Audio encoding device, method, and program which controls the number of time groups in a frame using three successive time group energies

Abstract

[PROBLEMS] To provide a high-quality audio signal encoding technique by controlling the number of time/frequency groups in a frame. [MEANS FOR SOLVING PROBLEMS] An audio encoding device includes: a time group boundary candidate position extraction unit () for analyzing a sub-band signal () obtained by frequency-changing an input signal and calculating a candidate position of the time group boundary by comparing change in energy of three successive time groups; a time group quantity generation unit () for outputting a maximum value of the time group quantity; a time group selection unit () for generating a time group quantity not greater than the maximum time group quantity by using the candidate position; and a frequency group generation unit () for generating a frequency group by using the generated time group information. The device generates a time/frequency group accurately reflecting a change of the input signal and performs operations while controlling the number of time/frequency groups in the frame.