I know it’s been a while but I tried the flatpak version of mpv and it’s not working. If I open the flatpak version without any music it opens but it becomes unresponsive as soon as I try to load any music. I also have no idea how to diagnose this issue as running the flatpak version in the terminal gives no error messages.
The version that comes with Linux Mint works perfectly fine, so I don’t need the flatpak version, I’m just curious as to why the flatpak version doesn’t work.
I think I also had this issue using Cinnamon once, but then I just used VLC instead. Never bothered to look into why. Worked fine in GNOME for me though.
I found a thread with a similar issue: https://forums.opensuse.org/t/flatpak-mpv-broken-since-20240306-snapshot/172981
There it seems the issue was audio. Try running the flatpak version with
flatpak run io.mpv.Mpv --ao=pulse path-to-your-media-file
If the issue is with the DE, I’m actually using the Xfce edition of Linux Mint. I would just use VLC but it gives me performance issues because I don’t have the best hardware and mpv seems to work much more efficiently. But yeah, changing the audio output fixed this issue, I’m guessing the flatpak version of mpv defaults to pipewire. I was curious and I did test pipewire with both versions and I got the same results that they did.