Pulse combination codebook searching method for sound signal encoding - preselecting sound related pulse combination subset and searching within that subset

摘要

The pulse combination codebook searching method involves a series of parameter being derived by the spectrum analyser (102) and the filter responses characteriser (105) for each sample (S). The pitch extractor (104) obtains further data following processing by the whitening filter (103). Processing by the perceptual filter (107), the backward filter (108) and the long term predictor (106) enables the amplitude selector (112) to restrain the code vectors being searched by the optimising controller (109), to those which are most promising. Parameters for the final selection are converted into digital channel format by the multiplexer (111), for entry into the dynamic codebook.