Matlab【特征提取】基于一帧数据倒谱法、LPC内插法、LPC求根法实现语音共振峰提取含Matlab源码.zip

function [k,v]=findpeaks(x,m,w) %FINDPEAKS finds peaks with optional quadratic interpolation [K,V]=(X,M,W) % % Inputs: X is the input signal (does not work with UInt datatype) % M is mode: % 'q' performs quadratic interpolation % 'v' finds valleys instead of peaks % W is the width tolerance; a peak will be eliminated if there is % a higher peak within +-W samples % % Outputs: K are the peak locations in X (fractional if M='q') % V are the peak amplitudes: if M='q' the amplitudes will be interpolated % whereas if M~='q' then V=X(K). % Outputs are column vectors regardless of whether X is row or column. % If there is a plateau rather than a sharp peak, the routine will place the % peak in the centre of the plateau. When the W input argument is specified, % the routine will eliminate the lower of any pair of peaks whose separation % is <=W; if the peaks have exactly the same height, the second one will be eliminated. % All peak locations satisfy 1<K<length(X). % % If no output arguments are specified, the results will be plotted. % % Copyright (C) Mike Brookes 2005 % Version: $Id: findpeaks.m,v 1.5 2010/10/28 10:41:16 dmb Exp $ % % VOICEBOX is a MATLAB toolbox for speech processing. % Home page: 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 % http://www.gnu.org/copyleft/gpl.html or by writing to % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% if nargin<2 m=' '; end nx=length(x); if any(m=='v') x=-x(:); % invert x if searching for valleys else x=x(:); % force to be a column vector end dx=x(2:end)-x(1:end-1); r=find(dx>0); f=find(dx<0); if length(r)>0 & length(f)>0 % we must have at least one rise and one fall dr=r; dr(2:end)=r(2:end)-r(1:end-1); rc=repmat(1,nx,1); rc(r+1)=1-dr; rc(1)=0; rs=cumsum(rc); % = time since the last rise df=f; df(2:end)=f(2:end)-f(1:end-1); fc=repmat(1,nx,1); fc(f+1)=1-df; fc(1)=0; fs=cumsum(fc); % = time since the last fall rp=repmat(-1,nx,1); rp([1; r+1])=[dr-1; nx-r(end)-1]; rq=cumsum(rp); % = time to the next rise fp=repmat(-1,nx,1); fp([1; f+1])=[df-1; nx-f(end)-1]; fq=cumsum(fp); % = time to the next fall k=find((rs<fs) & (fq<rq) & (floor((fq-rs)/2)==0)); % the final term centres peaks within a plateau v=x(k); if any(m=='q') % do quadratic interpolation b=0.5*(x(k+1)-x(k-1)); a=x(k)-b-x(k-1); j=(a>0); % j=0 on a plateau v(j)=x(k(j))+0.25*b(j).^2./a(j); k(j)=k(j)+0.5*b(j)./a(j); k(~j)=k(~j)+(fq(k(~j))-rs(k(~j)))/2; % add 0.5 to k if plateau has an even width end % now purge nearby peaks if nargin>2 j=find(k(2:end)-k(1:end-1)<=w); while any(j) j=j+(v(j)>=v(j+1)); k(j)=[]; v(j)=[]; j=find(k(2:end)-k(1:end-1)<=w); end end else k=[]; v=[]; end if any(m=='v') v=-v; % invert peaks if searching for valleys end if ~nargout if any(m=='v') x=-x; % re-invert x if searching for valleys ch='v'; else ch='^'; end plot(1:nx,x,'-',k,v,ch); end