All,
Adding a quick comment to support the position that Ed and John are
taking: given the restrictions on szip support I feel pretty confident
that the CF group would elect to forbid its use in CF-compliant files.
A key reason for enthusiasm about netCDF-CF is the degree to which it
promotes interoperability. Files that can be read only by a restricted
(licensed?!) set of software at certain sites would not meet this test.
Quite the opposite; we'd be introducing a serious stumbling block to
interoperability. The need for client writers to support multiple
client software builds would be a HUGE downside to offset the potential
advantages of szip.
- Steve
=============================
John Caron wrote:
I think its a mistake to promote the use of a proprietary compression
scheme, unless it was much better, which i doubt it is. If the szip
patent holders would like to release their IP claims then that would
be another matter.
I also think its fatal that theres no java implementation, and theres
doubt whether one could legally be written. We would then be in the
position of writing netcdf-4 files (by the C netcdf library) that cant
be read by the java netcdf library.
OTOH, trying to read existing szipped data is a good thing if
possible, since there may be Important Stuff in There, that wants to
be set free.
Ted Mansell wrote:
Ed, et al.,
Szip Cons:
* No existing Java version.
* License restrictions for commercial writers of data.
* Some (or most) netCDF-4 installations will not be able to read
szipped
files without rebuilding netCDF.
* Will not (and should not) be used by CMIP5 effort and (probably)
other
important archives.
* Due to licensing szip will not be available in stock Fedora
distribution. Fedora is a very popular Linux distribution, and at
least
some other free software distributions will probably feel the same
about szip licensing problems.
All of these apply equally well to hdf5, so why is it a big deal?
szip is not a default option for hdf5, so probably most folks don't
use it, anyway. I think if you already put it in, it might as well
stay in for those who want to use it and don't need to worry about
compatibility. (I'm sure plenty of commercial software doesn't even
read netcdf4 yet, either.)
As for Fedora users, they should be able to install stuff that they
want. I'm not complaining that OS X doesn't have szip in the stock
install.... get the tar file and go.
If licensing is really an issue, it could be a separate config option
to enable writing of szip (e.g., --enable-write-szip), and let
--with-szip just enable reading.
Is it just a matter of time before the Java version catches up? Not
that I use it....
Best,
-- Ted
_______________________________________________
netcdfgroup mailing list
netcdfgroup@xxxxxxxxxxxxxxxx
For list information or to unsubscribe, visit:
http://www.unidata.ucar.edu/mailing_lists/
_______________________________________________
netcdfgroup mailing list
netcdfgroup@xxxxxxxxxxxxxxxx
For list information or to unsubscribe, visit:
http://www.unidata.ucar.edu/mailing_lists/
