METHOD FOR ENCODING AND DECODING AUDIO, AND APPARATUS THEREFOR

摘要

PURPOSE: A method for encoding and decoding audio, and an apparatus therefor are provided to realize a CELP(Code-Excited Linear Prediction) system encoder in a lower data rate. CONSTITUTION: A framer(401) collects and stores voice data. A preprocessor(402) executes high-band filtering to remove direct current components from the voice data. A voice spectrum analyzing part executes short term linear prediction from the filtered voice signals to extract a voice spectrum. A formant weighting filter(405) filters the preprocessed voice for widening an error range in a formant area in adaptation and codebook search. A harmonic noise shaping filter(406) widens an error range in a pitch on-set area. An adaptation codebook search unit searches an adaptation codebook by using an open-loop patch extracted based on a residual of voice. A renewal codebook search unit searches a renewal excited codebook generated from an adaptation codebook excited signal. Predetermined bits are assigned to various parameters for forming bit streams.