AUDIO ENCODING METHOD AND APPARATUS FOR NOISE REDUCTION

摘要

PURPOSE: An audio signal coding method and device for attenuating noise are provided to attenuate the noise inside an encoder properly to a multiple frame size and a moving picture experts group (MPEG) advanced audio coding (AAC) structure in an MPEG ACC process, thereby reducing computational complexity, and maintaining a performance for attenuating the noise. CONSTITUTION: An audio signal coding method for attenuating noise includes: steps (600,602) of receiving an audio signal, and dividing the audio signal into a long block and a short block through modified discrete cosine transformation; a step of attenuating the noise in the audio signal in response to the long and the short block; and a step (614) of implementing an advanced audio coding (AAC) process on the long and the short block in which the noise is attenuated. [Reference numerals] (600) Input an audio signal; (602) MDCT conversion; (604) Long block or a short block?; (606) Divide the long block into sub blocks; (608) Measure SNR for each sub band; (610) Deduct a spectrum; (612) Masking; (614) AAC encoding; (616) Divide the short band into sub blocks; (618) Power-match the short block with the long block; (620) Spectrum decrease; (AA) Start; (BB) Short block; (CC) Long block; (DD) Bit stream