I am runnning a Debian Stretch distribution with Cinnamon graphical interface.
I use this command to turn off the display
xset dpms force off
It is useful to me when I want to sleep and just launch a video without being perturbed by the light of my screen. Note that if the mouse pointer is active (moves), then the display is turn on.
If the video is launched by VLC or Totem Movie Player, all is working fine.
If the video is launched by mplayer, display is turn off for 12s and then the video appears which is not what I expect...
I don't know why does the command "xset dpms force off" stop with the mplayer's app.