xdg-desktop-portal-gtk

video feed goes where, use the same webcam for multiple applications, and have applications take a video feed, transform it, and plug it elsewhere. You can see where this is fitting with desktop sharing: one feed per window, one feed per screen, one feed for the whole desktop, plus variants. Want to overlay a webcam? No problem. Everything is backed by Gstreamer for realtime hardware-accelerated video encoding/decoding. And the icing on the cake: Flatpak spearheaded the development of "portals"[2]: cross-desktop interfaces for individual programs to ask the user when accessing restricted resources (like a microphone, or a folder on your computer). So, what's needed here is: * Finish up pipewire and have it shipped on most distributions (should be installed in fedora 31, optional for sound in 32, default for sound in 33) * Have compositors talk to pipewire [3] * Have browsers and other software talk to pipewire [4] * ??? * Profit Good progress is being made on these points, except maybe the last? I expect support to start working out-of-the-box in some distros/browser/compositor combinations in 2020. Actually, support seems further along than I thought it was. But it seems that wlroots-based compositor haven't yet decided to support the xdg screensharing portal, and rely instead on a custom wayland extension. I wouldn't be surprised if such a portal is implemented for those. The main issue here is everyone waiting on everyone else before enabling/implementing it. But it looks like we're 80% there, and it just needs to be enabled in some cases (and pipewire installed). Then it will trickle down to most distros and electrons apps. However, I don't think legacy X apps will be able to continue sharing the desktop (they can still be shared by wayland capture programs, or capture the desktop if they implement the new interface). I guess pipewire might be able to create a virtual webcam for these, though. Valve might be working on their own stack with their "Gamescope" wayland compositor[5], for their streaming solution. And in the end, this should work much better, with hardware encoding, actual security, zero copy, etc. Hopefully there won't be a "next big thing" that breaks everything in just a few years. [1] https://pipewire.org/ [1] https://wiki.archlinux.org/index.php/PipeWire [2] https://flatpak.github.io/xdg-desktop-portal/portal-docs.htm... [2] https://flatpak.github.io/xdg-desktop-portal/portal-docs.htm... [3] http://jgrulich.cz/2018/03/06/screen-sharing-in-plasma-wayla... [3] https://jgrulich.cz/2018/07/04/how-to-enable-and-use-screen-... [3] https://wiki.gnome.org/Projects/Mutter/RemoteDesktop [3] https://www.reddit.com/r/linux/comments/8le7rm/first_steps_f... [3] https://github.com/emersion/xdg-desktop-portal-wlr/issues/1 [4] https://bugzilla.mozilla.org/show_bug.cgi?id=1496359 (looks disabled by default at compile time) [4] https://bugs.chromium.org/p/chromium/issues/detail?id=682122 (pipewire disabled in chrome://flags until v81 due to waiting on https://github.com/flatpak/xdg-desktop-portal-gtk/issues/204 "dialog hell" it seems) [4] zoom currently uses a gnome-specific screenshot API as a workaround: https://www.reddit.com/r/swaywm/comments/dr8yld/zoom_screens... [5] https://www.gamingonlinux.com/articles/valve-give-a-little-m...