diff userProgramsTim/enframe.m @ 38:c2204b18f4a2 tip

End nov big change

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/userProgramsTim/enframe.m	Mon Nov 28 13:34:28 2011 +0000
@@ -0,0 +1,74 @@
+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
+
+