www.gusucode.com > 语音信号处理工具箱 - Voicebox源码程序 > Voicebox\lpcar2rf.m
function rf=lpcar2rf(ar) %LPCAR2RF Convert autoregressive coefficients to reflection coefficients AR=(RF) % % Input: ar(:,p+1) Autoregressive coefficients % Output: rf(:,p+1) Reflection coefficients with rf(:,1)=1 % Copyright (C) Mike Brookes 1997 % % Last modified Fri Dec 3 15:21:40 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(ar); if any(ar(:,1)~=1) ar=ar./ar(:,ones(1,p1)); end rf = ar; w=ones(nf,1); for j = p1-1:-1:2 k = rf(:,j+1); d = (1-k.^2).^(-1); wj=ones(1,j-1); rf(:,2:j) = (rf(:,2:j)-k(:,wj).*rf(:,j:-1:2)).*d(:,wj); end