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Building a Video Wall out of Old Laptops?
alphakappa asks: "I am interested in building a video wall as a personal project using recycled old laptops so that I can make use of the display controllers that are already present. Is there free or cheap software that can extend the display on Windows and still be capable of showing different videos on different zones (like, say run a video in one zone while showing a powerpoint presentation in another one) What tools would you use?"
Each old recycled laptop will have a different color scheme, brightness and viewing angle. DSTN vs. TFT, relative strength or weakness of the backlight, etc.
yes, yes, I am a troll for mentioning all this, blah blah blah
I want to delete my account but Slashdot doesn't allow it.
Buy a wall of macbook pro 17's. say, 96 machines.
load the movie into quicktime on all 96 machines.
press 'play' on the IR remote.
Profit!
wait, wat was the question? oh yeah, silly.
Buy a projector for $1000 and be done with it. The display controller is part of the motherboard, so you would need the entire laptop, not just the display. Thus the power consumption would quickly increase since you're powering entire laptops. Also, the lead length between the panel and the onboard controller must be very short - just a couple inches. So the bulk of the laptop will have to be mounted right with the panel. The displays will look significantly different - particularly with respect to white (some will have a yellow tint, others a blue tint), If you sit down and add up the bandwidth - full motion video at say 1024x768, times however many laptops you're driving, equals a crapload of bandwidth. We're talking gigabit requirements. If these are old salvaged laptops then you'll be lucky if they even have 100Base-T.
As I said, buy a projector for $600, plug it in and enjoy.
Dan East
Better known as 318230.
This really doesn't seem feasible, unless you have some serious hardware engineering prowess. What it seems like you want to do is span the laptop video on multiple monitors? If you want to do this with 'external' displays, then the problem is spanning across those individual laptops. With network access, you might be able to fudge something with VNC (although, don't expect great speed on that). Otherwise, I'd say probably not. From what I know, most of those art displays using regular PCs/monitors used specialized software or particular effects not available in a standard configuration to do what they do.
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I've not used it myself, but some friends have and it worked pretty well. http://www.maxivista.com/ Also perhaps you could bug the synergy team (this is an open source project), although I don't think this feature is something that will be implemented anytime soon... http://synergy2.sourceforge.net/ Though if you just want to control all the computers from one place, then synergy should work.
Why would it be a requirement that the software has to run on Windows if you're using the laptops sole ly as displays? Even if you'd like to use the display with Windows, the laptops would be able to run whatever you like.
Then you have a server that throws X applications onto the laptop displays where you will get just about any look&feel you like.
OK, it's crude and may require some work. The laptops may never be a really good solution anyway. Also consider the cost of additional hardware involved and you may be better off with a good projector or "standard" flat-screen LCD:s connected to a single computer with multiple graphic cards where you stretch the desktop to cover multiple monitors.
It's possible to run multiple monitors under both Linux and Windows without any problems.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
Well, you will need to mount the whole laptop to the wall, and run power and network to each laptop. Each laptop will look a bit different, and laptop displays really aren't meant to be running 24/7, so plan on replacing the laptops with some frequency. That means that the physical build aspect of a project like this won't be insignificant to make it all work smoothly, look nice, be easy to maintain, etc.
Another poster has mentioned a projector. This is certainly the more sensible option, but for a funky project for its own sake, I'll assume that you just want to go with the laptop wall anyway.
First off, don't try to do this with Windows. It'll work very poorly. As for playing videos, you can ssh into each laptop and run mplayer locally to get any gioven laptop playing a video. For multilaptop video playback, you will need to make yourself some scripts that will log into each laptop and run mplayer using appropriate cropping options on the video so that only a portion of it is played full screen on any given laptop. You may also want to check out VLC's network streaming options. You will need quite a bit of bandwidth. I sometimes have issues playing high bit rate video files over my 100 Mb network with just a switch between the client and server, and no other significant traffic. You will also want to avoid any HD. If you are going to build something for playing serious high bit rate HD across 9 or 12 different systems, you don't need to ask slashdot how to do it.
Past that, you probably want to write some additional scripts to do things like randomly show your favorite online scenic web cams, give weather reports, show traffic conditions. But, you are creating custom hardware, so don't look off the shelf for that sort of thing. You pretty much have to roll your own, because there isn't any standard plug and play interface for video walls.
Good luck.
I had always thought doing something similar to this, but in my dining table. I figured it'd be possible to take one or 2 flat panels and some miscellaneous optics and make a fairly seamless representation of the image appear to be under the glass. Kind of cute if you whack a remote controlled webcam under there and show up your guest's skirts at dinner...
