XScreenSaver 5.14

XScreenSaver 5.14 is out now, because I'm sick of getting email about 5.13. Turns out I introduced a bug that only happened if you were using "Blank Screen Only" mode and had Power Management turned off. So the bug happened if you installed XScreenSaver -- the key words here being SCREEN SAVER -- and then configured it to not actually run any screen savers, and also, not ever power your monitor down. That's right, make sure it's displaying that black screen at peak voltage, boy howdy! Who would do that? Apparently almost everybody. And they all sent me mail. So here's the fix. Though I strongly recommend that if you're not running any of the actual screen savers that come with XScreenSaver, that you just uninstall it and stop wasting my time and yours. You kids get off of my lawn.
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15 Responses:

  1. gheorghe says:

    Probably a default setting?

  2. Zygo says:

    If you have a display device that has a cow when you turn off DPMS (like certain TV sets, alas, which respond to "DPMS off" events by automatically switching from whatever you were watching to the PC input, then realizing there's no signal there and displaying a big ugly "NO SIGNAL" box), and you don't want to waste CPU displaying something that isn't black (since you can't see it because you used your TV remote to turn off the display), but you do want the password lock feature (to protect the Interwebs from your 1337 hacker cat), and you had xscreensaver installed--that's exactly the configuration you'd end up with.

    • jwz says:

      Shut up. I never should have added the locking option in the first place.

      • Zygo says:

        Surely someone has come up with a screen lock program that doesn't have to live inside, and can coexist with, a screen saver? Or do those things already exist, but have to be separated from GNOME and KDE?

    • Andrew Wilcox says:

      My telly set has a typical VGA input in addition to the RCA and HDMI and WTF and LMNOP and all those other acronyms that I don't care about since I'm a computer geek, not a videophile.

      That said, when my Linux box sent DPMS off, the telly actually /turned itself off/. Even if I wasn't bloody using VGA, and was instead watching something on the DVD player (which, ironically, my Linux box doesn't have a drive for).

      tl'dr If you have a computer hooked up to a television of any kind, for God sakes turn off DPMS. And yes, jwz, I much appreciate this release. Thanks!

      • jwz says:

        You are running a screen saver with no screen savers. Get off my lawn.

        • Andrew Wilcox says:

          For what it's worth, when I noticed the bug I just set it to BSOD. Now when I have friends over and we want to watch something, they are greeted with Atari bombs and DSErrors -- much classier than a black screen, and I get the added masochistic pleasure of seeing 68k crash dumps in high definition!

  3. Chris Lawson says:

    I am bookmarking this under "Extreme schadenfreude"

  4. Uh, a "screen saver" is something which is intended to save a CRT from burn-in. It has become bastardized over the years into "an application which chews unnecessary CPU doing expensive mathmatical calculations [seti@home, GPU wanking]."

    A modern-day LCD that's "normally black" shouldn't use significantly more juice regardless of the DPMS power management setting of the display if it's displaying a blank/black image. However, some crappy displays (like my 53" LCD TV) have a really annoying lag waking up from standby -- long enough that, personally, I turn that DPMS shit off so I don't have to wait for it.

    A screen saver should save the screen from burn-in. Programs that do anything else but call themselves screen savers, are just misnamed.

    • jwz says:

      Really?? Is that what a screen saver is?? You must be a lot of fun at parties.

    • Adolf Osborne says:

      I see your point, but you're still wrong.

      Screen savers were never really -needed- on displays in common use, to begin with, on a graphics display: Even way back when, common use usually presented enough randomness to avoid burning the phosphors into identifiable areas of bright/less bright. Most problems of screen burn, even back when monochrome text-based terminals were all the rage, were because the screen displayed the same thing forever.

      And in the event that the displays are not sufficiently random (suppose you spend all day, every day, running Autocad or some accountancy program or whatever), the display burns anyway.

      The concept of a "screen saver" has been thoroughly debunked now for decades. It's not needed, at all, and seldom has been.

      And the whole point of Xscreensaver is not to "save screens," as black (or off) would do perfectly fine for that. The point of Xscreensaver is to be pretty.

      That all said: Plasma displays are still prone to burn-in, and are not much different from CRTs in this regard. LCD displays are still prone to burn-in (though we call it "image retention" these days).

      At work, I have several large plasma screens which are badly burned with security imagery. They display the same set of security camera feeds 24x7. They are burned, just because it's not practical to have them do anything else.

      And regarding LCD "image retention," I have a few, rather nice, Elo rackmount LCD touchscreen displays used for dispatch operations (with IPS panels), which are also badly burned ("image retained") and/or distorted from displaying the same image almost 24/7 for years and years.

      Xscreensaver won't help these problems that I'm experiencing, because in these applications a display -must- have mostly the same image on it 24x7. But, as I said, it's not intended to: It is meant, AFAICT, to be pretty.

      A "screen saver" need only turn off a display automatically to be effective. Periodic random displays don't help at all.

      (Oh, yeah: The big Panasonic professional plasmas I spoke of earlier do have functions to wiggle the display around periodically, one pixel at a time, to soften the edges of the burn which is inherent to the application. This works a little bit, and isn't very intrusive to the end user.

      They also have a function which can do an inverse-burn, wherein the display spends some time attempting to burn the display evenly by inverting (black = white, magenta = cyan, etc) colors on a schedule. This is not enabled at all, because it makes the display largely useless for its continuous security application, but it is in essence a perfect "screen saver".

      My Pioneer car stereo, with its OLED display, has the same inversion function, for the same reason.)

      • "The point of Xscreensaver is to be pretty."

        Then rename it to Xeyecandy, and stop misleading people as to what it actually does.

        "Xscreensaver won't help these problems that I'm experiencing, because in these applications a display -must- have mostly the same image on it 24×7.

        Indeed, a traditional screen saver wouldn't help--as you point out, you can't actually use one--HOWEVER, specifically, security video applications should absolutely implement (and most don't) in their viewer portion a periodic jitter, where the image displayed is shifted left, right, up or down by 5-10 pixels, so that the image is still displayed and "the same" (less literally a handful of pixels) but in a slightly different position on the display so that image retention doesn't happen.

        • jwz says:

          What the hell is wrong with you?

        • Adolf Osborne says:

          If you feel that strongly about it then just change the name of it yourself.

          What's stopping you?

          (Oh. And thank you for reiterating the same point I'd already made, and somehow still managing to get it wrong: Moving the picture around just smears the retained image; it does not magically eliminate the problem.)