Grib2 geographic subdomain

[Pierre Cassar]

Hi all,
I would like to extract a geographic subdomain from a big GRIB2 file,
what should I use?

- The 'ggrib' utility can use only GRIB1 input files.

- The 'wgrib2' -lola option do not produce a grib output file (only
bin, text and spread mode).

- Converting the big grib2 file to grib1 with 'cnvgrib' and then using
'ggrib' is sloooow.

In fact I have i386 P4 machines running FreeBSD 6 and, as there's no
'cnvgrib' binary for FreeBSD, I must use a Linux binary in emulation
mode (kldload linux).

For example to convert a 260MB grib2 file to grib1 (cnvgrib -g21
file.grib2 file.grib1) my best FreeBSD machine tooks about *15
minutes*. That's very frustrating considering that I only need a
little geographical portion of the big file.

What to do?
Is there a faster way to convert from grib2 to grib1 in FreeBSD other
than 'cnvgrib' in emulation mode?
Is there a way to extract a "slice" from a grib2 file?

Thank you very much.
Pierre Cassar