Audio decoding method and apparatus which recover high frequency component with small computation

摘要

A method and apparatus for performing audio post processing using mode information that indicates the degree of similarity between a right channel signal and a left channel signal in MPEG-1 layer 3 audio data, are provided. If the difference between the two channel signals is small, a first mode is used in which the high frequency component of only one channel is recovered and the recovered high frequency component is used to recover the high frequency component of the other channel. If the difference between the two channel signals is large, a second mode is selected in which the high frequency component in only one of every two frames is recovered alternately in the left channel and the right channel and the high frequency component of each of the skipped frames is interpolated based on the high frequency components of the previous frame and the next frame.