function [Fs, xr, bits, x] = encode(x, filename, start, stop, quantType, outFileBefore, outFileAfter)

% use this sampling frequency and bits if not specified
Fs = 44100;
bits = 16;
totalBits = 0;

% if user gave a filename, read the file in
if ~isempty(filename)
   [xFile,Fs,bits] = wavread(filename);
   xFile = transpose(xFile);
   if (start == -1)
      x = xFile;
   else      
      x = xFile(start:stop);
   end   
end

% build array of frequencies
FFTLength = 512;
f=[1:FFTLength/2]*(Fs/FFTLength);

% set number of filters
M = 32;

% set filter length;
L = 2*M;

w = zeros(1,L);
h = zeros(M,L);
g = zeros(M,L);

xr = zeros(1,length(x));

% define the low-pass window
for n = 1:L
   w(1,n) = sin((pi/(2*M))*(n - 1 + 0.5));
end

for k = 1:M	
   %compute analysis and synthesis filters
   for n = 1:L
      h(k,n) = w(n)*sqrt(2/M)*cos(((2*(n - 1) + M + 1) * (2*(k - 1) + 1) * pi)/(4*M));
   	g(k,L - n + 1) = h(k,n);   
   end
end

start = 1;
count = 1;

% window the signal into FFTLength frames
while (start <= (length(x) - FFTLength + 1))
	count
   count = count + 1;   
   % window the input
   xF = x(start:start + FFTLength - 1);
   
   %find the masking threshold for the window
   thres = findThreshold(xF, FFTLength, f, bits);
   
   % send the signal into the filter banks
   [filtered, totalBits] = filterBanks8(xF,'',0,0, h, g, Fs, bits, f, thres, FFTLength, totalBits, quantType);
   
   % build up final reconstructed signal
   xr(start:start + FFTLength - 1) = xr(start:start + FFTLength - 1) + filtered;
   
   start = start + FFTLength - FFTLength/16;

end

figure;
%plot original and reconstructed signals
subplot(2,1,1),plot(x,'b');
subplot(2,1,2),plot(xr,'r');

figure;
%plot FFTs of original and reconstructed signals
subplot(2,1,1),plot(abs(fft(x)),'b');
subplot(2,1,2),plot(abs(fft(xr)),'r');

figure;
% plot FFT error
plot(abs(fft(x)) - abs(fft(xr)));

if ~isempty(outFileBefore)
   outFileBefore = strcat('demo\', outFileBefore);
end

if ~isempty(outFileAfter)
   outFileAfter = strcat('demo\', outFileAfter);
end

% calculate compression ratio
bitsBefore = length(x) * bits
bitsAfter = totalBits
percent = bitsAfter / bitsBefore * 100

% write wave files to disk

if ~isempty(outFileBefore)
   wavwrite(x, Fs, bits, outFileBefore);
end

if ~isempty(outFileAfter)
   wavwrite(xr, Fs, bits, outFileAfter);
   
   fid = fopen(strcat(outFileAfter, '.txt'),'w');
   fprintf(fid, 'Before: %d\nAfter: %d\nPercent: %f', bitsBefore, bitsAfter, percent);
   fclose(fid);
end