This time I didn't use Celluloid, but my session is though destroyed at 4 pm as it began around 9 am
I am now blocked with a sound that is a loop and that is not controlled by the volume so I can only stop the volume on the device to stop hearing, but I cannot go on working with multimedia without restarting my session or worse
It happened as like I have allready described with Celluloid, a video is read in full screen, but this time it was with Xplayer and Smplayer (I had both) then the GUI doesn't respond ans so I must kill the process, i killed both but the sound is still there, and I cannot know if this sound was caused by the video players or by the internet browsers because I had also 3 internet browsers started (but RAM was at 50% level not more, with 15 GB)
So how to stop this sound without to restart the session ?
PS :
In fact I know where it comes from, a MPV window re-appeared, I don't know how because I had killed MPV process so how can it still be existing and it is not frozen, I can see this MPV Window only if I display the nemo window of the file that is read
it is really anything anything this exploitation system 
So I have a video being read by MPV and none related process
And if I put this video in full screen, nothing works to reduce it .... I can only switch with alt+tab
I don't know how to get out of this and if I close all, my afternoon is totally trashed