Here's an abstraction for computing a symmetric cross-covariance, this way. It outputs the cross-covariance, xcov(k)=sum(i=-32,...,31; s1(i+k)*s2(i)) It's still pretty ugly, and the details of the math confuse me a bit. I'm still working on the one-sided cross covariance function for delays, like from [0,63] instead of [-32,31]
and here's the same thing except it's a forward cross-covariance, called fxcov~.pd It's pretty much the same thing (up to a certain point), but as I've discovered, using xcov to calculate PSD and CSD for deconvolution can be tricky (even when it's a full rank system). There's a big diff between symmetric and forward cross-covariance in this respect. None of my reverberation measurement patches ever worked completely due to audio dropouts and badly formatted problems (I'm still working on it). The fxcov~ patch contains some math for your comparison.
Chuck