Support installing without `ffmpeg` and `ffprobe` binary

[anwarulislam]

Currently, the installation process requires the presence of ffmpeg and ffprobe binaries. This dependency can be a barrier for users who may not need these tools (already installed in the device/system) or prefer a lighter installation. We propose to modify the installation process to allow installation without these binaries.

[0x464e]

Hi, that sounds sensible and is a good suggestion. I will look into this when I have time for my hobby projects again (sorry, it will be a while).