segment.m

这是一个用于语音信号处理的工具箱

% Function: preform Segmentation based on a spectral stability criterium.

function seg=segment(signal,basic,threshold);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%                                                         %%
%%%%%%%  Segmentation baased on a spectral stability criterium  %%
%%%%%%%                                                         %%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 % The first step produces the following variables:
 %	nframe = number of frames.
 %	ntotal = number of samples.

%retrieve the basic specification
F_len=basic(5);
O_lap=basic(6);
M_len=F_len-O_lap;


ntotal=length(signal); 
nframe=floor(ntotal/M_len);
signal=signal(1: (nframe*M_len) );

% first frame analysis
sso=signal(1:F_len);
spec1=abs(fft(sso,128));
seg=[];
counter=1;
for k=2:nframe-1
	sso=signal((k-1)*M_len+1:k*M_len+O_lap);
   spec2=abs(fft(sso,128));
   distance(k)=sum((spec1-spec2).^2)/sum(spec1.^2);
   if distance(k)>=threshold
      seg(counter)=k-1;
      counter=counter+1;
   end   
   spec1=spec2;
end
%we don't want one period segments
seg1=diff(seg);
seg2(1)=seg(1);
counteraux=2;
for auxidx=1:length(seg1)  
   if(seg1(auxidx)>2)
      seg2(counteraux)=seg(auxidx);
      seg2(counteraux+1)=seg(auxidx+1);
      counteraux=counteraux+2;
   end
end
seg=[seg2 seg(length(seg))];
seg=[seg(abs(diff(seg))>1) seg(length(seg))];