Patent attributes
An audio data input unit of an encoding device splits an audio data string into contiguous samples of audio data, and a transforming unit transforms the split audio data into spectral data in a frequency domain. A data dividing unit divides the spectral data into a lower frequency band and a higher frequency band at 11.025 kHz (f1) as a boundary. The spectral data in the lower frequency band is quantized and encoded by a first quantizing unit and an encoding unit. A second quantizing unit generates sub information indicating a characteristic of the spectral data in the higher frequency band, and a second encoding unit encodes the sub information. A stream output unit integrates the codes obtained by the first and second encoding units and outputs the integrated one. Here, f1 is a half or less of a sampling frequency f2 at which the audio data string is created.