libaec is a free implementation of the Golomb-Rice compression method as
described in the Recommendation for Space Data System Standard 121.0-B-2.
Another implementation of this standard is szip which is already supported
by HDF5 and thus netCDF4.
The main reason to use this compression method is that is is very fast for
both compression and decompression and yields a good compression ratio for
typical low entropy data.
libaec has a szip API compatibility layer and can be used as a drop-in
replacement for szip. It also has its own API which allows you to use more
recent additions to the standard and the coding of data streams among other
things.
The code is available under a BSD license. As you may know, NASA holds a
patent on parts of the method. Our understanding from communication with
NASA's Chief Patent Counsel is that they have effectively abandoned this
patent and anyone is free to make 'use of its teachings and claims'. See
doc/license.txt for further information on this matter.
All szip related tests in HDF5 pass with libaec and several people on
campus here tested the code with HDF5 and GRIB. Still, this being the first
release we would be very interested to get feedback on possible bugs and
incompatibilities.
You can download the code from:
https://www.dkrz.de/redmine/projects/aec/wiki/Downloads
Cheers,
Mathis
--
Mathis Rosenhauer
German Climate Computing Centre
