$ sudo apt-get update
$ sudo apt-get install gmerlin-encoders-ffmpeg 

gmerlin-encoders-ffmpeg is installed in your system.

Make ensure the gmerlin-encoders-ffmpeg package were installed using the commands given below,

$ sudo dpkg-query -l | grep gmerlin-encoders-ffmpeg *

You will get with gmerlin-encoders-ffmpeg package name, version, architecture and description in a table

gmerlin-encoders-ffmpeg package basic information: