Comment 7 for bug 589722

There's a module that takes care of this but requires recompiling vlc I guess:
https://github.com/jjk-jacky/abs/blob/726bba27c787339f331ae92380119281f20f4ff6/vlc-jjk/0001-Add-dpms-module-to-switch-it-off-while-playing.patch
(requires disabling screensaver and power management in Preferences, because it handles them instead)

But if you want another variant(if the above isn't what you want for some reason), then this is what I am using now (for vlc-git): https://github.com/emanueLczirai/coostomhuston/blob/c3b3108cd1fba34ac8e0056f38eb8024261439fb/system/lenovo%20z575/OS/manjaro/filesystem%20now/home/emacs/build/vlc-git/0001_allow_screensaver_and_power_management_while_video_is_paused.patch
(this variant doesn't require you changing any vlc settings; although it's a hacky way of implementing this feature AND it "forces" vlc to use xdg-screensaver to inhibit screensaver and powermanagement from triggering during playback; the other way vlc would use is dbus to inhibit...)

Both work for me btw; Result: vlc doesn't let screensaver, screen blanking, power management trigger while video(or audio) is playing, but allows them to kick in while the video is paused.

Hope this helps someone somehow.

Cheers,
EmanueL

PS: don't kill me? :)

PS2: relevant thread of people asking for this feature: https://forum.videolan.org/viewtopic.php?t=100211