% ssBCE479C5 - estimate impulse response from chirp response measurement.

% Copyright 2004 Kind of Loud Technologies, LLC.  All rights reserved worldwide.
%
% Created: 27-Apr-6 at 02:30:37 by ssprobe for use with ssBCE479C5.wav.
% Version: v1.0.

%% initialization
cfile = 'ssBCE479C5.wav';	%% chirp file name, string
rfile = 'response.wav';	%% response file name, string

nr = 2;		%% chirp repetitions, chirps
eta = 18;		%% chirp log2 length, exponent
asamp = 2^eta;	%% chirp length, samples

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

%% load chirp response
[response fsr] = wavread(rfile);

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

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