%信号采样
>> [x,fs,bits]=wavread('C:\Users\20080119\Desktop\kaimen.wav');
>> ts=1/fs;
>> t=0:ts:(length(x)-1)/fs;
>> plot(t,x);
>> xlabel('时间');ylabel('语音信号');title('信号采样');
%量化
>> y=x(:,1);
>> w=juny(y,1,64);
>> n=length(y);
>> t=1:1:n;
>> plot(t,w);
>> xlabel('时间');ylabel('量化幅值');title('量化后波形');
%预加重
>> N=1024;
>> df=fs/N;
>> f=(0:N-1)*df;
>> r=fft(y,1024);
>> [h1,f1]=freqz([1,-0.95],[1],8000);
>> u=r*h1'
>> u2=abs(u);
>> u3=20*log10(u2);
>> yuanlai=20*log10(abs(r));
>> plot(f,yuanlai,f,u3);
>> xlabel('频率/Hz');ylabel('幅度/dB');title('滤波前后语音信号频谱');
%量化子程序
%juny.m
function h=juny(f,v,l)
n=length(f);
t=2*v/l;
p=zeros(1,l+1);
for i=1:l+1
p(i)=-v+(i-1)*t;
end
for i=1:n
if f(i)>v
h(i)=v;
end
if f(i)<=-v
h(i)=-v;
end
flag=0;
for j=2:l/2+1
if(flag==0)
if(f(i)<p(j))
h(i)=p(j-1);
flag=1;
end
end
end
for j=l/2+2:l+1
if(flag==0)
if(f(i)<p(j))
h(i)=p(j);
flag=1;
end
end
end
end
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