Making A Videowall

Ur@eus writes "Zeeshan Ali Khattak has made a videowall using Red Hat Linux, GStreamer and commodity hardware. The solution was made based on the need to create a flexible and cheap solution for use in Pakistani Schools and Universities using commodity hardware. To find out how this was done and some more details, and of course some cool pictures, check out the Video Whale project homepage."

Comments

Cropping needs improving

[fruey]

Great idea, looks good... but in most video walls you have to allow for the space between each monitor when you crop, or reduce the physical space between each. Here, there's way too much space between each screen (both vertically and horizontally) and the images look strange because the cropping doesn't allow for it.

Re:Cropping needs improving

[tagevm]

Exactly my first thought when I saw the pictures. Why don't they just get rid of the monitor cases, so they can put the tubes closer together and make one huge box for the lot?

Re:Cropping needs improving

[helmutjd]

I think in this case they would've been better off with a different brand/type of monitor altogether... those ones have far too much plastic trim around them. Cropping that much out of the movie would really kill the image, and the only other alternative would be to remove all the monitors from their mouldings to get 'em closer together (not fun). Sweet project, though.

Re:Cropping needs improving

[FyRE666]

I suppose a quick fix would be to either physically adjust the monitor controls to make them overscan by a couple of inches in each axis, or set up the X servers to do this. Probably wouldn't help the lifespan of the monitors though I guess...

Re:Cropping needs improving

[moonbender]

It is, if you've already got 20 video cards and monitors ... and that will be true for most schools.

well,

[sirius_bbr]

at least they're showing a good movie on it :))

Why?

[Omkar]

A video wall seems extremely cool but uniquely useless, especially for a school in Pakistan. Can anyone tell me why this wall was built? The only use I can think of is to play Super Smash Bros: Melee. Oh, and the cropping needs work.

Re:Why?

[hovik]

Simulating nuclear explosions. Great way to visualize it, and it's probably a big fad in Pakistan these days.

Re:Why?

[davey_darling]

My first thought was that something like this could be a fairly low buck way to set up a cool video display at a nightclub or party..

You could gather any old mismatched monitors and throw them up on a wall somewhere, hell, even just stack 'em on top of each other and strap 'em together for that cool 'arty' look...

I'm sure there have been many art exhibits that have done similar things before. (you know the ones, they usually highlight the terrible things that television has done to our society and whatnot) Now you can do it too!

Hell, it's a few days late, but I'm sure you could whip up a pretty spooky halloween display with this thing.. Show a creepy movie on displays scattered about the place, instant kinda high-tech terror..

funny

[Anonymous Coward]

starving children aplenty, uneducated masses, and violence over religious differences, and they're messing with redhat to watch The Matrix. Way to utilize those funds!

Re:funny

[gl4ss]

you forgot to mention nuke's.

armament budgets tend to be so big for developing countries that if they could just dump 'em they would be able to feed 'most' of the people.

kewl project though, and totally peaceful.. props for them of that.

Re:funny

[Ouroboro]

starving children aplenty, uneducated masses, and violence over religious differences, and they're messing with redhat to watch The Matrix. Way to utilize those funds!

Well if it bothers you so much why don't you sell your computer, and donate the funds to end world hunger. I see two really good outcomes from this.

1. You get to feel good about doing something to fix the problem, rather than just point at others and asking them why they aren't fixing it.
2. We don't have to read you retarded comments any more.

Re:funny

[dytin]

This is way offtopic, but just to let you know there already is enough money to feed everyone in the world. There is plenty of food to feed everyone. The problem is not a lack of money, it is the systems that are set up in third world countries. When food donations come poring in, the dictators take such a large proportion before it is distributed that the people pretty much don't get any of the original donation. Even if all of the armament budgets in the world were stopped, and all of the money donated to starving poeple, there would still be world hunger, because of the damn dictators.

Wouldn't four quadheads be more usefull

[baschie]

It seems that four computers with four pci videocards would cost about the same as one computer with 4 Matrox G200 MMS Quadhead videocards ($699). You would not need all kinds of software distributing the videosource over four computers and it would make administrating and moving the whole system much easier.

Re:Wouldn't four quadheads be more usefull

[Quixote]

But what about the bandwidth issues? Will the PCI bus handle 16 video streams flowing through it (e.g. a movie, as the wall in the article shows) ?

