clear all;
s = wavread('sentence.wav');
fs = 16000;

%compression Rate
for L = 0 : 4
   b = L * 25;
%b=input('Enter the Compression Rate Required\n');

% Choosing the Window Length
l = length(s);
s = s';
samples = ceil(l * (1+b/100));
diff = abs(samples - l);
d = diff;

if b > 0
   for j = samples: -ceil(samples/d) : 5
      for i = 1 : (ceil(samples/d)-1)
         sent(1,(j+1-i)) = s(1,(j+1-i-diff));
      end
   	sent(1,(j-i)) = sqrt((s(1,(j-(diff+1)-i))^2 + s(1,(j-(diff-1)-i))^2)/2);
   	diff = diff -1;
   end
elseif b < 0
   ele = 0;
   for j = 1 : ceil(samples/d) : samples
      for i = 1 : ceil(samples/d)
         sent(1,(j+1-i)) = s(1,(j+1-i+ele));
      end
   	ele = ele + 1;
   end
elseif b == 0
   for i = 1 : samples
      sent(1,i) = s(1,i);
   end

end

% a=input('Enter the starting sample number\n');
% Choosing the speech segment
a = 2500;
s1=sent(a:a+3000);
% Smoothing it with a window
s2=conv(hamming(100),s1);
% Finding the Average magnitude difference function
for k=1:length(s2)-1
   d(k)=0;
   for n=k+1:length(s2)
      d(k)=d(k)+(s2(n)-s2(n-k));
   end
end
%figure(2);
%plot(d);
%title('The AMDF function plot for the chosen speech segment');
%xlabel('Samples');
j=1;
% Finding the minimum points to calculate the pitch
for i=1:length(d)/2
   if d(i+1)<d(i) & d(i+1)<d(i+2)
      p(j)=i+1;
      j=j+1;
   end
end   
period=0;
for i=1:length(p)-1
   period=period+(p(i+1)-p(i));
end
period=period/(length(p)-1);
pitch=fs/period  
end;