When I use VLC or other media player, I can watch the movie until the end without touching the PC. If I watch a movie on YouTube using Chromium or Firefox my screen will turn off as is set in System Settings > Brightness and Lock. How to prevent this without to change the settings in Brightness and Lock.
Edit:
- My Ubuntu 13.04 with Gnome 3.6.3.1 uses gnome-screensaver (I didn't installed any other screensaver).
- Any of the answers from this question didn't worked for me in 13.04: How to prevent my screen from dimming when watching YouTube? - this question is related in 12.04.
