[x fs]=wavread('8.wav');bank=melbankm(24,256,fs,0,0.4,'t');%Mel滤波器的阶数为24,fft变换的长度为256,采样频率为16000Hz%归一化mel滤波器组系数bank=full(bank);bank=bank/max(bank(:));for k=1:12 %归一化mel滤波器组系数n=0:23;dctcoef(k,:)=cos((2*n+1)*k*pi/(2*24));endw=1+6*sin(pi*[1:12]./12);%归一化倒谱提升窗口w=w/max(w);%预加重滤波器xx=double(x);xx=filter([1-0.9375],1,xx);%语音信号分帧xx=enframe(xx,256,80);%对x 256点分为一帧%计算每帧的MFCC参数for i=1:size(xx,1)y=xx(i,:);s=y'.*hamming(256); t=abs(fft(s));%fft快速傅立叶变换t=t.^2; c1=dctcoef*log(bank*t(1:129));c2=c1.*w';m(i,:)=c2';end%求取一阶差分系数dtm=zeros(size(m));for i=3:size(m,1)-2dtm(i,:)=-2*m(i-2,:)-m(i-1,:)+m(i+1,:)+2*m(i+2,:);enddtm=dtm/3;%求取二阶差分系数dtmm=zeros(size(dtm));for i=3:size(dtm,1)-2dtmm(i,:)=-2*dtm(i-2,:)-dtm(i-1,:)+dtm(i+1,:)+2*dtm(i+2,:);enddtmm=dtmm/3;%合并mfcc参数和一阶差分mfcc参数ccc=[m dtm dtmm];%去除首尾两帧,因为这两帧的一阶差分参数为0ccc=ccc(3:size(m,1)-2,:);ccc% subplot(2,1,1) % ccc_1=ccc(:,1);% plot(ccc_1);title('MFCC');ylabel('幅值');% [h,w]=size(ccc);% A=size(ccc);% subplot(212) % plot([1,w],A);% xlabel('维数');% ylabel('幅值');% title('维数与幅值的关系')
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