Separating video streams

Discussion in 'General Electronics Chat' started by SoftwareGuy, Jul 30, 2014.

  1. SoftwareGuy

    Thread Starter New Member

    Oct 29, 2013
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    Is there a cheap and easy (preferably off the shelf or minimal design work) way to convert analog video to digital video and back, for keyed wireless transmission (to keep multiple video streams separate)?

    I'm in the proof of concept phase of a wireless backup camera project and one requirement is that multiple (2 or 3) camera systems next to each other cannot interfere with each other. The cameras are analog, but the only way I can figure to make sure that the picture from system A doesn't show up on the near by screen for system B is to convert the video stream to digital so it can be keyed. Can anyone recommend an inexpensive way to do this?
     
  2. Ramussons

    Active Member

    May 3, 2013
    557
    92
    We need some more clarifications.

    * Are the cameras co-located or distributed?
    * Camera Resolution (no of lines) and Frame Rate.
    * Are all Camera displayed simultaneously on different screens or display is only of a chosen camera?

    Normally, such setps generally involve Digitisation, Multiplexing, and Transmission.
    However, depending on your setup and use, Digitisation and Multiplexing may not be required.

    There are many options with equipment available off the shelf, but we need to study the actual requirement before deciding on a particular stategy.

    Ramesh
     
  3. studiot

    AAC Fanatic!

    Nov 9, 2007
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    Good reply Ramesh!
     
  4. SoftwareGuy

    Thread Starter New Member

    Oct 29, 2013
    29
    1
    Thanks for the reply. It's much simpler than that. Each car will have only 1 backup camera, so 1 video stream per car. However they will be sold to people who will be frequently parking next to each other, so we don't want the video from one car to interfere with the video in another car. That's the only goal; if 2 people are backing up at the same time, video from one car cannot interfere with video from another car.

    As-is the video is analog, 640x480 30fps (NTSC) and we're transmitting it as analog video on 2.4GHz.
     
  5. Ramussons

    Active Member

    May 3, 2013
    557
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    Sorry, but your requirement is not clear. More than One mobile cameras with their own Radio Links. As long as the Frequencies of Transmission in the 2.4 GHz Band are different, there will be no interference - even if the cameras are co-located.

    Or are you talking about Encryption which ensures that a Particular Camera can be Viewed ONLY by a Particular Person? Now that would require Digitisation.

    Ramesh
     
    Last edited: Aug 6, 2014
  6. SoftwareGuy

    Thread Starter New Member

    Oct 29, 2013
    29
    1
    No encryption required, my only requirement is that one video camera system doesn't interfere with another. Think 10 cars in a parking lot, each car has one camera. All 10 cars need to be able to back up at the same time without interference to the other cars. I need to do this in the simplest way possible. If different frequencies inside the 2.4GHz band will do it, then that would be great. How many different bands are available?

    Long story short; these systems will be sold to old people who all frequent the same facility. If one car interferes with another then the old people will likely get confused and might crash into something, so I need to prevent this.
     
  7. Ramussons

    Active Member

    May 3, 2013
    557
    92
    The 2.4 GHz free band is about 80 MHz wide.
    A NTSC monochrome signal without audio would require, typically, 3.6 MHz. There is ample bandwidth for 10 Cameras. But, since you plan to market these devices to the public, there is no guarantee that there would'nt be 2 or more users working on the same frequency - meaning interference and cross viewing.
    The "interference" part has no solution while the cross viewing can be eliminated by digitising and encryption which makes the system expensive.
     
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