sy2.zip_DFT_LPC谱包络_倒谱 lpc_倒谱 包络_共振峰

function [f,t]=enframe(x,win,inc) %ENFRAME split signal up into (overlapping) frames: one per row. [F,T]=(X,WIN,INC) % % F = ENFRAME(X,LEN) splits the vector X(:) up into % frames. Each frame is of length LEN and occupies % one row of the output matrix. The last few frames of X % will be ignored if its length is not divisible by LEN. % It is an error if X is shorter than LEN. % % F = ENFRAME(X,LEN,INC) has frames beginning at increments of INC % The centre of frame I is X((I-1)*INC+(LEN+1)/2) for I=1,2,... % The number of frames is fix((length(X)-LEN+INC)/INC) % % F = ENFRAME(X,WINDOW) or ENFRAME(X,WINDOW,INC) multiplies % each frame by WINDOW(:) % % The second output argument, T, gives the time in samples at the centre % of each frame. T=i corresponds to the time of sample X(i). % % Example of frame-based processing: % INC=20 % set frame increment % NW=INC*2 % oversample by a factor of 2 (4 is also often used) % S=cos((0:NW*7)*6*pi/NW); % example input signal % W=sqrt(hamming(NW+1)); W(end)=[]; % sqrt hamming window of period NW % F=enframe(S,W,INC); % split into frames % ... process frames ... % X=overlapadd(F,W,INC); % reconstitute the time waveform (omit "X=" to plot waveform) % Copyright (C) Mike Brookes 1997 % Version: $Id: enframe.m,v 1.7 2009/11/01 21:08:21 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. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% nx=length(x(:)); nwin=length(win); if (nwin == 1) len = win; else len = nwin; end if (nargin < 3) inc = len; end nf = fix((nx-len+inc)/inc); f=zeros(nf,len); indf= inc*(0:(nf-1)).'; inds = (1:len); f(:) = x(indf(:,ones(1,len))+inds(ones(nf,1),:)); if (nwin > 1) w = win(:)'; f = f .* w(ones(nf,1),:); end if nargout>1 t=(1+len)/2+indf; end