preprocess.asv

该代码实现了am

clear all
filename='a1.wav'
[S00]=wavread(filename);
figure
subplot(3,1,1),plot(S00);title('信号采集')                                                    %display the waveform which loaded

n0=size(S00,1);
S01(1,1)=0;
B=[1,-32735*2^(-15)];
A=[1,-1];
n=2:n0;
S01(n,:)=filter(B,A,S00(n,:)) ;                       %setover compensation

B=1;
A=[1,-28180*2^(-15)];
S0(n,:)=filter(B,A,S01(n,:)) ;                            %pre_aggravation

for k=1:n0/160
    S(k,:)=S0(1+(k-1)*160:k*160);
end                                                           %frame divide



s=S(22,:);
[a,g]=lpc(s,8);
K=dir2latc_mtlb(a);
r=K(2:9);


for i=1:8
    if abs(r(1,i))<0.675  
         LAR(1,i)=r(1,i);
      elseif abs(r(1,i))>=0.675 & abs(r(1,i))<0.950
         LAR(1,i)=sign(r(1,i))*(2*abs(r(1,i))-0.675);
      elseif abs(r(1,i))>=0.950 & abs(r(1,i))<=1.000
         LAR(1,i)=sign(r(1,i))*(8*abs(r(1,i))-6.375);
      end
  
      A=[20 20 20 20 13.637 15 8.334 8.824];
      B=[0 0 4 -5 0.184 -3.5 -0.666 -2.235];
      temp(1,i)=A(1,i).*LAR(1,i)+B(1,i);
      LARc(1,i)=fix(temp(1,i)+sign(temp(1,i))*0.5);
end
  


for i=1:8
LARpp(1,i)=(LARc(1,i)-B(1,i))./A(1,i);
end
LARpppre=LARpp;
LARppp(1,:)=0.75*LARpppre+0.25*LARpp(1,:);
LARppp(2,:)=0.5*LARpppre+0.5*LARpp(1,:);
LARppp(3,:)=0.25*LARpppre+0.75*LARpp(1,:);
LARppp(4,:)=LARpp(1,:);


for k=1:4
    for i=1:length(LARppp)
	if 	abs(LARppp(k,i))<0.675
		rp(k,i)=LARppp(k,i);
	elseif 	abs(LARppp(k,i))>=0.675 & abs(LARppp(k,i))<1.225
		rp(k,i)=sign(LARppp(k,i))*(0.500*abs(LARppp(k,i))+0.337500);
	elseif	abs(LARppp(k,i))>=1.225 & abs(LARppp(k,i))<=1.625
		rp(k,i)=sign(LARppp(k,i))*(0.125*abs(LARppp(k,i))+0.796875);
	end
end
end

[d(1:13),tt]=latcfilt([1,rp(1,:)],s(1:13));
[d(14:27),tt]=latcfilt([1,rp(2,:)],s(14:27));
[d(28:40),tt]=latcfilt([1,rp(3,:)],s(28:40));
[d(41:160),tt]=latcfilt([1,rp(4,:)],s(41:160));
d22=d;
clear d