Whats the current state of outputting real time video data from Jitter?

    Feb 01 2011 | 9:55 am
    Say I wanted a heap of LEDs that could be independently controlled set up as an array...
    Basically a video screen made up of LEDs or similar pitch (3~5mm) light generators.
    What are the different possibilities of controlling them from within Jitter ?
    Video cards pumping out video to stadium/advertising style screens ? Or are there possibilities of something more homebrew ? Arduinos being sent nothing but the essential data?
    What sort of resolutions, frame rates and colour/mono bit depth restrictions are we dealing with ?
    Full LED brightness is near essential as are frame rates above human persistence of vision - we'd like at least 5bit mono colour bit depth per LED per frame... Ideally we're talking thousands of LEDs also, but we're realistic for the time being
    Any help appreciated,

    • Feb 04 2011 | 3:42 am
      no one ?
    • Feb 04 2011 | 6:03 am
      Most large format LED systems have what are called "drivers" that typically read from a specified portion of a DVI or VGA signal.
      Basically, you output video, it does the rest for you.
      Sometimes you have to output video in to specific places in specific sizes. For example, some drivers for an LED screen that might be 320x240 resolution would need you to specifically put a 320x240 video at a specific x and y location within the VGA or DVI output. Those are usually configurable. Some drivers can take the whole full raster video and re-size it and optimize it. It really depends.
      Some LEDS are rarely run full brightness btw, we run the LEDs at the nightclub I work at anywhere from 7 to 16% brightness because, frankly, we arent trying to have aircraft accidentally land on the dance floor.
      For homebrew stuff, you would still probably want something similar, read a VGA or composite video signal in, determine the brightness of the R/G/B channel at a location in the frame that matches where the physical LED you are attempting to address is and then send the command/voltage to the LED. I suspect you will need to run much of this in parallel to keep up. Im sure there are homebrew LED driver projects out there... have you attempted searching?
    • Feb 05 2011 | 2:01 pm
      The other alternative you may come across is DMX controlled LEDs. These can be controlled from Max using imp.dmx and an appropriate dmx interface. Personally I favour using artnet (dmx over ethernet which imp.dmx supports) and Enttec's ODE box. There's an example of this kind of thing here: http://cycling74.com/forums/topic.php?id=27259