DIY Video Wall

[hunterjwizard]

I'm a bit of a hardware hoarder and have recently realized that I am in possession of no less than 6 identical 17" 4:3 Dell computer monitors, and just came across a cheap source of wall mounts(http://www.tykesupply.com/Accessories-Center_Mount_for_70_series_monitor_stands.html $13 if anyone is interested). I have this idea to attach them into a sort of giant video wall that will display a singe source over all 6(in a 3x2 grid it would be about the size of a big 16:9 TV)

I know this isn't going to look great, the entire function here is just to have a little fun and use up some excess hardware(17" 4:3 monitors are very easy to come by these days, and practically free). Also the display will let me pretend I'm living in a 90s action movie, and everyone loves that.

Anyway, I am familiar with the "junkyard jumpotron" project (http://c4fcm.github.io/Junkyard-Jumbotron/), but that would require having all 6 screens hooked up to one or more desktop computers - not really the goal. I'm hoping to find a software solution where I can basically feed a video signal in from a variety of sources and have it show up. But I'm not looking to spend thousands or even hundreds of dollars on this project.

i do apologize for this rambling and kind of awkward post, I've just made a hobby out of seeing exactly how many LCDs I can use and it never gets old.

Thanks!

[jagabo]

It might be cheaper for you to just buy a 45" HDTV.

Get three graphics cards with two (DVI?) outputs each. Or two graphics cards with three outputs each (harder to find). Or Matrox makes wall-of-monitor devices specifically for this purpose (not cheap). Calibrating all six monitors will be a hassle.

[hunterjwizard]

It might be cheaper for you to just buy a 45" HDTV.

That's what I was afraid of. I don't honestly care about the resolution or quality. I remember, for example, seeing displays that involved a stack of old-style tube TVs all displaying an image across them, I'd be just fine with an RCA/SVideo solution.

All right, so assuming I do have to wire all this through a computer, do you have any suggestions for an easy way to run a video source in to it? Like a TV capture card or something, but the output is always a problem. I've never been able to find a program that would just take the signal from the card and display it on the screen easily.

[jagabo]

The Matrox TripleHead2Go can take the output of a single graphics card and spread it across three monitors. With two of those you could split the outputs of a single dual DVI graphics card across six monitors. A pair will cost you about $600. Of course, you'll need 8 DVI cables.

You can probably get three graphics cards with dual DVI outputs for less than $250 (if the motherboard has 2 DVI outputs you'll only need 2 graphic cards). Of course, you'll need a motherboard with enough slots. You'll need six DVI cables.

I don't know much about analog (composite, s-video) solutions. I don't think you'll find such devices new since nobody would do that today (and it requires that the input signal be digitized, split into six outputs, then converted back to analog video -- so it's no easy task). You might find an old used device somewhere.

[Cornucopia]

I'm with jagabo on the technique (Matrox DualHead2Go or TripleHead2Go, Dual dig Vidcard), though this may be a bigger project than you would like.

Think about this: were you intending to show a single image that spans them all (as in a triptych) or were you duplicating screens. I would assume the cooler, video-wall-like display you were hoping would be the former.

If so, remember that each monitor might have, for example like my 17" Dells, 1200x1024 max native resolution. A dual-dvi (or dp) card that is set for over/under span, then piped each to a triplehead-to-go would give you 1200*3 x 1024*2, or 3600x2048. This is close to the max available for the higher end nVidia cards (4k, or 4096x2160) and at 1.757DAR it is quite close to 16:9 (aka 1.77) DAR, so that should work. But that 4k is pretty taxing for the card and the computer (equivalent to running 4 HD videos simultaneously). So you'd need a very beefy computer.

I don't think analog is really going to help you much here. Part of the coolness factor of a videowall is in the combined massive size & sharpness of the whole thing, and that requires digital inputs (dvi, hdmi, dp) and using native max resolution of the monitors.

Even dropping it down to its lowest possible level monitor res (640x480) would still give you a 1920x960 span that needs to be filled. Less beefy PC, but still not ordinary, particularly the Vid card. Wouldn't save you much.

Scott

[hunterjwizard]

All right, thank you all for the input. This is looking to be quite a bit more money than I'd like to spend on a little pet project. I'm going o dig through my hardware and see if I have two dual head PCI cards(I might) but its not

I've actually spread got a triple head to go, incredible piece of equipment. I just want more screens. Can never have enough, you know?