Re:Wouldn't four quadheads be more usefull

[ottffssent]

Well, why don't you think about it a little bit first? You've got about 100MB/sec (800Mb/sec) available for the cards. Divide by 2 bits per pixel gives 400Mpixels. Divide by 16 monitors and you've got 5Mpixels per monitor. Even at a resolution of 2048x1536, that's only 3 Mpixels per monitor. Repeating our calculation at 32 bits per pixel, we get 200Mpixels, or 2.5M per monitor, about 1800x1440 resolution.

So yes, there is plenty of bandwidth.

16 monitors vs projector

[Anonymous Coward]

Hmmm. 16 x 17" monitors @ $200.00 each is $3200.00... Hell, even if they were only $100.00 each you can get a very nice projector for less which will blow away the functionality of this system.

The whole idea behind a video wall is that you can display the same, different, or transitional information across the monitors. They (the monitors) can be ganged together for a single display, split into sub-displays, or data can be moving across them. The system that they describe has very limited use and will not be able to do what a videowall is meant to do.

Videowalls are quickly being killed these days by projectors except in the instance where you have limited installation depth and do not have room for the minimum throw of the projector. Or I guess where the ambient light is too high but even then you would want non-glare screens on your video wall for the same reason and the lamps in projectors are getting quite bright these days.

Even if you take into account the annual cost of lamps for the projectors you would have to balance this out against the maintentance cost in parts and man hours of the system he has built. bet it works out pretty close.. Just getting all 16 monitors to calibrate equally is going to be a nightmare.

Re:16 monitors vs projector

[FyRE666]

Ok, what if they used a cluster of 16 projectors? ;-)

Re:16 monitors vs projector

[Ur@eus]

Actually part of the plan as I understood it is actually just to use the normal computers of the school computer lab and just quickly assemble the videowall from those when needed.

Re:16 monitors vs projector

[pridkett]

Oh you mean something like this. As they'll tell you, it's not as easy as you think. Most commercial projects don't color balance with each other all that well because well, they don't need to. Plus there is need to do some funky stuff with fading around the edges. ANL also has a MicroMural and MicroMural2. The MicroMural2 is pretty impressive to see a full screen hi-res video running on. They've done a good job of making the projecters blend together.

The other issue is the noise and heat that LCD projectors make. Which is pretty significant.

Re:16 monitors vs projector

[Jeff DeMaagd]

$15,000 USD is probably for a home theater projector or a very bright, very high resolution presentation projector.

Also, local supplies can't compare to the variety available on the internet.

I bought a 1300 lumen XGA projector, built by NEC, for $2300, and the colors are pretty nice. Granted, it was refurbished, but competing units new aren't too much more, Panasonic has one available for $2500 at some sellers, it lists for $4000. These aren't one of those cheesy overhead panels either.

The CDW unit you linked to is 7700 lumens, which is _very_ bright, for a lot of uses, 2000 is plenty. I thnk that Sanyo can be had quite a bit cheaper elsewhere, CDW tends to be pretty expensive.

While projects enhancing the flexibility of open source should be encouraged, I wouldn't expect that anyone would really want to use this to watch movies.

Re:16 monitors vs projector

[Jeff DeMaagd]

I forgot to point out that I do understand that Pakistan is quite a bit of a different country, pricing and availability is vastly different. The previous post was pointing out that you can too get a _good_ presentation projector for much less than what was linked to.

I wish I knew how to get older computer hardware to less wealthy and even impovershed countries that could use them, I think I might even have a spare video card of what they are using.

They need an S3 card eh?

[Provocateur]

I'll trade you one S3 card for 4 of those monitors :-) Yessirree these cards are expensive here heh heh

simulated

[SubtleNuance]

For god sakes man

take those monitors out

of their cases. Put

Them closer together and

kill the funky spacing.

movie.* = comedy

[bumby]

Any movie watched on that wall will make it a funny
comedy. I mean, just watch the head on this dude!
http://www.gstreamer.net/apps/vw/vw_files/p ic07.jp g

"...When the aliens invaded!!"

Re:movie.* = comedy

[SCHecklerX]

Any movie watched on that wall will make it a funny comedy. I mean, just watch the head on this dude!

So, basically it turns all actors into canadians.

