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Making A Videowall

Posted by michael on from the one-is-not-enough dept.

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."

12 of 163 comments (clear)

  1. Re:Cropping needs improving by tagevm · · Score: 2, Insightful

    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?

  2. Why? by Anonymous Coward · · Score: 1, Insightful

    It would be cheaper to use a projector.
    And too much space between the screens.

  3. Re:Kinda cool... by handybundler · · Score: 1, Insightful

    That's perfectly justified. When you look at the cost of monitors vs configuration, why not just invest in a projector initially. Considering the nature of an educational use (larger format terrorist training videos? taboo ha-ha) they might be abot to seek sponsorship in this.

    --


    a/s/l here. Sorry, adding domain tags to your s
  4. Re:Wouldn't four quadheads be more usefull by Quixote · · Score: 5, Insightful

    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) ?

  5. Re:Listen to you! by Anonymous Coward · · Score: 1, Insightful

    Dude, welcome to Slashdot. The trolls outnumber the GNU hippies twenty to one. But all that does is prove how superior we hippies are. Jesus, even Taco himself is hell bent on hawking overpiced hardware and modding down anybody who questions the wisdom of $500 gimmicks that will be useless trash a few months down the road.
    Fuck them though. I, like you, appreciate the Pakis efforts. It's the thought that counts.

  6. Re:funny by Anonymous Coward · · Score: 1, Insightful

    what a crap comment! I guess you're only allowed to do hacks if you happen to live in a perfectly functioning society? the other day everyone is says how cool it is that a guy puts a mobo in a pumpkin-- but people shouldn't be messing with a little hack for a video wall in the third world?? WTF?

  7. Cost-effective ? by tmark · · Score: 5, Insightful

    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.

  8. Re:16 monitors vs projector by Ur@eus · · Score: 3, Insightful

    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.

  9. A creative solution to the problem of... by Spurious+Growth · · Score: 4, Insightful

    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

  10. Once again, did anyone read by JWhitlock · · Score: 5, Insightful
    ...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.

    1. Re:Once again, did anyone read by JWhitlock · · Score: 3, Insightful
      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.

  11. Re:funny by dytin · · Score: 2, Insightful

    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.