1function [Lc,L]=fwtclength(Ls,w,J,varargin)
2%-*- texinfo -*-
3%@deftypefn {Function} fwtclength
4%@verbatim
5%FWTCLENGTH FWT subbands lengths from a signal length
6%   Usage: Lc=fwtclength(Ls,w,J);
7%          [Lc,L]=fwtclength(...);
8%
9%   Lc=FWTCLENGTH(Ls,w,J) returns the lengths of the wavelet coefficient
10%   subbands for a signal of length Ls. Please see the help on FWT for
11%   an explanation of the parameters w and J.
12%
13%   [Lc,L]=FWTCLENGTH(...) additianally the function returns the next
14%   legal length of the input signal for the given extension type.
15%
16%   The function support the same boundary-handling flags as the FWT
17%   does.
18%
19%@end verbatim
20%@strong{Url}: @url{http://ltfat.github.io/doc/wavelets/fwtclength.html}
21%@seealso{fwt, fwtlength}
22%@end deftypefn
23
24% Copyright (C) 2005-2016 Peter L. Soendergaard <peter@sonderport.dk>.
25% This file is part of LTFAT version 2.3.1
26%
27% This program is free software: you can redistribute it and/or modify
28% it under the terms of the GNU General Public License as published by
29% the Free Software Foundation, either version 3 of the License, or
30% (at your option) any later version.
31%
32% This program is distributed in the hope that it will be useful,
33% but WITHOUT ANY WARRANTY; without even the implied warranty of
34% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
35% GNU General Public License for more details.
36%
37% You should have received a copy of the GNU General Public License
38% along with this program.  If not, see <http://www.gnu.org/licenses/>.
39
40% AUTHOR: Zdenek Prusa
41
42complainif_notposint(Ls,'Ls','FWTCLENGTH');
43complainif_notposint(J,'J','FWTCLENGTH');
44
45w = fwtinit(w);
46
47definput.import = {'fwtext'};
48[flags,kv]=ltfatarghelper({},definput,varargin);
49
50% Get the next legal length
51L = fwtlength(Ls,w,J,flags.ext);
52
53filtNo = length(w.g);
54subbNo = (filtNo-1)*J+1;
55Lc = zeros(subbNo,1);
56runPtr = 0;
57levelLen = L;
58if flags.do_per
59  % Non-expansive case
60  for jj=1:J
61     for ff=filtNo:-1:2
62        Lc(end-runPtr) = ceil(levelLen/w.a(ff));
63        runPtr = runPtr + 1;
64     end
65     levelLen = ceil(levelLen/w.a(1));
66  end
67% elseif flags.do_valid
68%   % Valid coef. case
69%   filts = w.g;
70%   for jj=1:J
71%      for ff=filtNo:-1:2
72%         Lc(end-runPtr) = floor((levelLen-(length(filts{ff}.h)-1))/w.a(ff));
73%         runPtr = runPtr + 1;
74%      end
75%      levelLen = floor((levelLen-(length(filts{1}.h)-1))/w.a(1));
76%   end
77else
78  % Expansive case
79  filts = w.g;
80  for jj=1:J
81    for ff=filtNo:-1:2
82       skip = w.a(ff) - 1;
83       Lc(end-runPtr) = ceil((levelLen+(length(filts{ff}.h)-1)-skip)/w.a(ff));
84       runPtr = runPtr + 1;
85    end
86    skip = w.a(1) - 1;
87    levelLen = ceil((levelLen+(length(filts{1}.h)-1)-skip)/w.a(1));
88 end
89end
90Lc(1)=levelLen;
91
92