No gnome-mpv is not recommended and does not “work” with respect to hardware acceleration.
For example when playing a 4K video I get:
- gnome-mpv 300% CPU
- mpv 6% CPU
So gnome-mpv would need some work. The problems appear to be:
- Hardware-acceleration is not enabled by default.
- If you enable hardware-acceleration then the window decoration and buttons flicker badly, but also CPU usage is still high.
- gnome-mpv uses the GtkGLArea widget. In theory this is the right thing to do, however in practice app developers probably are not aware that GtkGLArea is very inefficient: https://bugzilla.gnome.org/show_bug.cgi?id=787704 Sadly app developers also have few other options for integrating a hardware surface into a GTK app. And the only alternative I can think of is also broken: https://bugzilla.gnome.org/show_bug.cgi?id=787001
So TL;DR - use only mpv, not gnome-mpv.