Linux Mint (Cinnamon version included) probably already supports your multimedia shortcut keys! - Do you disagree? And are you using VLC? Then try to go to the advanced settings of VLC HotKeys and enable 'libNotify Notification Plugin'. - Did I just waste two days searching the nets for a solution to this, while, in the process, installing every single stale package that was at some time in the past used for support for multimedia keys? Well, yes, yes I did.