STEREO EXTENSION APPARATUS AND METHOD

摘要

According to the present invention, a stereo extension apparatus includes: a database which stores a predetermined information according to GMM training or HMM training; an MDCT conversion unit which converts a mono signal into an MDCT domain; a feature value extraction unit which extracts a feature value of the mono signal from an MDCT coefficient outputted from the MDCT conversion unit; a side signal energy estimation unit which estimates a subband energy of a side signal with reference to the information stored in the database based on the feature value; an energy control unit which acquires an MDCT coefficient of the side signal estimated from the subband energy of the estimated side signal; a reverse MDCT conversion unit which acquires an estimated side signal by performing a reverse MDCT conversion of the MDCT coefficient of the estimated side signal; and a stereo signal generation unit which acquires a stereo signal from the sum of the mono signal and the estimated side signal and a difference therebetween. According to the present invention, a stereo signal similar to an actual stereo signal and with improved sound quality can be obtained from a mono signal.