Deeplow - You asked for the commands used to install VLC, that I used. Here they are:

To install VLC in QubesOS v4.0.3

Using a chosen Template such as fedora-30: Open the official VLC download page in firefox (at time of writing it was https://www.videolan.org/vlc/ Click Download VLC (will probably say Fedora Linux) below the Download VLC button I used the first option - Fedora 22 and later (dnf)

Open a Terminal in the fedora-30 Template su - <enter> dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E%fedora).noarch.rpm
<enter> dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm <enter> dnf install vlc <enter>

In case vlc does not install (It didn't for me) I used this method from a 3 year old post found in a search: After the first three entries above, dnf -y update <enter> dnf install vlc <enter> if no success, there will be a message like:

> No package vlc available. Error: Unable to find a match.

If this is the case,

cd /etc/yum.repos.d/ <enter> sudo vim rpmfusion-free.repo <enter>

vim will open the rpmfusion-free.repo file. Vim commands if the reader has not used vim before are the letter i to enter edit mode, then edit as required and when done hit <escape> to exit the edit mode and then :wq! to save and exit. The line which will need editing will be near the beginning probably 7 lines down:

> enabled=0

Change the 0 to a 1 and then save and exit.

Now re-enter the lines dnf -y update and dnf install vlc VLC should now install in the Template. I needed to reboot the system for changes to take effect. But I'm new to Qubes and fedora. There might be a couple of shortcuts here, that someone more knowledgeable can suggest. Please feel free to edit and use as desired. cheers