Simultaneous Capture with many cameras

[cdave]

I need to capture video from many cameras simultaneously. I need to handle up to 32 cameras. I would like to use the pci1411 boards and capture rgb32 ntsc video (30fps). I need to capture about 10 seconds worth of video, storing each image into an array of imaqimages and be able to replay it after (individually). My question is how many boards can I run at the same time on a pci bus, transferring each frame to an imaqimage array? My guess would be 4 capture cards and about 2gb of system memory per computer (8 computers). I figured 1mb per frame, 30 fps, and four cards = 130mb/sec, and 10 seconds worth = 1.3 gigs. Am I on the right track? What kind of computers should I run this on (p4, zeon)? Can I use more capture cards per computer
? Is there a better way to do this?
Thank you
-Dave

[asdf]

Hello Cdave,

You are correct on the 133 MHz bandwidth available from the PCI bus. Each item on the PCI bus will use a portion of the available bandwidth.

Image acquisition requires a large portion of the PCI bandwidth since the data is not compressed (640 pixels x 480 lines * 30 fps * 4 bytes/pixel = 36 MB/s).
- Any other functions on the computer will require PCI bandwidth as well.
- If you are streaming the images to disk, then this will also use PCI bandwidth to access the hard drive.

The application sounds similar to applications regarding security and surveillance. Most surveillance applications use a video multiplexer to combine the video streams. Some of their components are designed to stream video over the network.

Sensormatic (www.sensormatic.c
om) is one company that specializes in security and surveillance.

[BruceAmmons]

Dave,

If you are acquiring 4 640x480 images simultaneously at the rates you mention, you will be tranferring 140 MB/s. This will exceed the limits of the PCI bus even if there is no other traffic on the bus, which is unlikely.

Is there a way you can reduce the amount of data you need to acquire? Does it have to be color? Does it have to be 30 fps? Does it have to be a full 640x480? If you can reduce any of these, it will make your job a lot easier and more cost effective. Otherwise, you will only be able to put two or three cards in each computer.

I don't think the type or speed of the CPU will be a major factor here, unless you are processing the images at some point. If you are just using the computer as a fancy VCR, you just need to worry ab
out PCI bandwidth and memory to store it. You will probably want a SCXI disk drive if you are going to save all these images to disk. A RAID system might be effective also.

Bruce