My first though so far was to use mirrors - reflect the display off a mirror kind of like what they do in some of the arcade games. This lets the display appear further from the observer than it really is - hence saving space. You could build some kind of optics system like that for your project to project a reasonably seamless image (apart from colour and size of the images).
I drink to make other people interesting!
http://puredata.org/, and it's library http://gem.iem.at/ could be run on the laptop array. Building a laptop hierarchy: 1 laptop recieves the whole 1024*768 and GEM slices four 512*384 screen displays and serves them to a 2*2 grid of laptops on display. or, if you have 21 laptops, you can make a 16 laptop laptop display wall wall. The trick is farming low resolution chunks to the slower machines. The final 4*4 laptop wall only has to have a combined resolution of 1024*768, right? You're not going to get highdef out of this wall.
with rocket fuel siphoned straight offathe rocket my eyehorn glows
Or you could build a wall of OLPC's!!! just grapple them away from those pesky kids who wouldn't use them anyway!!
The major cost of projectors is in the bulbs. A $600 projector that takes $300 bulbs that only last maybe 2000 hours is no fun. When you have the $300 bulb on your mind you get really stingy about turning the TV off all the time. To get around this, there are about two solutions.
1. Build you own projector, and spec a better cheaper bulb that lasts longer
2. Buy something like the LumenLab Evo which takes $30 bulbs that are supposed to last 6000 hours.
I went with option 2 because I'm a lazy bastard. While there are better projectors with higher resolution, for now (I graduate in 3 weeks) it was worth every penny and then some.
Even those who arrange and design shrubberies are under considerable economic stress at this period in history.
No, it's not what your looking for, just interesting and informative regarding the technical problems.
HIPerWall is a 200 Megapixel display, based on 50 Apple 30" Cinema Displays driven by 25 Dual G5 PowerMacs plus one controller. It's a project at the University of California to explore very high resolution displays. HIPerWall is short for Highly Interactive Parallelized Display Wall. The PowerMacs are connected and act as one large display, allowing even video to be split over the whole area. The main problem they seem to have solved is the software to split the display over several separate machines, a problem you will also have if you try this with Windows and laptops, therefore this might be a good place to look for some experience. Apple has a nice project description in their science section.
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Isn't it the case that with laptops, the screen is usually the first thing to break?
Only three things are certain; death, taxes, and apocryphal quotations - Ben Franklin.
I've tried XDMX on exactly this setup. I had a number of old laptops, (nine to be exact), that I converted to
one large X display. Worked really well. The screen was huge - 3x3 17" laptop screens adds up to a big display. The downside? You have to have a dedicated switch to handle the traffic, (because there is a LOT of traffic - even when moving the mouse the switch goes bonkers). Also, it's slow. Much slower than an individual display, but good for displaying static images.
Once I had it setup I didn't use it much, and in the end just used each laptop as an network mp3 player in each room of the house. Much better use for them.
-- main(s){printf(s="main(s){printf(s=%c%s%c,34,s,34
Let's assume this is a "because it's there" hack, because as others have pointed out, if all you want is a large video screen, you'd be better off spending the time doing a McJob and spending the proceeds on a projector.
So, you're doing it because it would be kinda cool. Have a play with GGI. It's a portable graphics layer with various targets implemented. e.g. there are kernel targets for various graphics cards, a Windows target, a VNC target, etc.
What'll interest you is the display-tile target, which is a proxy target that splits its input into tiles and forwards them to a set of other targets.
So:
- find the most efficient way you can to display video on a GGI target. Mplayer can do it. here is a screenshot of mplayer tiled across a load of X windows via display-tile.
- Set up each of your displays to be a GGI target that your central box can display to (be it VNC, X, or something more original)
- configure display-tile to forward the right tiles to the right targets
- point mplayer at display-tile
- profit!
The tiles don't have to be a regular size. I'd quite like to see a video wall made up of various sized screens - a 32" TV here, a 17" monitor there, a PSP there, etc... maybe a vt100 in there displaying the aalib target...
Fun!
Oh wait... you said windows. Never mind.
I would definitely not try to tap into the video systems for the laptops; keep the whole machine, unhook the hinge, and get a long-enough interconnecting cable to let you flip the display and mount it face up over the keyboard. Yank the hard drives and let the machines boot off the network. Have them all running VNC so you can control them remotely. If they're old laptops you'll want a codec you can detune a bit so it plays the video you want well enough. You'll also need to adjust brightness and color temperature to make the displays more or less identical to the viewer.
by a cluster computing group at the University of Kentucky called the Aggregate http://aggregate.org/. They built a nine laptop display panel that is basically what you are trying to do. It is much more difficult than I thought it would be to do. Here is a video of the panel in action http://aggregate.org/IMG/mvi_5158.avi. And here is the software they created to do it http://aggregate.org/VWLib/.
