Methods for Reducing the Bit Rate in G.729 Speech Codec

摘要

Conjugate structure algebraic CELP (G.729) is a voice codec that compresses speech signal based on model parameter of human voice. G.729 is a 8kbits/s speech coder. This paper deals with the reduction of the bit rate in G.729 coder while maintaining the same quality of speech. It proposes two methods; one is to send less number bits if there is no voice detection in the signal. Another is conditional search in fixed codebook which improves the speech quality.