In article ,
Jim Lesurf wrote:
Two follow-on issues I want to raise:

First...

I've been using the version of ffmpeg I built following the recipy given
here a while ago. This works fine on my laptop and main machine. I've made
a number of useful (and enjoyable!) R3 recordings using them.

But it doesn't work on another machine.

The machine where it fails to run is one which I installed xfce Mint 18.1
onto a few days ago. (32 bit version as it has a 32 bit cpu)

On that, when I try to run the ffmpeg executable I get

Error while loading shared libraries: libgnutls.so.26: cannot open shared
object: no such file or directory.

I assume this means it can't find libgnutls.so.26 ?

Seems so. You can check the library usage of any executable with ldd, like so:

$ ldd /path/to/ffmpeg

Any libs which can't be found will be named as such. Then apt-file can
be used to find out the package which provides that file:

$ apt-get install apt-file
$ apt-file update
$ apt-file search libgnutls.so.26
libgnutls26: /usr/lib/i386-linux-gnu/libgnutls.so.26
libgnutls26: /usr/lib/i386-linux-gnu/libgnutls.so.26.22.4
libgnutls26-dbg: /usr/lib/debug/usr/lib/i386-linux-gnu/libgnutls.so.26.22.4

If you have this installed already, it could be a multi-arch issue, if
the binary was built on a non-multiarch distro for instance. Try using
LD_LIBRARY_PATH to help the loader, sonething like:

$ LD_LIBRARY_PATH=/usr/lib/i386-linux-gnu ffmpeg

Although to be honest I'd have expected Mint's libc6 to have
the multi-arch directories already named in its search paths via
/etc/ld.so.conf.d/i386-linux-gnu.conf .

I am trying to remember other causes of library problems but will have
to think. Hope this might help anyway,

Nick
--
"The Internet, a sort of ersatz counterfeit of real life"
-- Janet Street-Porter, BBC2, 19th March 1996