init.m

the implement of the encoder and the decoder of the CELP

global h len pcbsize szsubf subvec nzero numsubv scalor descalor sub_cnt frm_num
global frames pdmin pdmax shiftrange olpc former curr twelfth minv maxv b_hpf a_hpf d_hpf1 a_lpf b_lpf d_lpf1
global FirstComp dlysize dlyml dlymh dfrac wsinc syn_e0 pbuf lbuf gamma1 nsubf gamma2 codebook_lpc
global bpa bla bra bwa bpb blb brb bwb pdelay intp gamma nfrac frange del_intv frame_count
global pcode pgain cindex cgain TRUE FALSE prev pdlyindx lpcMat lpcword

len=30;                              % length of truncated convolution
pcbsize=256;                         % length of pitch delay book
frames=240;                          % Size of frame
szsubf=60;                           % Size of subframe
nsubf=frames/szsubf;                 % Number of subframe per frame
subvec=20;                           % Size of subvector in each subframe
numsubv=szsubf/subvec;               % Number of subvector in each subframe
nzero=4;                             % Number of non-zero in each subvector
pdmin=20;                            % Min pitch delay
pdmax=147;                           % Max pitch dealy
shiftrange=64;                       % Delta search range
frange=6;                             % fractional search range
intp=128;                            % Number of integer delay (128)
scalor=10e2;                          % Scaler of input speech data;
descalor=10e-2;                       % Descaler of input speech data;
minv = zeros( 1, frames ) - 32768;   % Maximum allowed speech sample value
maxv = zeros( 1, frames ) + 32767;   % Minimum allowed speech sample value
b_hpf = [ 0.940, -1.879, 0.940 ];    % Design of pre-process filter: HPF @ 100 HZ 
a_hpf = [ 1.0, -1.932595, 0.935420 ]; 
d_hpf1 = zeros( 2, 1 );

sub_cnt=0;                           % Overall count of sub-frame
former=zeros(frames,1);
TRUE = 1;                            % Flag 
FALSE = 0;
olpc=10;                             % Order of lpc filters

bpa = zeros( 1, intp+szsubf+pdmin-1 );        % Pitch memory for 1/P(z)
bpb = zeros( 1, intp+szsubf+pdmin-1 );        % Pitch memory for 1/P(z)
bla = zeros( 1, olpc );                 % Spectrum memory for 1/A(z)
blb = zeros( 1, olpc );                 % Spectrum memory for 1/A(z)
bra = zeros( 1, olpc );                 % Spectrum memory for A(z)
brb = zeros( 1, olpc );                 % Spectrum memory for A(z)
bwa = zeros( 1, olpc );                 % Spectrum memory for 1/A(z/gamma)
bwb = zeros( 1, olpc );                 % Spectrum memory for 1/A(z/gamma)
pdelay = zeros(1, intp+szsubf+pdmin-1 ); % Pitch delay buffer for codebook

pcode=[];                               % Pitch codeword matrix
pgain=[];                               % Pitch gain matrix
cindex=[];                               % Excitation codeword
cgain=[];                               % Excitation gain matrix
lpcMat=[];
prev=0;                                 % Used in delta search to record the last pitch code
load('pdlyindx.dat');                   % Load pitch delay table (Uniform integer delay and non-uniform fractional delay)
pdlyindx=reshape(pdlyindx',1,size(pdlyindx,1)*size(pdlyindx,2));
gamma1=0.8;                           % Weighting factor (0.8)
gamma2=0.99413;
frm_num=0;
former=zeros(1,frames);              % Used in analysis for buffering former sub-frame
curr=zeros(1,frames);                % Used in analysis for buffering current sub-frame
dlysize=40;                          % Length of interpolation interval, in samples
dlyml=-20;                           % Start of interpolation interval
dlymh=19;                            % End of interpolation interval
wsinc=zeros(nfrac,dlysize);          % Memory storing weighted sinc values
dfrac=[0.25,0.33333333,0.5,0.66666667,0.75]; % Fractional delays
FirstComp=TRUE;                      % Flag of computing weighted sinc
nfrac=5;                             % Number of fractional delays
syn_e0=zeros(1,frames);              % synthesized white noise like error signal 
pbuf=zeros( 1, intp+szsubf+pdmin-1 );      % Pitch buffer used in synthesis
lbuf=zeros(1,olpc);                  % LPC buffer used in synthesis
twelfth=[3,4,6,8,9];                 % Fractional delays for hamming window
del_intv=2;                          % Interval defined by Pitch delta search (2 or 4)

% Initialize variables used in postfilter
global Ycg y59save y60save Engcg cbindx cbgbk ALPHA BETA TC ipZ opZ

ALPHA=0.8;
BETA=0.5;
TC=0.01;
ipZ=0;
opZ=0;