolving power as being similar to a transfer function of a user's ear based on a PWT(Pseudo Wavelet Transform). CONSTITUTION: A coding device outputs band restricted audio data, and generates band expanding information for a base layer(1001). The coding device PWT-converts the band restricted audio data according to each layer(1002), and performs a quantization process(1003). The coding device carries out an arithmetic coding process, and packages in layer structure(1004). The coding device multiplexes the coded band restricted audio data and the band expanding information, and outputs an audio bit stream(1005).