After installing FFMpeg , when you execute the command : ffmpeg or ffmpeg -v, you may receive an error.

ffmpeg: error while loading shared libraries: libavformat.so.50:

Solution :

Execute the following command :

export LD_LIBRARY_PATH=/usr/local/lib:LD_LIBRARY_PATH

But this value will be cleared once you log off that session.

So it is recommended to save this value in bashrc.

vi .bashrc

LD_LIBRARY_PATH=/usr/local/lib