Take a look here: "Missing codecs" after installing ffmpeg with Linux - #4 by Nickpi
You will have to this as root (or with sudo in this case) from a terminal:
- Mount the ROCK data folder to
/mnt/on your computer
sudo mount -t cifs //rock/Data -o vers=1.0 /mnt/ - Maybe you will have to change the directory where your extracted file is first, e.g.
cd /home/user/Downloads) - Copy your ffmpeg file to the mounted ROCK folder
sudo cp ffmpeg /mnt/Codecs
After that a reboot can not hurt.
Edit
Forgot to mention:
I wrote a bit about my ROCK project (to remind myself) on github. Maybe there is one or the other interesting information here.