Screen is not prevented from dimming when watching videos

[pinumbernumber]

I'm running Linux Mint 17 Cinnamon x64 on a Lenovo Thinkpad T400.

What you did for the problem to happen, and how to reproduce it:
* Enable the "on battery, dim the screen" option in Power Management.
* Be using battery power.
* Watch a video (VLC, the built-in Videos app... it doesn't seem to matter).
* Observe that the screen dims.

What happened:
* The screen dims, despite the video playing.

What you expected to happen instead:
* The screen should not dim when a video is playing.
* (I assume this is because a video is not "counting" as activity in the eyes of whatever makes the decision to dim.)
* Other power management systems (screensaver, sleep) are correctly inhibited.

If the problem happened once, sometimes, or always:
* Always.

====

Manual workarounds:
* Disable the "dim the screen" option (but this is inconvenient since you'd usually want this on, and changing it before and after watching videos is even more inconvenient).

[ofb (cottlestonpie)]

In app called "Videos", the preference "Disable screensave while playing" does not work.

I tired both preference options: "Video" and "Video or Audio".

My screensaver prefs are Blank screen, activate after idle for 20 minutes, and Lock screen.

System: Host: glam Kernel: 3.13.0-24-generic x86_64 (64 bit) Desktop: N/A Distro: Linux Mint 17 Qiana
Machine: Mobo: ASUSTek model: M2NBP-VM CSM version: 1.xx Bios: Phoenix version: ASUS M2NBP-VM CSM 0301 date: 09/26/2006
CPU: Dual core AMD Athlon 64 X2 4200+ (-MCP-) cache: 1024 KB flags: (lm nx sse sse2 sse3 svm)
           Clock Speeds: 1: 1000.00 MHz 2: 1000.00 MHz
Graphics: Card: NVIDIA GF119 [GeForce GT 520]
           X.Org: 1.15.1 drivers: nvidia (unloaded: fbdev,vesa,nouveau) Resolution: 1280x1024@60.0hz
           GLX Renderer: GeForce GT 520/PCIe/SSE2 GLX Version: 4.4.0 NVIDIA 331.38

[ofb (cottlestonpie)]

Have tested 3 boxes now. This bug affects Mint Mate 17 64bit and 32bit.

[Feels Warrior (feelswarrior)]

Currently using Cinnamon Mint 17 64-bit and it affects me too.

If I recall correctly this bug has been around ever since I started using linux mint a few editions ago. Hope it gets fixed once and for all.

[Artiom (ar-molchanov)]

The same in LMDE. Only SMPlayer works like expected.

[ALinuxUser (buntulongername-new)]

I have this too, on Cinnamon 2.8.6, and it seems kernel-independent and indeed also occurs on AC (not just battery) power.