MFCC.zip_MATLAB MFCC_MFCC_声音 特征提取_声音特征

function [f,t,w]=enframe(x,win,inc,m) %ENFRAME split signal up into (overlapping) frames: one per row. [F,T]=(X,WIN,INC) % % Usage: (1) f=enframe(x,n) % split into frames of length n % % (2) f=enframe(x,hamming(n,'periodic'),n/4) % use a 75% overlapped Hamming window of length n % % Inputs: x input signal % win window or window length in samples % inc frame increment in samples % m mode input: % 'z' zero pad to fill up final frame % 'r' reflect last few samples for final frame % 'A' calculate window times as the centre of mass % 'E' calculate window times as the centre of energy % % Outputs: f enframed data - one frame per row % t fractional time in samples at the centre of each frame % w window function used % % By default, the number of frames will be rounded down to the nearest % integer and the last few samples of x() will be ignored unless its length % is lw more than a multiple of inc. If the 'z' or 'r' options are given, % the number of frame will instead be rounded up and no samples will be ignored. % % Example of frame-based processing: % INC=20 % set frame increment in samples % 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),'periodic')); % 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) % Bugs/Suggestions: % (1) Possible additional mode options: % 'u' modify window for first and last few frames to ensure WOLA % 'a' normalize window to give a mean of unity after overlaps % 'e' normalize window to give an energy of unity after overlaps % 'wm' use Hamming window % 'wn' use Hanning window % 'x' include all frames that include any of the x samples % Copyright (C) Mike Brookes 1997-2012 % Version: $Id: enframe.m 1713 2012-03-30 21:27:46Z dmb $ % % 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(:)); if nargin<2 || isempty(win) win=nx; end if nargin<4 || isempty(m) m=''; end nwin=length(win); if nwin == 1 lw = win; w = ones(1,lw); else lw = nwin; w = win(:)'; end if (nargin < 3) || isempty(inc) inc = lw; end nli=nx-lw+inc; nf = fix((nli)/inc); na=nli-inc*nf; f=zeros(nf,lw); indf= inc*(0:(nf-1)).'; inds = (1:lw); f(:) = x(indf(:,ones(1,lw))+inds(ones(nf,1),:)); if nargin>3 && (any(m=='z') || any(m=='r')) && na>0 if any(m=='r') ix=1+mod(nx-na:nx-na+lw-1,2*nx); f(nf+1,:)=x(ix+(ix>nx).*(2*nx+1-2*ix)); else f(nf+1,1:na)=x(1+nx-na:nx); end nf=size(f,1); end if (nwin > 1) % if we have a non-unity window f = f .* w(ones(nf,1),:); end if nargout>1 if any(m=='E') t0=sum((1:lw).*w.^2)/sum(w.^2); elseif any(m=='E') t0=sum((1:lw).*w)/sum(w); else t0=(1+lw)/2; end t=t0+inc*(0:(nf-1)).'; end