clear all
close all
close all hidden
clc
fid=fopen('THEOTH.mp3','r');
m=fread(fid,'int16');
count=8500;
Mp=max(m);
Fs=8000;
Ts=1;
No_samples=(2*Fs)+Ts;
time=[1:Fs/64];
bits=5;
levels=2^bits;
bit_rates=Fs*bits
alpha=0.45;
diff_sig(1)=m(1);
for k=2:count;
    diff_sig(k)=m(k)-alpha*m(k-1);
end
step_size=(2*Mp)/levels;
for k=1:No_samples
    samp_in(k)=m(k*Ts)
    quant_in(k)=samp_in(k);
    error(k)=(samp_in(k)-quant_in(k));
end
sings=sign(m);
quant_out=quant_in;
for i=1:count
    s(i)=abs(quant_in(i))+0.5;
    quant_out(i)=signs(i)*round(s(i))*step_size;
end
%decoding
s_out=quant_out;
s_out(1)=quant_out(1);
for k=2:count
    s_out(k)=quant_out(k)-alpha(k)*s_out(k-1);
end
SNR=1.5(levels^2);
SNR_db=10*log10(SNR);
subplot(4,1,1);
plot(time,m(time),time,s_out(time),'r');speech
title('input signal')
x.label('Time');
y.label('m(t)');
grid on;