Octave Forge ltfat

function f=comp_iwpfbt(c,wtNodes,pOutIdxs,chOutIdxs,Ls,ext,interscaling)
%COMP_IWFBT Compute Inverse Wavelet Packet Filter-Bank Tree
%   Usage:  f=comp_iwpfbt(c,wtNodes,pOutIdxs,chOutIdxs,Ls,ext)
%
%   Input parameters:
%         c          : Coefficients stored in cell array.
%         wtNodes    : Filterbank tree nodes (elementary filterbans) in
%                      reverse BF order. Cell array of structures of length *nodeNo*.
%         pOutIdxs   : Idx of each node's parent. Array of length *nodeNo*.
%         chOutIdxs  : Idxs of each node children. Cell array of vectors of
%                      length *nodeNo*.
%         ext        : Type of the forward transform boundary handling.
%
%   Output parameters:
%         f          : Reconstructed data in L*W array.
%

% Do non-expansve transform if ext=='per'
doPer = strcmp(ext,'per');

interscalingfac = 1;
if strcmp('intscale',interscaling)
    interscalingfac = 1/2;
elseif strcmp('intsqrt',interscaling)
    interscalingfac = 1/sqrt(2);
end


% For each node in tree in the BF order...
 for jj=1:length(wtNodes)
    % Node filters to a cell array
    %gCell = cellfun(@(gEl)conj(flipud(gEl.h(:))),wtNodes{jj}.g(:),'UniformOutput',0);
    gCell = cellfun(@(gEl)gEl.h(:),wtNodes{jj}.g(:),'UniformOutput',0);
    % Node filters subs. factors
    a = wtNodes{jj}.a;
    % Node filters initial skips
    if(doPer)
       %offset = cellfun(@(gEl) 1-numel(gEl.h)-gEl.offset,wtNodes{jj}.g);
       offset = cellfun(@(gEl) gEl.offset,wtNodes{jj}.g);
    else
       offset = -(a-1);
    end
    
    if(pOutIdxs(jj))
       % Run filterbank and add to the existing subband.
       ctmp = comp_ifilterbank_td(c(chOutIdxs{jj}),gCell,a,size(c{pOutIdxs(jj)},1),offset,ext);
       c{pOutIdxs(jj)} = c{pOutIdxs(jj)}+ctmp;
    
       c{pOutIdxs(jj)} = interscalingfac*c{pOutIdxs(jj)};
       
    else
       % We are at the root.
       f = comp_ifilterbank_td(c(chOutIdxs{jj}),gCell,a,Ls,offset,ext);
    end
 end