Hello, I have a question about casting video to smart tvs. I run Linux Mint Cinnamon as one of my systems/desktop environments, and I realize there is GNOME Network Displays available to use for this. However, for me, I get two errors when trying to run it:
(gnome-network-displays:2430): Gnd-WARNING **: 11:37:13.971: Failed to create screencast session: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: No such interface “org.freedesktop.portal.ScreenCast”
After some searching through forums, I got the suggestion from an Ubuntu forum to fix the “org.freedesktop.portal.ScreenCast” error by installing the xdg-desktop-portal-dev package. I rebooted my computer after installing, then tried again. However I was met with the same errors as before plus a new one: ** (gst-plugin-scanner:2431): CRITICAL **: 11:37:13.773: _dma_fmt_to_dma_drm_fmts: assertion ‘fmt != GST_VIDEO_FORMAT_UNKNOWN’ failed
So at this point I am a bit stumped. Is this a problem with me not running an actual GNOME desktop environment (ie. this software only works specifically with GNOME desktop), or is there some other fix I can try?
Yeah I thinks it. GNOME Network Displays leans on the ScreenCast portal, which is provided by the GNOME portal backend, and Cinnamon doesn’t ship that.
You may need to try something like mkchromecast or gnomecast.
It’s okay, I can’t use these anyway. I had tried the GNOME Network Displays one because I do not have a Chromecast tv. The GNOME one apparently uses miracast as well (my non-Chrome tv showed up as an option to cast to, it’s just that the software does not actually work properly on Cinnamon apparently; on VLC or mkchromecast it does not show up at all).
This line that you included seems interesting to me. Avahi is a network implementation for multicast DNS and discovering other devices on a network specifically for sharing between devices, like a screencast.
This line seems to indicate that the avahi service can’t find the target you’re trying to screencast to. You’ll want to make sure that the avahi-daemon and avahi-utils packages are installed. I think they should be via GNOME, but you can double check with a sudo dpkg --list | grep avahi from the terminal.
If those are installed, then you’ll want to make sure the service is running (and starting at boot) with: sudo systemctl start avahi-daemon.service && sudo systemctl enable avahi-daemon.service.
Finally, assuming that you don’t see any errors in the service with sudo systemctl status avahi-daemon.service, then I’d ask if the device you’re trying to cast FROM and the device you’re trying to cast TO are on the same subnet. If they are not, then you may need to look at your router/firewall and enable multicast and/or avahi on that network device first so that your devices can discover each other.
The avahi packages are, most likely, still required even for Cinnamon’s DE. There would need to be some implementation for Avahi so that screencasting can work or be available, at least as far as I understand it.
The most important thing to check is the presence and status of the avahi-daemon.service. If your devices are all on the same subnet, then this may not be as relevant as what the other’s have mentioned, but still worth checking.
I’m not sure actually, I thought the Mint software manager was able to install both types of packages, but it’s been a while since I used it so I could be wrong.
The reason I asked is because the Flatpak might not use your system’s installed packages, but bundles its own dependencies. It would be great if you could verify whether it’s a system package or a Flatpak (perhaps the Mint software centre shows?).
Basically the default is system packages then if something is a flatpak it has a special label on it that says flatpak (flathub) on it. So unless something is marked that way then it seems that it is a .deb package.