CODEBOOK SEARCHING APPARATUS AND METHOD OF ACELP SOUND COMPRESSOR

摘要

PURPOSE: An apparatus and method are provided to search a codebook for selecting a code vector necessary in a process which compresses a sound signal in ACELP(A Code Excited Linear Prediction Sound Compressor). CONSTITUTION: An importance calculator(1110) calculates importance of each pulse which forms an input code vector. A minimum importance pulse determining section(1130) receives the importance of each pulse which forms an input code vector from the importance calculator(1110) and determines a pulse having a minimal importance to be removed. A new track determining section(1140) determines a new track in order to search a new pulse which is substituted for the pulse to be removed. A minimum importance pulse removing section(1150) outputs a code vector having (N-1) pulses by removing a minimum importance pulse from an initial code vector. A pulse searching device(1160) searches one pulse based on (N-1) pulses which forms the code vector from the importance pulse removing section(1150).