gusucode.com > 语音信号处理工具箱 - Voicebox源码程序 > Voicebox\lpcrr2ar.m
function [ar,e]=lpcrr2ar(rr); %LPCRR2AR convert autocorrelation coefs to ar coefs [AR,E]=(RR) %E is the residual energy % could test e each time and remove rows when it gets small % Copyright (C) Mike Brookes 1997 % % Last modified Fri Dec 3 16:10:02 1999 % % VOICEBOX is a MATLAB toolbox for speech processing. Home page is at % http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License as published by % the Free Software Foundation; either version 2 of the License, or % (at your option) any later version. % % This program is distributed in the hope that it will be useful, % but WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the % GNU General Public License for more details. % % You can obtain a copy of the GNU General Public License from % ftp://prep.ai.mit.edu/pub/gnu/COPYING-2.0 or by writing to % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% [nf,p1]=size(rr); p=p1-1; ar=ones(nf,p1); ar(:,2) = -rr(:,2)./rr(:,1); e = rr(:,1).*(ar(:,2).^2-1); for n = 2:p k = (rr(:,n+1)+sum(rr(:,n:-1:2).*ar(:,2:n),2)) ./ e; ar(:,2:n) = ar(:,2:n)+k(:,ones(1,n-1)).*ar(:,n:-1:2); ar(:,n+1) = k; e = e.*(1-k.^2); end e=-e;