Audio encoding method and device, audio decoding method and device, and multimedia device employing same

A method for encoding an audio signal comprises the steps of: generating a signal in a time domain transformed to compensate for a frequency resolution in frame units; performing analysis-windowing on the transformed signal in the time domain by using a window designed to have an overlap duration of less than 50%; and transforming the analysis-windowed signal in the time domain into a signal in a frequency domain. In addition, a method for decoding an audio signal comprises the steps of: restoring a frequency resolution by inverse-merging frequency bins in subband units for a signal in the frequency domain decoded from a bitstream; inverse-transforming the resolution-restored signal in the frequency domain into a signal in the time domain; and performing synthesis-windowing on the signal in the time domain by using a window designed to have an overlap duration of less than 50%.