Inhibit screensaver: mpv flatpak on GNOME wayland (workaround)

inhibit-screensaver.lua

-- ~/.var/app/io.mpv.Mpv/config/mpv/scripts/inhibit-screensaver.lua
--
-- Workaround for inhibiting screensaver for io.mpv.Mpv flatpak (if not paused)
-- Issue: [vo/gpu/wayland] GNOME's wayland compositor lacks support for the idle inhibit protocol. This means the screen can blank during playback.
-- Until this is merged: https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/111
-- Non-flatpak version: https://gist.github.com/crazygolem/a7d3a2d3c0cee5d072c0cbbbdee69286
--
-- NOTE: if mpv does not exit cleanly (e.g. with SIGKILL), an orphan process will keep inhibiting the screensaver 
--
-- Arch: x86_64
-- REQUIRED: flatpak override --user --talk-name=org.gnome.SessionManager io.mpv.Mpv
require 'mp.msg'

inhibits = {
  video={reason="Playing video", inhibit="suspend:idle", proc=nil},
  audio={reason="Playing audio", inhibit="suspend", proc=nil}
}
props = {pause=0, stop_screensaver=0, window_minimized=0, mute=0}

function inhibit(kind)
  inhibits[kind].proc = mp.command_native_async({
    name = "subprocess",
    playback_only = false,
    capture_stdout = true,
    args = { "/run/host/lib64/ld-linux-x86-64.so.2",
    "--library-path", "/run/host/lib64",
    "/run/host/usr/bin/gnome-session-inhibit", 
    "--app-id", "io.mpv.Mpv",
    "--reason", inhibits[kind].reason,
    "--inhibit", inhibits[kind].inhibit,
    "--inhibit-only"
  }}, function(success, result, error)
    mp.msg.verbose('gnome-session-inhibit stopped for ' .. kind)
    if result ~= nil and #result.stdout ~= 0 then
      mp.msg.debug(result.stdout)
    end
    inhibits[kind].proc = nil
  end)
end

function maybe_toggle_inhibit(kind, paused, should_inhibit)
  local proc = inhibits[kind].proc
  if paused or not should_inhibit then
    -- uninhibit screensaver
    if proc ~= nil then
      mp.msg.verbose('stop gnome-session-inhibit for ' .. kind)
      mp.abort_async_command(proc)
    end
  elseif should_inhibit then
    -- inhibit screensaver
    if proc == nil then
      mp.msg.verbose('start gnome-session-inhibit for ' .. kind)
      inhibit(kind)
    end
  end
end

function update(name, value)
  props[name:gsub("-", "_")] = value
  maybe_toggle_inhibit("video",
    props.pause,
    props.stop_screensaver and not props.window_minimized)
  maybe_toggle_inhibit("audio",
    props.pause,
    props.stop_screensaver and not props.mute)
end

for prop,_ in pairs(props) do
  mpv_prop = prop:gsub("_", "-")
  props[prop] = mp.get_property_bool(mpv_prop)
  mp.observe_property(mpv_prop, "bool", update) 
end

inhibit-with-heartbeat.lua

-- ~/.var/app/io.mpv.Mpv/config/mpv/scripts/inhibit-screensaver.lua
--
-- [Heartbeat] version: if you are worried about mpv not exiting normally (orphan process) 
--
-- Workaround for inhibiting screensaver for io.mpv.Mpv flatpak (if not paused)
-- 
-- Arch: x86_64
-- REQUIRED: flatpak override --user --talk-name=org.gnome.SessionManager io.mpv.Mpv
require 'mp.msg'

inhibits = {
  video={reason="Playing video", inhibit="suspend:idle", do_inhibit=false, dead=true},
  audio={reason="Playing audio", inhibit="suspend", do_inhibit=false, dead=true}
}
props = {pause=0, stop_screensaver=0, window_minimized=0, mute=0}

function inhibit(kind)
  local active = inhibits[kind].do_inhibit
  if active then
    mp.command_native({ name = "subprocess",
      playback_only = false,
      detach = true,
      args = { "/run/host/lib64/ld-linux-x86-64.so.2",
      "--library-path", "/run/host/lib64",
      "/run/host/usr/bin/gnome-session-inhibit", 
      "--app-id", "io.mpv.Mpv",
      "--reason", inhibits[kind].reason,
      "--inhibit", inhibits[kind].inhibit,
      "sleep", "1"
    }})
  end
  inhibits[kind].dead = not active
end

function heartbeat()
  inhibit("video")
  inhibit("audio")
end

function maybe_toggle_inhibit(kind, paused, should_inhibit)
  active = inhibits[kind].do_inhibit
  if paused or not should_inhibit then
    -- uninhibit screensaver
    if active then
      mp.msg.verbose('stop gnome-session-inhibit for ' .. kind)
      inhibits[kind].do_inhibit = false
    end
  elseif should_inhibit then
    -- inhibit screensaver
    if not active then
      mp.msg.verbose('start gnome-session-inhibit for ' .. kind)
      inhibits[kind].do_inhibit = true
      if inhibits[kind].dead then
        heartbeat()
      end
    end
  end
end

function update(name, value)
  props[name:gsub("-", "_")] = value
  maybe_toggle_inhibit("video",
    props.pause,
    props.stop_screensaver and not props.window_minimized)
  maybe_toggle_inhibit("audio",
    props.pause,
    props.stop_screensaver and not props.mute)
end

for prop,_ in pairs(props) do
  mpv_prop = prop:gsub("_", "-")
  props[prop] = mp.get_property_bool(mpv_prop)
  mp.observe_property(mpv_prop, "bool", update) 
end

-- lowest screensaver setting 60 sec => heatbeat 59 seconds is enough
mp.add_periodic_timer(59, heartbeat)

Allow io.mpv.Mpv to talk to the session-manager dbus-destination:

flatpak override --user --talk-name=org.gnome.SessionManager io.mpv.Mpv

Then install this script with lazy-inhibit:

curl -o ~/.var/app/io.mpv.Mpv/config/mpv/scripts/inhibit-screensaver.lua https://gist.githubusercontent.com/Deminder/6839fad736865cb3acabab409f9b09a1/raw/5c7d606733074aed8de3e542743229852fc34337/inhibit-screensaver.lua

or with heartbeat-inhibit:

curl -o ~/.var/app/io.mpv.Mpv/config/mpv/scripts/inhibit-screensaver.lua https://gist.githubusercontent.com/Deminder/6839fad736865cb3acabab409f9b09a1/raw/5c7d606733074aed8de3e542743229852fc34337/inhibit-with-heartbeat.lua