[Bjs]

Raspberry Pi project here

each monitor needs a raspberry pi, and one as a master controller ... for video

Gaming, via dvi out needs wireless display adapter and master pi to have receiver ... have fun

[Cornucopia]

Yeah, that PiWall might be the cheapest solution: $35/each for 7 B+ version cards, then ~$50 for a 8portGigabit network switch + 7x Cat6 cables, and the cost of 7x 2GB+ SD cards (~$5/each). For something that close together, makes little sense to use wireless - wired is more practical, better performance.
Then there's 6x HDMI->DVI adapter cables (~$7/each).

That's ~ $375-400 USD, if you shop smartly (not counting tax, shipping, etc).

Then you've got to know how to work with Linux.

Still, more possible than I would have expected.

Scott

[hunterjwizard]

The PiWall is still expensive, though I already have the bulk of the needed equipment(1 rasbery pie and nearly all the cables/switches/SD cards/etc)

AND it has the huge advantage of being a pretty interesting project. I'll look into it a little bit more, its certainly the most cost-effective solution. And hey if it doesn't work out the pie has about a zillion and one uses.

[jagabo]

Raspberry Pi project here

Nice find. Hadn't seen that before.

[jagabo]

The PiWall... its certainly the most cost-effective solution.

I disagree. If you have a suitable computer already, 3 dual DVI graphics cards (or 2 cards if the computer already has dual integrated video outputs) is cheaper and easier.

[hunterjwizard]

The PiWall... its certainly the most cost-effective solution.

I disagree. If you have a suitable computer already, 3 dual DVI graphics cards (or 2 cards if the computer already has dual integrated video outputs) is cheaper and easier.

True. It doesn't have to be DVI, and I have a handful of dual-headed PCI cards as well, so setting it up that way is probably doable with existing hardware(I have a lot of crap lying around). I might end up doing that anway just for giggles, and because I wouldn't have to buy anything new.

But in my case it comes with a few disadvantages.

One is that I'd have to have the computer nearby. Currently my machines are in another room, while my workstation(monitors, keyboards, mice, etc) are connected via 50ft cables running through a wall.

Of course, my ultimate goal with this project was to have it be OS-independant. Really, i wanted to be able to feed any source into the wall and have it play(not just be the desktop of a computer.

Anyway, I'll figure something out as I continue pottering about with my equipment.

[jagabo]

Of course, my ultimate goal with this project was to have it be OS-independant. Really, i wanted to be able to feed any source into the wall and have it play(not just be the desktop of a computer.

Whether you use Raspberry Pi or a Windows PC you'll need a capture device to capture a video source and software to put that video on the screen(s). Some media players, like VLC, can get video from a capture device and display it.

[hunterjwizard]

Of course, my ultimate goal with this project was to have it be OS-independant. Really, i wanted to be able to feed any source into the wall and have it play(not just be the desktop of a computer.

Whether you use Raspberry Pi or a Windows PC you'll need a capture device to capture a video source and software to put that video on the screen(s). Some media players, like VLC, can get video from a capture device and display it.

Hmmm, I shall have to explore this feature in VLC. Video wall or no video wall, this is a feature I've been looking for for quite some time.

[Bjs]

Project website includes additional scripts for pwomxplayer which provides presets to allow screens to only show a predefined portion of video.

Vlc would need to support similar if it was to work.

Without a computer ... never say never ... for now, not happening.

[hunterjwizard]

Well there are devices like this http://www.ebay.com/itm/DVI-VIDEOWALL-9X-9-Display-Video-Wall-Processor-/221047574422?...item3377764f96 that do it without a computer... but I'm really not interested in spending $8,000 on a project that is quite litterally just for s**ts and giggles. I'm just doing this for fun, I really appreciate all the discussion and suggestions.

[Cornucopia]

The point you might be missing, but which is staring you in the face is: you have COMPUTER monitors. So, you'll need a computer of some sort to supply them.

Those devices are glorified versions of the Matrox Dual & Triplehead types (aka "splitter/distributors"), or they are glorified black box versions of a custom PC+splitter/distributor. Either one needs a "PC". Even dedicated industrial-strength devices such as this: http://www.planar.com/products/processing-players/vcs/ are just PCs at their center.

Scott

[hunterjwizard]

The point you might be missing, but which is staring you in the face is: you have COMPUTER monitors. So, you'll need a computer of some sort to supply them.

You know... I can't deny your logic. In fact I actually feel kind of silly. lol.

I love this forum, I really appreciate the warm welcome

[Clockwork]

There's nothing about this project that can't be solved by throwing piles of cash at it. Don't stop now.

[hunterjwizard]

There's nothing about this project that can't be solved by throwing piles of cash at it. Don't stop now.

