mfcc.zip

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%% MFCC %%%%%%%%%%%%%%%% function feature =mfcc(x,Fs) %读取语音操作 %声音读取,Fs为采样率 %[x,Fs] = audioread('1.wav'); %语音预处理H(z)=1-uz^(-1) z=filter([1 -0.9735], 1, double(x)); %分帧加窗 num=16/1000*Fs; %取窗大小，16ms:256 yframe=enframe(z,num,num/2); %enframe实现分帧 [row,col]=size(yframe); %一帧col个点，一共row帧 window1=hamming(num);%汉明窗 yframe1=yframe.*window1; %每一帧信号加汉明窗 %% 三角滤波器组 fs=Fs; fl=0; fh=fs/2; bl=1125*log(1+fl/700);%将频率转换为Mel频率 bh=1125*log(1+fh/700); p=26;%滤波器个数 nfft=num;%FFT点数 B=bh-bl; y=linspace(0,B,p+2);%产生0到B之间p+2个数 Fb=700*(exp(y/1125)-1);%将Mel频率转换为频率 W2=nfft/2+1;%fs/2内对应的FFT点数 df=fs/nfft; freq=(0:W2-1)*df;%采样频率值 bank=zeros(26,W2);%生成一个26行W2列的全零数组 for k=2:p+1%why从2开始？因为k-1 f1=Fb(k-1); f2=Fb(k+1); f0=Fb(k); n1=floor(f1/df)+1; n2=floor(f2/df)+1; n0=floor(f0/df)+1; for i=1 : W2 if i>=n1 & i<=n0 bank(k-1,i)=(i-n1)/(n0-n1); elseif i>n0 & i<=n2 bank(k-1,i)=(n2-i)/(n2-n0); end end end %傅里叶变换计算频谱，求出功率谱 yf=zeros(row,col); for i=1:row yf(i,:)=fft(yframe1(i,:),num); mag(i,:)=abs(yf(i,:)); power(i,:)=mag(i,:).*mag(i,:); power_bank(i,:)=bank*power(i,1:201)'; log_mag1(i,:)=log10(power_bank(i,:)); end %DCT for i=1:row d(i,:)=dct(log_mag1(i,:)); %i指帧,即一行是一帧 end d(any(isnan(d)'),:)=[]; %去掉所有含NaN的帧 feature=(d(:,1:13))';