subcoding.m

the implement of the encoder and the decoder of the CELP

function syn_e0=subcoding(subf,lpc_eff)

global bpa bla bra bwa bpb blb brb bwb 
global szsubf TRUE FALSE

sube1=zeros(1, szsubf);

% Find first initial error (pitch+stochastic excitation). Returned with sube1
[bpa, bla, bra, bwa, sube1]=initsub(subf, sube1, szsubf, bpa, bla, bra, bwa,FALSE); 

bla=blb;
bra=brb;                                    % Update buffer
bwa=bwb;

impulse(szsubf, lpc_eff);                   % Generate impulse response of weighting filter 1/A(z/gamma)

psearch(sube1);                             % Pitch search routine

sube0=zeros(1, szsubf);                     

% Find second initial error (stochastic excitation). Returned with sube0
[bpa,bla,bra,bwa,sube0]=initsub(subf, sube0, szsubf, bpa, bla, bra, bwa,TRUE);

[syn_e0]=cbsearch(sube0);                   % Stochastic excitation search

% Update pitch filter memory with synthesized pitch. Update 1/A(z), A(z), and 1/A(z/gamma)
[bpb,blb,brb,bwb,sube0]=initsub(subf, syn_e0, szsubf, bpb, blb, brb, bwb,TRUE);

bpa=bpb;
bla=blb;
bra=brb;
bwa=bwb;