That's the same as every project, thoguh, lol

Actually I found an even cheaper wall mount on amazon, $8 with free shipping. I know I have at least 2 dual-headed(not DVI but good enough) PCI cards lying around, and more than enough computers and cables. So For the investment of around $50 I could get this thing running.

Now I just have the answer the age-old question of "Why?"

And... I find myself unable to compose any answer beyond "why not?" and then clicking "buy" on my amazon.com shopping cart. I'll post pictures when I'm done. I'm currently picturing a sort of free-standing 2x3 unit that will have a slight curve to it. Maybe I'll just stick it in my window and have it display beautiful videos all day long. Or build a flight simulator. Or take it to work to show them what I did with all the monitors I took home(they were going to be eWasted if I didn't adopt them!).

Anyway this should be entertaining.

[Cornucopia]

One thing that you have forgotten since after post #2 is: you will want/need to calibrate your monitors if you mean for them to look like a unified mega-object. This isn't a trivial task, particularly the more monitors you add.

Scott

[pandy]

I'm hoping to find a software solution where I can basically feed a video signal in from a variety of sources and have it show up. But I'm not looking to spend thousands or even hundreds of dollars on this project.

ffmpeg / graphedit perhaps but issue is hardware not software - you need to have HW capable to control 6 displays - go for HW solution - seem you can buy controller bellow 500$

[pandy]

One thing that you have forgotten since after post #2 is: you will want/need to calibrate your monitors if you mean for them to look like a unified mega-object. This isn't a trivial task, particularly the more monitors you add.

Scott

Not so complicated with external camera help - correct pattern and plenty of patience...

[hunterjwizard]

Its not that difficult over all. Calibrating monitors by hand is tedious but not impossible. Since I'll probably need to set this thing up a handful of times with difference sources over the coming years, I won't sweat it too badly.

Seeing some good, handy pieces of software on here, too, to help with the issue.

[hunterjwizard]

So I got my wall mounts today and excitedly settled down to assemble my redneck wall. I took measurements, attached backs to screens, then cut my lumber and was all ready to start bolting mounts on...


[Attachment 27802 - Click to enlarge]

...when I discovered that however designed these bloody things decided they should be just sliiiiiiiightly too big to go on a 2x4. Just in any direction. Won't fit.

[Cornucopia]

You could try bolting pairs of 2x4's together first...

Scott

[hunterjwizard]

I went with 2x6s, plenty big enough. Of course, much like 2x4s they arent ACTUALLY 2x6... but what are you going to do?


[Attachment 28028 - Click to enlarge]

Having some trouble figuring out images on this board, hopefully one of these will work:



Anyway, I cane take more pictures if requested. its a pretty straightforward design, 2 beams along the back, then two supports for the legs. About the most interesting thing to be said for it is the feet, where I got a tad artsy. I'm going to stain the whole thing later.

Anyway, now we move along to the computer-portion of our project, and here is where everything goes off the rails again, haha. So I grabbed one of my computers(one that, like this project, was also assembled out of junk I had lying around) and proceeded to jam 3 more video cards in it(I know its not "best practice", sometimes you have to just follow your heart).

I THOUGHT I had 3x Geforce 440 cards, a dual-head and 2 singles. Couples with the 6800 that powers the machine, that's 6 graphics ports. Loaded up, was surprised to discover that one of the single-head cards was actually an ATI Radeon. I swear, the damn thing looks EXACTLY like a Geforce 4.

So I loaded up drivers, the 4s are getting so out of date that nvidia only has one driver for them, which I installed, along with Catlysis 6.11. For those who've never tried it, you can in fact run ATI cards side-by-side with nVidias(for years, my primary workstation ran on an ATI All-In-Blunder and the aformentioned PCI Geforce 440 with the 2 heads, ran great). What you apparently can't do quite as easily is run 2 difference geforce cards in tandum(he says, while doing exactly that on his main workstation...) When I rebooted, the damn thing blue-screened. Took the cards out one by one until I was down to the pirmary before it loaded with it's own drivers out of wack. After re-loading all the drivers on it, I tried to put the first card back in, and now the machine boots to a black screen, /sigh.

I've got another box waiting for me to drag home from work that I might use instead. I'm also thinking I might run Windows 7 on the new machine vs XP. I know 7s driver support for older stuff isn't great(great being relative as its better than XP in a lot of generations :P) but the way Win 7 with SP1 handles multiple screens is just better. It won't be much of a computer, of course(3ghz CPU with 2 ig of ram if im feeling VERY generous) but it will meet the needs of the project. Those needs mostly being "shenanigans" and problems requiing effort to solve.