gusucode.com > 《MATLAB图像与视频处理实用案例详解》代码 > 《MATLAB图像与视频处理实用案例详解》代码/第 19 章 基于语音识别的信号灯图像模拟控制技术/voicebox/fram2wav.m
function [w,s]=fram2wav(x,tt,mode)
%FRAM2WAV converts frame values to a continuous waveform [W]=(X,TT,MODE)
% Inputs:
% x(nf,p) is the input signal: one row per frame
% tt(nf,3) specifies the frames. Each row has the form [start_sample end_sample flag]
% where flag = 1 for the start of a new spurt.
% If tt(:,3) is omitted, a new spurt will be started whenever there is a gap
% of more than one between the end of one frame and the beginning or the next.
% A new spurt is automatically started if x() = NaN.
% mode consists of one or more of the following letters:
% z for zero-order hold interpolation (i.e. constant within each frame)
% l for linear interpolation within each spurt [default]
%
% Outputs:
% w(n,p) contains the interpolated waveforms. Their length is n = tt(nf,2)
% s(ns,2) gives the starting and ending sample numbers of each spurt (excluding NaN spurts)
%
% This routine converts frame-based values to continuous waveforms by performing
% a chosen method of interpolation. Interpolation is restarted at the beginning of each spurt.
% Bugs/Suggestions
% (1) Additional mode option for cubic interpolation
% (2) Additional mode option for interpolation in log domain
% (3) Additional mode option for x values being
% frame averages rather than mid-frame values.
% Copyright (C) Mike Brookes 1997
% Version: $Id: fram2wav.m,v 1.4 2007/05/04 07:01:38 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<3
mode='l';
end
[nf,m]=size(x);
n=round(tt(end,2));
w=repmat(NaN,n,m);
nt=size(tt,2);
ix1=ceil(tt(:,1)); % start of frame sample
ix2=floor(tt(:,2)); % end of frame sample
% determine the start and end of spurts
if nt>2
ty=tt(:,3)>0; % frame type set by user
else
ty=zeros(nf,1);
ty(2:end)=ix1(2:end)>ix2(1:end-1)+1; % new spurt whenever a gap
end
ty(1)=1; % first frame always starts a spurt
ty(isnan(x))=1; % NaN always ends previous spurt
ty(1+find(isnan(x(1:end-1))))=1; % NaN always forces a new spurt
ty=double(ty);
ty(1:end-1)=ty(1:end-1)+2*ty(2:end);
ty(end)=ty(end)+2; % last frame always ends a spurtw=repmat(NaN,n,m); % initialize output to all NaN
nx=ix2-ix1+1;
if any(mode=='z') % zero-order hold
for i=1:nf
if nx(i)
w(ix1(i):ix2(i),:)=repmat(x(i,:),nx(i),1);
end
end
else % linear interpolation is the default
ttm=(tt(:,1)+tt(:,2))/2; % mid point of frame
ixm=floor(ttm); % end of first half of frame
for i=1:nf
if i==176
i
end
if nx(i)
tyi=ty(i);
if tyi==3 % use a zero order hold
w(ix1(i):ix2(i),:)=repmat(x(i,:),nx(i),1);
else
nxm=ixm(i)-ix1(i)+1;
if nxm
if tyi==1
grad=(x(i+1,:)-x(i,:))/(ttm(i+1)-ttm(i));
else
grad=(x(i,:)-x(i-1,:))/(ttm(i)-ttm(i-1));
end
w(ix1(i):ixm(i),:)=repmat(x(i,:),nxm,1)+((ix1(i):ixm(i))'-ttm(i))*grad;
end
if nx(i)>nxm
if tyi==2
grad=(x(i,:)-x(i-1,:))/(ttm(i)-ttm(i-1));
else
grad=(x(i+1,:)-x(i,:))/(ttm(i+1)-ttm(i));
end
w(ixm(i)+1:ix2(i),:)=repmat(x(i,:),ix2(i)-ixm(i),1)+((ixm(i)+1:ix2(i))'-ttm(i))*grad;
end
end
end
end
end
% now sort out the start and end spurt positions
ty(isnan(x))=0; % Don't count NaN spurts
s=repmat(ix1(bitand(ty,1)>0),1,2);
s(:,2)=ix2(bitand(ty,2)>0);
if ~nargout
tw=(1:n)';
for i=size(s,1):-1:2
j=s(i,1); % start of new spurt
tw=[tw(1:j-1); tw(j); tw(j:end)];
w=[w(1:j-1); NaN; w(j:end)]; % insert a NaN to force a plotting break
end
plot(tt(:,1:2)',repmat(x(:)',2,1),'r-+',tw,w,'b-');
end