Code Excitation linear prediction encoder and decoder

摘要

A code excitation linear predictive (CELP) coding or decoding apparatus is provided in which a code vector, which is provided by a stochastic codebook (108), is converted adaptively in accordance with vocal tract analysis information (LPC) so that a high quality reproduction speech is obtained at a low coding rate. Further, in order to obtain a similar effect, a pulse-like excitation codebook formed of an isolated impulse is provided in addition to the adaptive excitation codebook (107) and stochastic excitation codebook (108) so that either the stochastic excitation codebook or the pulse-like excitation codebook is selectively used to provide a vocal tract parameter as a linear spectrum pair parameter.