function L=wfbtlength(Ls,wt,varargin);
%WFBTLENGTH WFBT length from signal
% Usage: L=wfbtlength(Ls,wt);
%
% WFBTLENGTH(Ls,wt) returns the length of a Wavelet system that is long
% enough to expand a signal of length Ls. Please see the help on
% WFBT for an explanation of the parameter wt.
%
% If the returned length is longer than the signal length, the signal
% will be zero-padded by WFBT to length L.
%
% In addition, the function accepts flags defining boundary extension
% technique as in WFBT. The returned length can be longer than the
% signal length only in case of 'per' (periodic extension).
%
% See also: wfbt, fwt
%
% Url: http://ltfat.github.io/doc/wavelets/wfbtlength.html
% Copyright (C) 2005-2023 Peter L. Soendergaard <peter@sonderport.dk> and others.
% This file is part of LTFAT version 2.6.0
%
% 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 3 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 should have received a copy of the GNU General Public License
% along with this program. If not, see <http://www.gnu.org/licenses/>.
% AUTHOR: Zdenek Prusa
complainif_notposint(Ls,'Ls','WFBTLENGTH');
definput.import = {'fwt'};
[flags,kv]=ltfatarghelper({},definput,varargin);
% Initialize the wavelet filters structure
if ~isstruct(wt)
wt = wfbtinit(wt);
end
if(flags.do_per)
a = treeSub(wt);
L = filterbanklength(Ls,a);
else
L = Ls;
end