"What's wrong with their heads?? It's ok, their canadian." (or something like that :)

Re:movie.* = comedy

[enneff]

Err, speaking from an outsider's perspective, Americans and Canadians look almost exactly the same.

Re:movie.* = comedy

[ncc74656]

Err, speaking from an outsider's perspective, Americans and Canadians look almost exactly the same.

You've never watched South Park, have you?

Listen to you!

[Matey-O]

Jeebus Cripes! These guys whip up a Cool Hack(tm) with scrounged materials, make it work and add to the collective abilities of Gstreamer and all you have to say is 'it looks crappy'.

What a bunch of hypocrites. The fact that the monitors can be swapped out after a proof of concept, and that you've got the power of four CPU's available (Beo-mumble) is completely lost on you guys.

And I've figured there'd be at least ONE MPAA crack from somebody.

Re:Listen to you!

[lucifuge31337]

I would have been much more impressed if it were scrounged hardware. The monitors are new...not the plastic on the display cable of most of them still. All in all, if looks like crap, and the cost of parts exceeds a better alternative. I call that a bad idea.

Re:Listen to you!

[Pfhor]

Actually, not everyone removes the plastic wrappers that come with new stuff. I have a friend from india who has had a vcr for over 2 years now, and the remote is still in the protective plastic wrapper.

Re:Listen to you!

[Pfhor]

Well, i actually talked to him about it, and he mentioned that its really common in india. To the point where if it isn't really getting in the way, why bother taking it off (such as leaving the plastic on the monitor cables).

Cost-effective ?

[tmark]

the need to create a flexible and cheap solution for use in Pakistani Schools and Universities using commodity hardware

I just can't believe this is cost-effective for more than a 4-screen display. With quality video projectors costing less than $2-3000 USD, this solution doesn't save much money, and is far less convenient in terms of portability - how would you even move around an 8x8 grid of monitors -, which would seem to be key for application in schools and universities. Also, the whole array is visually distracting due to the breaks between the monitors.

Sometimes people get distracted by technology and forget about the constraints of the problem to be solved.

Re:Why not use old LCDs?

[kubla2000]

You could salvage LCDs from old laptops.

Not so easily done: http://www.eio.com/lcdconnect.htm as far as I can tell, you'd have to get into some pretty heavy-duty electronics and buy convertor cards to handle the different input expected by a laptop display from that which is delivered by a vga card.

@#$@ the warl

[Nobley]

Wire this thing poorly and you might just get yourself a Firewall.

Re:Why not use old LCDs?

[Bobartig]

..And it would costs abouts $200 a pop to get converter boards to use those LCD monitors on a desktop display. A lot of people assume that it's economically advantageous to use laptop LCD's instead of desktop ones. Typically, it doesn't cost less to use a laptop screen with a desktop, and the only places it makes sense is when you very specifically need like a 12.1" or 8.4" screen in a dash board or control panel. This thread talks about the technical problems associated with laptop screens on the desktop, and these guys carry everything you need to do it. Check it out, it's really expensive, even if you have 16 laptops with identical LCD's.

eliminating the spaces...

[rusty0101]

I have seen several notes deriding the spaces between the displays. The "fixes" suggested for this include using LCDs (which I suspect are outside of the budget), or disassembling the monitors and bringing the CRTs closer together. (anyone want to discuss the safty issues of pulling one of the center displays out to replace it?)

I suspect it would be far cheaper, to use fresnel lenses in front of the CRT's with modifications to the rack they built to center the CRT on the fresnel, and mask off the power light for the monitor.

Will it be perfect? No, but I think it will be more flexiable.

-Rusty

Re:eliminating the spaces...

[Bobartig]

wouldn't using all those fresnel's kill your viewing angle? I don't think you could view it in a classroom setup, unless given a really long room.

There are those projector hacks where people attach a hood to their tv/monitor, then pass it through a fresnel and onto a surface. If you built 16 mini fresnel rear projectors, I think you'd end up with something like the setup they use in bestbuy, which is like a bunch of rear projection TV's.

Couple of things...

[Junta]

1) Why did they need a videowall in the first place? What is the point?

2) Why use a video wall, when a Projector would be much more clean and efficient? Even if the ambient light was high or the didn't want people blocking the path, they could rig things so the projector is behind the screen in a dark room. Lack of throw area can be compensated for through use of mirrors to reflect the path....

