% ssBE676786 - estimate impulse response from chirp response measurement.

% Copyright 2007 Kind of Loud Technologies, LLC.  All rights reserved worldwide.
%
% Created: 10-Feb-7 at 14:20:21 by ssprobe for use with ssBE676786.wav.
% Version: v1.0.

%% initialization
cfile = 'ssBE676786.wav';	%% chirp file name, string
rfile = 'response.wav';	%% response file name, string

eta = 20;		%% chirp log2 length, exponent
asamp = 2^eta;	%% chirp length, samples

%% load chirp
[chirp fs] = wavread(cfile);

%% load chirp response
[response fsr] = wavread(rfile);
nc = size(response,2);

%% estimate impulse response
index = asamp + [1:asamp];
ir = real(ifft(fft(response(index,:))./fft(chirp(index,1))*ones(1,nc)));

%% display warning if sampling rates are incompatible
if (fs ~= fsr),
	disp(['SSFindIR: WARNING - incompatible chirp and response sampling rates.']);
end;