Filter using SOS
Filter using SOS

I think that Liquid can't filter small nums like those
for 63 Hz and 3000 Hz sample rate due to precision.

I tried using second order samples and although the
function iirdes_isstable() is false, the filtered
results are relatively close to those of MATLAB and no
longer look unstable.

In addition, the resampled, unfiltered data points from
ffmpeg do not exactly match the MATLAB output, but they
are close.

Signed-off-by: Kim Jones <160cf344c1362ca60c9492925665d2bb268437e5@edu.salford.ac.uk>

kimmariejon3s/rt-blind-estimator