starting ctc implementation

applications/SpatialAudio/ita_3da_ctcFilter_regularized.m

+function [ varargout ] = ita_3da_ctcFilter_regularized( varargin )
+%ITA_3DA_CTCFILTER_REGULARIZED Generates a set of CTC Filter for a
+%loudspeaker system with an arbitrary number of loudspeaker.
+
+%   The first input has to be a set of HRTF for each loudspeaker as
+%   multi-instance of itaAudio: [LS1_HRTF LS2_HRTF ... LSN_HRTF]
+%   or as one itaAudio containing:
+%   ch(1) = LS1 Left Ear
+%   ch(2) = LS1 Right Ear
+%   ch(3) = LS2 Left Ear
+%   ch(4) = LS2 Right Ear
+%   ch(5) = LS3 Left Ear
+%   ...
+%
+%   The calculation algorithm is a simple inversion. Pre- and
+%   Postprocessing options can be found below
+%
+%   For smoothing of HRTF or CTC filters use the functions provided by
+%   ita_3da_smoothing
+
+
+%% Options
+opts.beta            = 0.001; % regularization parameter
+opts.delay           = 400; % required delay to allow for causal filter
+opts.threshold       = 20; % threshold for ita_start_IR()
+opts.useStartIr      = false;
+opts.filterlength    = -1;
+
+%% Init
+hrtf=varargin(1);
+H=merge(hrtf);
+
+if ~isa(hrtf,'itaAudio')
+    error('First input (HRTF) has to be itaAudio')
+end
+
+if (H.nChannels<4)
+    error('At least two loudspeaker with two channels to each ear are needed!');
+end
+
+if ~strcmpi(H.signalType,'energy')
+    warning('HRTFs are not energy signals! Changing them to energy');
+    H.signalType='energy';
+end
+opts=ita_parse_arguments(opts,varargin(2:end));
+
+%% Preprocessing
+if (opts.filterlength==-1)
+    H = ita_extend_dat(H,max(2*H.nSamples,2^12),'forceSamples');
+else
+    H = ita_extend_dat(H,opts.filterLength,'forceSamples');
+end
+
+if opts.
+
+
+%% Calculation
+N = H.nSamples;
+[hm,hn] = size(H);
+f = H.nBins;
+hfq = H.freqData;
+c = zeros(hn,hm,f);
+CTC = itaAudio(hn,hm);
+for fdx = 1:f
+    hh = reshape(hfq(fdx,:),hm,hn);
+    c(:,:,fdx) = hh'/(hh*hh' + opts.beta*eye(hm));
+end
+aux = H(1,1);
+for idx = 1:hn
+    for jdx = 1:hm
+        aux.freqData = squeeze(c(idx,jdx,:));
+        CTC(idx,jdx) = aux;
+    end
+end
+
+
+
+%% Postprocessing
+
+
+
+
+end
+