KDE 4.3 - Display Power Management interferes with video playback

keerthi · 2009-11-21 10:57:39

So here is my settings:
1. Screensaver turned off under System Settings -> General -> Desktop -> Screensaver)
2. Display Power Management turned on; set to 'Power off after 10 mins' under System Settings -> General -> Desktop -> Power Control)

This works as expected under normal working conditions but gets rather annoying while watching movies. I tried with VLC and smplayer. Both the players doesn't stop the screen from going blank after 10 mins. Is this how it always works in KDE? (I'm new to KDE)

I'd prefer the display remains on while watching movies. Is there a player that suppresses the display Power management settings temporarily during playback. Am I missing something? Thanks.

Bralkein · 2009-11-21 22:27:19

Hi, I am running KDE on my laptop, so I think power management might be a bit different for me if you're running a desktop, but I will tell you how I would do it and maybe it will work for you too.

Well first of all it is best to control display power management through System Settings -> Advanced -> Power Management, then you can configure display energy saving for different power profiles. This way, you can set up different power profiles for different purposes. You could go to Edit Profiles, add a new Video profile to the list, and disable display power management for that profile. Once you have created the profile, you can switch between profiles manually.

To manually switch between profiles, add the Battery Monitor widget (hopefully it still works on a desktop PC with no battery, if that's what you have) to your panel or desktop, whichever you prefer. Once that's added, you can manually change power profiles by clicking on the widget and using the drop-down menu to choose the one you want.

(Skip this next paragraph if you feel writing a script is beyond your ability/you can't be bothered)
Obviously this is not perfect, because of the manual switching of profiles required. If you know how, you could probably write a script you can click on which changes the power profile, launches your video player, waits for the video player to close, then switches the profile back to the normal one. Alternatively, your video player might possibly support some kind of scripting interface which will allow you to do this, but I don't know for sure. Either way, it would be pretty simple to achieve this; the power profile can be controlled by DBus, just fire up qdbusviewer and look at org.freedesktop.PowerManagement/modules/powerdevil and it should be easy to figure out how it works (there is a command-line tool to send dbus messages you could use in a script).

Maybe there is an easier way of managing it than going through all of this rigmarole, but I have yet to discover it I think there is a way to suggest features on the official KDE forums, you could go and take a look if you have time.

Last edited by Bralkein (2009-11-21 23:58:27)

Gen2ly · 2009-11-21 23:04:16

Very nice. Yeah that's the way to do it. I've had to do this too since I regularly watch shows on my computer. I found a good way for me to do it was to write a script that toggled display pm and inhibited suspend:

http://linuxtidbits.wordpress.com/2009/ … h-a-movie/

keerthi · 2009-11-26 01:36:41

Thanks for a detailed post. And thats how I have it set up.

For now, I'm using the movietime hack. But I feel that KDE should do this automatically.

Arch Linux

#1 2009-11-21 10:57:39

KDE 4.3 - Display Power Management interferes with video playback

#2 2009-11-21 22:27:19

Re: KDE 4.3 - Display Power Management interferes with video playback

#3 2009-11-21 23:04:16

Re: KDE 4.3 - Display Power Management interferes with video playback

#4 2009-11-26 01:36:41

Re: KDE 4.3 - Display Power Management interferes with video playback

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