> "I am interested in building a video wall as a personal project using recycled old laptops so that I can make use of the display controllers that are already present. Is there free or cheap software that can extend the display on Windows and still be capable of showing different videos on different zones (like, say run a video in one zone while showing a powerpoint presentation in another one) What tools would you use?"
Linux (actually this is a simple designation for GNU software, X.org server, KDE/Gnome DEs, of course, the Linux kernel, but more importantly the OS development process centered on the kernel).
Ah, Windows, you asked? Aham, go to www.microsoft.com . Only they can help you.
But, from my experience, let's say I'm gonna train my pig to chase falcons before it happens.
Good Luck.
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// forever!!!
Apple
I work in the Electronics Visualization Lab at University of Illinois Chicago, and we have a software to deal with tiled displays called SAGE.
http://www.evl.uic.edu/cavern/sage/index.php
It also works with VLC. Might be worth a look for you.
There is a fellow running a computer recycling center in Oakland, California who brought to the May 2006 MakeFair in San Mateo a rolling wall with a 9 monitor display. The display was one image partitioned among all 9 displays.
The base of his system was a 3 shelf display rack with casters. It is a common commercial shelving unit.
On the cart he put 3 rows of 3 CRT monitors. Each row of 3 monitors was driven by a salvaged pentium class computer, and each computer had 3 video cards. The video cards pick up an address from the slot they are plugged into, so the video software could send the correct 1/9th part of the image to each display.
The three computers were connected with ethernet cable. The three computers all run linux and X display software. Ethernet is plenty fast enough even on old machines for feeding the displays.
One of the computers was the master. Now what was the software? It was something generic associated with the X display software system but not well publicized. Maybe it was mplayer (which does a number of remarkable video reformatting stunts). See the mplayer documentation files. I remember, he was not using "dual head" video cards (which I have found rather problematic), he just used junkbox video cards and addressed them by slot number. I think X itself has multiple displays in the XF86Config file.
In summary: he had a striking "wall size display". It was portable. It was built using any generic Linux and X. It used recycled computers, video cards and CRT monitors that are available in abundance.
Recent versions of XOrg have DMX (Distributed Multiheaded X) which makes a bunch of separate X servers (usually on different computers hooked up over an ethernet) behave as a single X server running multiple monitors. You run an X server on each machine to run it's display(s), and DMX on one machine to tie them all together. All apps "display" to the DMX X server, and it sends the appropriate info to each "real" X server for display. If you're doing some massive OpenGL stuff and it bogs down, Chromium is supposed to filter the OpenGL so each screen only gets the OpenGL info it needs, otherwise it's sent to all screens.
By default, these screens aren't treated as one large screen, they're a bunch of separate ones. Enter Xinerama. This makes the screens act as one large screen in the shape you specify (usually square, but they could be all in a line or probably even L-shaped or T-shaped.)
I have not used DMX, but recently hooked 5 screens to a single PIII-800, using 5 Nvidia TNT2s. These were all in a left-to-right line. The OpenGL screen savers ran like crap (since I was not uses the NV driver, so no 3D acceleration..) but everything else worked great. DMX looks VERY easy to setup. I actually had 7 heads hooked up, but the (AGP) dual-head G400 didn't play nice with the rest so I left it out.
*DON'T!!!* use a bunch of laptops/notebooks for this screen. If you don't already have them, the used market for them is stupid expensive, they're highly unreliable, and as others have said, the appearance will be very ugly and non-uniform. These will not have ethernet, so you'll have to dig up a bunch of PCMCIA cards and dongles, or god forbid run wireless.. you'll run out of bandwidth quick that way 8-). They might not have fast enough video hardware to play full-screen videos either. Cheap ones tend to have like 8-32 megs of RAM too. You probably can't even get a P2 notebook for what a used LCD will cost you, and you can get LCDs that are more uniform in appearance, even if they aren't the same brand. If you're running even something large like a 6x6 grid, you could run this off 6 desktops if you get some with 6 PCI slots (or 5 PCI and 1 AGP) and old video cards. A 3x3 could run off just 2 computers. You could cram even more screens per computer if you want to run dual-head cards.
http://wiki.videolan.org/Documentation:Play_HowTo/ Advanced_Use_of_VLC#Wall_video_filter
VLC will work. Check out the link Wiki page that describes how to do it. It's also free =)
Hi this is an interesting bolog but i was wondering does anyoneknow how to make an old laptop monitor (not conected to a laptop) be used as a monitor for a video game system, I am trying to modify the old N64 with a old laptop screen, if anyone can help me that would be great thanks