More complex utilization?

[Fastolfe]

It's kind of nifty that any Joe can do this, but one of the things I see these types of video walls being able to do is to change the arrangement and utilization of the 16 monitors, so that one second you might have a 4x4 video stream, and the next you might have a 2x2 stream in the center with some other type of content elsewhere, or a 3x4 stream with 4 1x1 screens of other information, that sort of thing. If there was an easy way to define these types of "programs", independently of the video stream(s), that might make these things a little more fun to play with.

You've got to be kidding!

[flikx]

This is for Pakistani schools?? What a crock. Meanwhile, American schools are using old 15" televisions from the 1970's in stuffy classrooms filled with 45 children. If the school even has a television or two to share with all classrooms in the entire school.

A creative solution to the problem of...

[Spurious Growth]

No Funding! I think the point that people are missing here is that the project does not have a budget. There is no money to spend on a video projector. The entire system relies on hardware which is, on a regular basis, serving an entirely different purpose. This solution allows them to create a large display when it is necessary, out of components at hand. Almost any computer lab can generate a 4' x 5' display on demand.

Also, what is the effective resolution of such a screen? It sounds remarkably similar to the IBM ultra high resolution LCD we heard about a while back.

Spurious

Once again, did anyone read

[JWhitlock]

...or just look at the pictures. As the author states:

I rather quick realized that the only extra component we needed in Gstreamer was one that that did the cropping for us. At the same time I also saw that my knowledge about multimedia and GStreamer was not good enough to allow me to write this element. So I tried asking my friend Wim Taymans if he would be willing to take on the task of writing such a plugin. He was kind enough to do that not only because of my need, but also because he saw it as another nice feature of Gstreamer that would be needed by many others.

So, they know that cropping is a problem. But that's just software (and maybe a bit of hardware, with those huge borders). But that isn't their biggest hardware problem.

It turned out however that our biggest problem was finding PCI video cards in Pakistan whose XFree86 drivers could do XVideo, this in a situation when its hard to even find PCI video cards at all in the market. Solving this problem of lacking parts took us 3 months and at one point we even considered abondoning the project. We still need more cards because we do not have more than these 16 s3virge/DX cards. If any of the cards stop functioning, we are out of business.

This isn't the U.S. - it's Pakistan. They can't go to eBay and find a 4-head card, or even pick and chose cards (or even monitors) based on requirements. They have to use what they can find, and I for one am impressed. How many of you would give up if it took three months to just find the hardware?

This is a great engineering story, of folks working with what they have, and a great Free Software story - they could have tried some pirated copy of commerical software, but instead they decided to use open source components, stretching what is possible. Could it have been done with a projector? Sure, if one was availible. But now the state of multi-monitor free software has been advanced a little, which may benefit you or me some day.

I hope that there were some other people who saw how cool this was, who are contacting the authors with useful suggestions about removing the shells and mounting the tubes closer together, that are looking at the GStreamer source and thinking about how to add cropping, and how to make cropping easy, and hopefully a few people that are thinking about donating equipment, and realizing how lucky they are to live in a world where you can order a projector from Amazon and have it delivered in days.

Re:Once again, did anyone read

[JWhitlock]

and realizing how lucky they are to live in a world where you can order a projector from Amazon and have it delivered in days.

Maybe we aren't lucky for it, maybe it makes us lazy?

Nietzsche is alive and posting on Slashdot?

It may make us lazier in some ways, but allows us to do more in others. I would never create a project like this - I'd just buy a projector. That may make me lazy, but it means I can invest my time and energy in the presentations I put on the display. Sure, technology and privilege makes it easier to be lazy, but it doesn't require us to be lazy. It allows us to use the same amount of energy but get much more done.

This reminds me of my earliest programming days, when I was inspired to learn programming by Mandelbrot and Julia sets, and movies like TRON (not the fantasy of living programs, but the cool 3D graphics that looked possible to duplicate). It was a difficult journey - it took a long time to find a language that was fast enough (BASIC was a little slow), and that had reasonable graphics libraries (MODULA-2 didn't). I taught myself C and C++, coded a basic driver for my graphics card, and learned matrix transforms to draw 3D graphics out of line and pixel primitives. I didn't get far - the best I did was implementing a 3D scene generator out of a book.

