path1.m

这是一个用于语音信号处理的工具箱

%PATH1 : Path I's Frame match by Dynamic time warping.
%FUNCTION: [m,adis]=path1(cofa1,cofa2,speech2,basic,show);
% 
%Input  cofa1 = linear prediction coefficient matrix for speech1.
%       cofa2 = linear prediction coefficient matrix for speech2.
%       speech2 = source speech
%       basic = [measure constraint path order fram_len over_len lens], the 
%                basic parameters.
%       show = display the searching process if show == 1
%
%Output   m = Dynamic time warping function i-->w, w=m(i)
%         adis = final accumulated distance
%
%Please see page 211 of "fundamentals of speech recogniction" by Rabiner 
%       and Juang for this local constraints and the resulting path.
% 

function [m,adis]=path1(cofa1,cofa2,speech2,basic,show);
% variables used in the function:
%       i = index for cofa1.
%       j = index for cofa2.
%       M = number of frames for cofa2.
%       N = number of frames for cofa1.
%       path = possible path, [accumulated distances, i_moving, j_jump....]
%       p_path = path matrix of previous frame
%       t_path = path of the current point

%%%%%%%%% PLEASE DO NOT EDIT THE FOLLOWING   %%%%%%%%%%%

speech2=speech2(:)';  % convert to row vector 
[N dummy]=size(cofa1);
[M dummy]=size(cofa2);

%retrieve the basic parameters
measure=basic(1);
path_const=basic(3);
order=basic(4);
fram_len=basic(5);
over_len=basic(6);
lens=basic(7);
%%%%%%%%%%%%%%% FINDING the OPTIMAL PATH by Dynamic Programming

%%%%%%% construct the distortion measure matrix

for i=1:N
   for j=1:M
        a=cofa1(i,:);
        b=cofa2(j,:);
        test=speech2( (j-1)*lens+order+1:j*lens+order );
        zi=speech2( (j-1)*lens+1: (j-1)*lens+order );
        DIS(i,j)=distance(a,b,test,zi,measure);
   end
end

NM=2*N+2*M+1;
path=ones(M, NM);
path=-1*path;

%%%%%%% Initial condition, first frame
i=1;
j=1;
    path(j,1)=DIS(i,j);
for j=2:M
    t_path=path(j-1,:);
    t_path=t_path(t_path>-1);
    t_path=[t_path 0 1];
    t_path(1)=DIS(i,j)+path(j-1,1);
    path(j,1:length(t_path))=t_path;
end

%%%%%%% runing from 2nd frame to the end
for i=2:N

    p_path=path; % the path matrix of previous frame

    j=1;
        % there is only one path to reach this (i,1) point
        t_path=p_path(j,:);
        t_path=t_path( t_path>-1 );
        t_path=[t_path 1 0];
        t_path(1)=t_path(1)+DIS(i,j);
        path(j,1:length(t_path))=t_path;
    
    for j=2:M

        % there are three path to this current (i,j) point
        dis(1)=p_path(j,1)+0.5*DIS(i,j);
        dis(2)=p_path(j-1,1);
        dis(3)=path(j-1,1)+0.5*DIS(i,j);
        [dummy,indx]=sort(dis);

        if indx(1)==1
           t_path=p_path(j,:);
           t_path=t_path(t_path>-1);
           t_path=[t_path 1 0];
 
        elseif indx(1)==2
           t_path=p_path(j-1,:);
           t_path=t_path(t_path>-1);
           t_path=[t_path 1 1];
  
        elseif indx(1)==3
           t_path=path(j-1,:);
           t_path=t_path(t_path>-1);
           t_path=[t_path 0 1];
        end
        
        t_path(1)=dummy(1)+DIS(i,j);
        nl=length(t_path);
        path(j, 1:nl)=t_path;
        fdis(j)=path(j,1);
        % delete the remaining path
        if (nl+1)<NM & path(j,nl+1)~=-1
              path(j,nl+1:NM)=-1*ones(1,NM-nl);
        end

    end
    clear p_path;

    if show==1
       idx=find( fdis>0 );
       [dum,idxidx]=min( fdis(idx) );
       tmpath=path(idx(idxidx),:);
       tmpath=tmpath(tmpath>-1);
       x=[1 tmpath(2:2:length(tmpath))];
       y=[1 tmpath(3:2:length(tmpath))];
       plot(integ(x),integ(y),'+');
       axis([1 N 1 M]);
       title('Finding the optimal path!');
       drawnow;       
       fdis=zeros(1,M);
    end

end

t_path=path(M,:); % final path!
t_path=t_path(t_path >-1);
x=[1 t_path(2:2:length(t_path))];
y=[1 t_path(3:2:length(t_path))];
adis=t_path(1,1);
x=integ(x);
y=integ(y);

% check the final x-axis since (0,1) path is legal

if length(x)>N

   len=length(x);
   i=1;
   while len>N
      i=i+1;
      if ( x(i)-x(i-1) )==0
         x(i-1)=[];
         y(i-1)=[];
         i=i-1;
         len=len-1;
      end  
   end
end

m=[x;y];
if show==1
   plot(x,y,'k+')
   xlabel('target')
   ylabel('source')
end