Encoding device, decoding device and audio data distribution system

摘要

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 (f 1 ) 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, f 1 is a half or less of a sampling frequency f 2 at which the audio data string is created.