Today, I'd download the ActiveX libraries, or OpenGL libraries, and use gcc or Java or something else to draw my objects. I'd never have to learn how to interact with the video driver. I could be creating Quake maps without knowing how to do a matrix operation or a binary tree representation of a scene (which I never learned).

Does that mean I'd be lazier if I was born 10 years later? Nope. I'd just be able to quickly jump the hurdle of low-level details and concentrate on the higher level stuff. Maybe I'd study art more, to learn what makes a good 3D scene. Maybe I'd study basic AI, to make my creations more life-like. Or maybe I'd still learn all the way down to register instructions, because I like to see how far down I can go, but I'd have better guides down known paths (like Michael Abrash's Graphics Programming Black Book.

Remember, without this crazy, materialistic, wasteful country, no one would have developed cheap graphics cards that make their way to Pakistan in the first place. Keep ignoring the modern miracles of reliable computer networks, always-on electrical grids, indoor air conditioning, and market economies. Continue to prosper without guilt. But do try to leave something useful for those that come after you.

There is another good use...

[gozar]

Yes, for this particular application I feel that a projector would be better utilized, but there is another cool way this could be used. By using just two screens you could watch a letterbox movie! That is something you could try at home, with just two video cards. Get a couple of 19" monitors, remove the cases, put them close together, and viola, your own wide screen high resolution monitor...

Wouldn't a LDP proyector be a better choice here?

[eyefish]

I don't want to take credit away from this proyect (I already have it archived into my "cool video hacks" category), but I think in this particular case it would be cheaper, simpler, faster to setup, smaller, and more convenient to simply use a DLP-based video proyector with a high lumens value (plus you could get a much larger image with better image quality as freebies).

If you notice, the Vide Whale is only about 6 feet high, and it suffers from a software problem which is basically not cropping the areas between the monitors (makes it look pretty bad). So, why not the DLP solution? I'm pretty sure they can get something decent for about 3,000 dollars, which I bet is way cheaper than the price of all the machines, video cards, monitors, and cables combined (not to mention the time saved when setting it up and the costs saved in transportation).

what a shitty way to watch the Matrix...

[scharkalvin]

If you want to make a huge screen out of many smaller ones take the tubes out of the cabinets and get them closer together or find monitors with smaller bezels. I think they make monitors designed for those video walls in mind. Hate to say it but the picture sucks!

OTHO for the right application, it is a clever hack.

Ahh the Matrix on a matrix of monitors...

[wiresquire]

As you can see, we've had our eye on you for some time now, Mr. Khattak. It seems that you've been living two lives. In one life, you're Zeeshan Ali Khattak, program writer for a respectable software company, you have a social security number, you pay your taxes, and you help your landlady carry out her garbage. The other life is lived in computers, where you go by the hacker alias Zak147 and are guilty of virtually every computer crime we have a law for.

One of these lives has a future, and one of them does not. I'm going to be as forthcoming as I can be, Mr. Anderson. You're here because we need your help.

We know that you've been contacted by a certain individual, a man who calls himself umer_pk. Now whatever you think you know about this man is irrelevant. He is considered by many authorities to be the most dangerous man alive. My colleagues believe that I am wasting my time with you but I believe that you wish to do the right thing. We're willing to wipe the slate clean, give you a fresh start and all that we're asking in return is THAT YOU CLEAN THIS FRIGGIN MESS UP AND BUY A BIG SCREEN TV!

Ideal videowall

[Gerry Gleason]

I've had this idea of a while that you could "tile" a large flat screen monitor from standard low res flat panels. With existing tech, you could do way better than this project by finding the cheapest low res LCD monitors, and either find a model with narrow edge trim, or remount the screens to get minimal spacing. Of course, this is lame if the screens aren't cheap enough, and who really wants a big screen with visible lines between tiles. What I wonder is, whether it is possible to design a module and mounting method that eliminates the lines completely. Maybe have modules that butt right up to each other (maybe even connect together, but I digress), and then have a single piece glass in front, possibly with a difusion surface to help merge the pixels. For big screens, even with high res, the actual pixels could be pretty big, so you could have 1'x1' module with say a 20 dot per inch pitch for 240x240 pixels.

