clear all
close all

plat = 'octave'; %put either 'octave' or 'matlab'

if (plat == 'matlab')
  [s,Fs]=wavread('clarinetto.wav');
else
  [s,Fs]=auload('clarinetto.wav');
end;

t=[0:1/Fs:length(s)/Fs-1/Fs]';

%16-bit quantization
nbits=16;
q=2/(2^nbits-1)
s_16=q*quantize(s./q);

viz_frame=[10000:11000];
figure(2)
subplot(2,1,1)
plot(viz_frame,s(viz_frame))
title('Original sample')

%quantizz. 
nbits=7;
q=2/(2^nbits-1)
s_q=q*quantize(s./q);
subplot(2,1,2)
plot(viz_frame,s_q(viz_frame),'b')
title('Quantized sample (8 bits)')


%companding
mu=255;
V=0.2; %max(abs(s));
s_compr=f_mulaw(s,mu,V);

%quantizz. 
nbits=8;
q=2/(2^nbits-1)
s_compr_q=q*quantize(s_compr./q);
subplot(2,1,2)

%inv companding
s_decompr_q=f_invmulaw(s_compr_q,mu,V);

subplot(2,1,2)
hold on;
plot(viz_frame,s_decompr_q(viz_frame),'r--')
title('Quantized sample (8 bits, red: mu-law)')

hold off;

if (plat == 'matlab') 
  wavwrite(s_q,Fs,16,'s_q.wav');
  wavwrite(s_decompr_q,Fs,16,'s_qmulaw.wav');
else
  ausave('s_q.wav',s_q,Fs,'short');
  ausave('s_qmulaw.wav',s_decompr_q,Fs,'short');
end