error while loading shared libraries

Just installed ffmpeg on Ubuntu 12 and tried running it only to see this error?

ffmpeg: error while loading shared libraries: libfdk-aac.so.0: cannot open shared object file: No such file or directory

ffmpeg is looking in the wrong spot for the library you installed. Try this bash command:

ldd `where ffmpeg`

And look for a line like this in the result to confirm the issue:

libfdk-aac.so.0 => not found

How to fix it

Using this additional command fixed my problem.

sudo ldconfig -v

This updates the lists of shared libraries cached in Ubuntu, and now ffmpeg can find that missing shared library.