l4

function []=lab4(input,output,amp, freq)
info=audioinfo(input);
[y,fs]=audioread(input);
% step=1/fs;
% duration=info.Duration;
% t=0:step:duration;
% time=t(1:end-1);
% transposed_time=transpose(time);
subplot(3,1,1);
plot(y(1:1000));
title('input');
fm=freq/fs;
arg=2*pi*fm;
 for i=1:length(y)
     modulator(i)=(1+amp*sin(arg*i));
     y_out(i)=modulator(i)*y(i);
     %y(i)=(1+amp*sin(arg*i))*y(i);
 end
subplot(3,1,2);
plot(modulator(1:1000));
title('modulator');
subplot(3,1,3);
plot(y_out(1:1000));
title('output');
audiowrite(output,y_out,fs);
end