%Daniel Linnen
%HW1

clear all;
%declaring counting variables
l=1;
m=1;
count=1;
%initializing values to zero
h1=0;
x1=0;
xn=0;
sn=0;
dn=0;
Pxr=0;
Pdr=0;
echo=0;
Pxe1=0;
Pde1=0;
%declaring files
f1=fopen('C:\ELE 498D\testw.dat', 'r');
f2=fopen('C:\ELE 498D\test1.dat', 'r');
%initializing arrays
x=zeros(105,1);
h=[-0.01,-0.05,0.1,0.3,0.2,-0.1,0.05,0.01];
%end of declaration

%start of program
while(count==1)
    %reading files
    [xn,count] = fread(f1, 1, 'short');
     if(count==0)
        break;
    end   
    [sn,count] = fread(f2, 1, 'short');
    
    l=l+1;
    %converting to integers
    xn = xn/32768;
    sn = sn/32768;
    %update the input buffer
    
    for i=105:-1:2
        x(i)=x(i-1);
    end %end for
    
    x(1)=xn;
    echo=0;
    %convolution (to make the echo)
    
    for i=98:105
        h1=h(i-97);
        x1=x(i);
        echo = echo + h(i-97)*x(i);
        
    end %end for
    
    %combining talker2's voice with echo, the only signal we have access too
    dn = echo + sn;
    
    %exponential
    Pxe1=0.95*Pxe1+(1-0.95)*xn*xn;
    
    Pde1=0.95*Pde1+(1-0.95)*dn*dn;
    Pdr=Pdr+dn*dn;
    Pxr=Pxr+xn*xn;
    
    %rectangular
    if(l==65)        
        Pxe(m) = 10*log10(Pxe1);
        Pde(m) = 10*log10(Pde1);
        Pxrw(m) = 10*log10(Pxr/64);
        Pdrw(m) = 10*log10(Pdr/64);
                m=m+1;
                pxr=0;
                pdr=0;
                Pxe1=0;
                Pde1=0;
                l=1;
    end %end if
end % end while

%% plotting
figure(1) 
plot(Pxrw, 'r')
hold
plot(Pdrw, 'b')
figure(2)
plot(Pxe, 'r')
hold
plot(Pde, 'b')