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I have noticed that mi screensaver doesn't start while I'm watching videos on YouTube. I'm using Windows 7.

This is the test:

  1. Set Windows screensaver to 1 minute.
  2. Browse to YouTube and play a video longer than 1 minute; ideally much longer.
  3. Note that your screensaver doesn't come up after the specified time (1 minute).

I've tested using Firefox, Chrome and IE8. My Flash Player version is 10.3. (Youtube is using flash to play the videos). The same happens whether I watch the video in full-screen or not.

Does anyone know how they do it?

I've searched but all I found was people saying it's not possible, or tips for users to disable their screensaver while watching videos.

Please review all answers. Don't stick to the most voted.

JulianG
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  • See http://support.microsoft.com/kb/126627 – Rohit Sharma Oct 09 '11 at 10:14
  • You can't call system library(user32.dll in this case) functions directly from flash. – Darcara Oct 09 '11 at 10:24
  • You can't call user32/native-library from the compiled .swf for security reasons but flash player is a library installed on your computer (if this was not true then there'd be no remote vulnerability with flash - http://www.checkpoint.com/defense/advisories/public/announcement/2011/140311-cplm-2011-079-adobe-swf-in-excel.html). I don't work for Adobe but other than this there is no documented way of disabling screensaver, alternatively the codec built into flash player can disable screensaver if not the library itself. – Rohit Sharma Oct 09 '11 at 11:35
  • Thanks for your comments. I read http://support.microsoft.com/kb/126627. Unfortunately I don't know what language that is and what environment they're talking about. My video presentation runs on a browser window. Is that VBScript or something like that? – JulianG Oct 09 '11 at 17:23
  • In Firefox, it's actually a [known bug](https://bugzilla.mozilla.org/show_bug.cgi?id=517870). – jamix Apr 03 '13 at 20:42

3 Answers3

7

Someone outside StackOverflow pointed me to this article: http://www.webkitchen.be/2010/04/13/6-lesser-known-features-in-flash-player-10-1/

Disabled screen saver in full screen mode

There’s nothing more annoying than having to press the keyboard or moving your mouse every few minutes to prevent the screensaver from kicking in while watching a video in full screen. Flash Player 10.1 now temporarily disables your screensaver if video is playing and not paused, stopped or buffering. But it also works with audio. So… if you’re running a full screen app that plays audio and it is not paused, stopped or buffering and actually has volume the screensaver will not kick in.

Unfortunately I cannot find an official Adobe source for this. They seem to be so focused on Flash Player 11, that they removed the list of "new features" available since Flash Player 10.

I tested this and it works whether in full screen or not, as long as a video is playing.

I guess the answer to my original question is NOTHING. Flash Player, not YouTube, does it automatically.

Community
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JulianG
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1

I found some documentation at help.adobe.com - Playing video in full-screen mode:

Flash Player and AIR allow you to create a full-screen application for your video playback, and support scaling video to full screen.

For AIR content running in full-screen mode, the system screen saver and power-saving options are disabled during play until either the video input stops or the user exits full-screen mode.

Kamil
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0

It looks like a Microsoft bug, as mentined below, you can make your presentation in a browser to prevent screensaver. Hope this link helps.

From Issue 9853: Display blanking fails when Chrome has focus:

Comment 8 by *ida...@chromium.org, May 21, 2009
Took some time to look at this and I can confirm that it is easily reproducible and the Chrome does not do anything to affect Windows power management. It really looks like a Microsoft bug which is clearly triggered by Chrome having focus.

To be clear what actually happens is that the 'Display-blanking' power-state does not trigger while Chrome has focus, all other power-states (Suspend, Hibernate) trigger. The screen saver also triggers.

Joachim Sauer
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ymutlu
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  • Thanks, but I stated that I observed the issue in multiple browsers not just Chrome. – JulianG Oct 11 '11 at 17:19
  • I'm sorry ymutlu. I've just tried the same thing on MacOS using Chrome. Screensaver is being temporarily disabled while video is playing. – JulianG Oct 12 '11 at 08:10
  • I've just tested for that "problem" and my Windows 7 turns the screen off and/or displays the screensaver with a focused Chrome window, yet it won't display the screenscaver if a Flash video is playing. – JulianG Oct 12 '11 at 08:26