First thing that comes to mind is that your screen saver isn't hindered
and triggers because no user action has taken place.

For mplayer, you can create a .mplayer/config file and insert the
following line in it :

> heartbeat-cmd="xscreensaver-command -deactivate >&- 2>&- &"

Search google for other software.

On 30/08/20 06:19, Frank Streitz wrote:
> sorry for my bad English but I try to describe my problem so good as I
> can. If I look a video or live stream the screen is after 10 minutes
> dark. Only chromecast is able to hold the screen open. Firefox or VLC
> media player can't do this.
> My desktop is mate and the window manager is lightdm and I found no
> place where I can change this from 10 minutes to maybe 2 hours or longer.
> I hope someone can help me. I think this must be a file under /etc or
> something like that.
>
> Greetings Frank
> _______________________________________________
> Dng mailing list
> Dng@???
> https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
>