Dawn@4: function standvar = mpeg7init(fs,hopsize,windowsize,window,FFTsize)
Dawn@4: 
Dawn@4: % This function creates a structure of the default values
Dawn@4: % to be used throughout the descriptors
Dawn@4: 
Dawn@4: % Written by Melanie Jackson
Dawn@4: 
Dawn@4: % Version 1 15th March 2001
Dawn@4: % Modified 30/04/2002 by Thorsten Kastner - changed standard hopsize to 30ms
Dawn@4: %                                         - set hopsize = windowsize (no overlap for ASF)
Dawn@4:   
Dawn@4: if nargin == 0
Dawn@4:     Error = 'need to specify the sampling frequency: standvar = mpeg7init(fs)'
Dawn@4:     standvar = [];
Dawn@4:     return 
Dawn@4: end
Dawn@4: 
Dawn@4: try	% variable defined
Dawn@4:     if isempty(hopsize)			% variable defined but no value
Dawn@4:       hopsize = [fs*30 1000]; % Changed hopsize: 30ms recommend
Dawn@4:     else
Dawn@4:         hopsize = [fs*hopsize(1) hopsize(2)];
Dawn@4:     end   
Dawn@4: catch
Dawn@4:     hopsize = [fs*30 1000] ;
Dawn@4: end
Dawn@4: [q, n, d] = h_fraction(hopsize(1),hopsize(2));
Dawn@4: % This next section of code is to ensure minimal stray from the sampling period
Dawn@4: % This is done by interleaving minor hopsize with major
Dawn@4: % e.g if  10 10 10 10 10 11 11 are the hops then the pattern should be
Dawn@4: % 10 10 10 11 10 10 11
Dawn@4: if n==0
Dawn@4:     hopsize = q;
Dawn@4: elseif d-n>=n
Dawn@4:     k = ceil((d-n)/n); % ratio of q to q+1 occurence
Dawn@4:     fr = floor((d-n)/(k)); % number of sub sequences required
Dawn@4:     frr = [q*ones(1,k) q+1]; % subsequence - length k+1
Dawn@4:     hopsize = reshape(frr'*ones(1,fr),1,(k+1)*fr); % append subsequences to each other
Dawn@4:     hopsize = [hopsize q*ones(1,d-n-k*fr) (q+1)*ones(1,n-fr)]; % attach extra values
Dawn@4: else  
Dawn@4:     k = ceil(n/(d-n));
Dawn@4:     fr = floor(n/k);
Dawn@4:     frr = [(q+1)*ones(1,k) q];
Dawn@4:     hopsize = reshape(frr'*ones(1,fr),1,(k+1)*fr);
Dawn@4:     hopsize = [hopsize (q+1)*ones(1,n-k*fr) q*ones(1,d-n-fr)];
Dawn@4: end
Dawn@4: 
Dawn@4: 
Dawn@4: try
Dawn@4:   if isempty(windowsize) 	% variable defined but no value
Dawn@4:       windowsize = ceil(fs*30/1000); % Changed:Windowsize fixed at 30ms
Dawn@4:     end
Dawn@4: catch
Dawn@4:   windowsize = ceil(fs*30/1000); % Changed: Windowsize fixed at 30ms
Dawn@4: end
Dawn@4: 
Dawn@4: try
Dawn@4:   if isempty(FFTsize)			% variable defined but no value
Dawn@4:     FFTsize = 2^nextpow2(windowsize);
Dawn@4:   end
Dawn@4: catch
Dawn@4:   FFTsize = 2^nextpow2(windowsize);
Dawn@4: end
Dawn@4: 
Dawn@4: try
Dawn@4:   if isempty(window)			% variable defined but no value
Dawn@4:     window = [hamming(windowsize)];
Dawn@4:   end
Dawn@4: catch
Dawn@4:   window = [hamming(windowsize)];
Dawn@4: end
Dawn@4: 
Dawn@4: standvar = struct('fs',fs,'hopsize',hopsize,'windowsize',windowsize,'window',window,'FFTsize',FFTsize);
Dawn@4: return