Ok, maybe twice that resolution for an HDTV resolution in smaller sizes, but this would be good for say on 8x12 screen. They would have to be $10-50 per tile to be really worthwhile, but even a bit more than this would be competetive with current large flat panels, but you need to get down to the lower end of this to make it really popular. The big if would be whether it looks just as good as a one-piece design.

Damn cable bags

[skinfitz]

Looks like they cant get those silly plastic bags off monitor cables in pakistan either.

Anywhere you want to show off tech ability?

[fantomas]

I dunno, how about anywhere you might want to do a bit of high tech / glam PR ...industry conventions, sales shows, University open days, art galleries - hey, the kind of places people hire this kit for in Europe or USA.... What a thought.

I agree it seems a bit of overkill for a school, but why not the above reasons?

.

As for why do it, do you really think justification is required for a tech project on /. ? Seems a damn sight better use of tech than stuffing a computer into a rotting vegetable (halloween jack-o-computer). This guy might get a bit of a business out of it as well.

Just imagine ...

[LoudMusic]

a ... BEOWULF cluster of THESE!!! ... yeah.

Over complicating the problem

[Catskul]

You can leave the laptop lcd's still attached to the laptops and allow the laptops to control the screen. You can get decent enough laptops on ebay for less than the cost of a new video card and monitor.

More importantly, what will they call it?

[commodoresloat]

What are they going to call a wall from the video whale project -- the Whaling Wall?

Props from the USA

[MsGeek]

Very impressive. All you schmucks who are drooling on and on with your anti-Islam, anti-Pakistani statements are really pissing me off. These guys basically took monitors and video cards that would normally be consigned to dumpsters here and turning them into a pretty amazing video wall. So, they have yet to put the guts of the monitors into cases that would allow closer placement of the CRTs. Big whoop. That's just a matter of time and materials. Any idiot can physically mod a case, be it a PC case or a CRT case.

Props for a very cool experiment, guys. Don't let the trolls grind you down.

Zeeshan Ali replies:

[Zeenix]

Hello, Let me answer all the queries in one reply cause i see a lot queries asking the same questions again and again.

(1) About the Need for schools/universities: Well, its quite obvius that the price of our video-wall is not less than the commercially available projectors. but for that possibility every school/college shall HAVE to buy a projector of course. But many of the schools/universities have a lab of atleast 16 computers networked together. So we can arrange them such a configuration that will allow them to make a video-wall within some minutes when ever they need to.

(2) About the cropping: Oh we only needed to change 4 config files for that and we fix this one a day after we took the pictures.

(3) About taking the gap out: we've thought much on that matter, like taking out the monitors out of their cases. we tried all that but that didnt matter at all. And if you look at the screen from the distance its intended to be kept from the audience, the effect of those gaps reduces significantly. Trust me on this :)

(4) About terrorism: well, i can only say that being a member of an open-source community, i know the value of Freedom...

Are things cheaper in Pakistan?

[JWhitlock]

It is far easier and cheaper to get any software and hardware in Pakistan! As you already know there are no strict laws on piracy so everything is dirt cheap. Also the second monitors should not be more than 30-40 USD per piece. But the point remains the guys did a nice job and put together a nice system.

Is this correct? Are you from Pakistan?

I tried to see if I could get a package to Pakistan. With a bit of research, I found a page for the North West Frontier Province Primary Education Project (NWFP-PEP), based in Peshawar, Pakistan. However, that website does not have a postal code as required by UPS. Is this a sign that they don't make regular deliveries there? FedEx did not require a postal code, and they claimed they could get a 4ftx4ftx4ft, 50lb box to Peshawar for only $316.43.

So, hardware from the U.S. may be a little expensive. But you think that the Pakistan hardware market would be cheaper?

Now, I imagine software piracy is pretty widespread - Microsoft Windows and Office are probably availible for the cost of a CD, and a Matrix DVD made it's way to Pakistan. But multi-monitor video is a pretty narrow application, usually provided by the vendor of a multi-head graphics card. It would probably be eaiser to get Linux tools to do the job than to try to get a pirated copy. Plus, I'm not sure what their internet connectivity is - they seem to have the basics (a yahoo email account), but I'd expect at least one of the people to have a University email account. The website is hosted on the gstreamer website, not in Pakistan.

Please enlighten me how they would get the needed software and extra montors for $30-40 USD each.