METHOD FOR PREDICTIVE-LINKED QUANTIZATION FOR SPLIT LSF VECTORS

摘要

PURPOSE: A method for predictive-linked quantization for split LSF vectors is provided to realize a low mean SD(Spectral Distortion) and improve an outlier percentage. CONSTITUTION: A first quantizer(30) quantizes middle LSF(Line Spectrum Frequencies) vectors for generating the quantized middle LSF vectors and an index 1. A first classifier(32) inputs the first middle LSF vector for deciding an appropriate codebook out of three COLs. A second classifier(34) inputs the first middle LSF vector for deciding an appropriate codebook out of three COUs. A second quantizer(36) encodes lower LSF vectors by using the codebook decided by the first classifier for generating an index 2. A third quantizer(38) encodes upper LSFs by using the codebook decided by the second classifier for generating an index 3.