Re: multiple webcams via one linux box
Hello Bernie
On 26 Aug 2002 at 9:56, Bernie Berg wrote:
> > I have tested two "Dexxa" webcams (compatible with Logitec Quickcam
> > Express), on the same USB bus. I set it up to take alternating snap
> > shots from each camera. This works well and could be expanded to more
> > camera's.
>
> That should work, but at 85 cams this could get kinda messy. How fast
> can you alternate?
I ran 1 image every 15 seconds per camera, with 2 camera's, which was
enough for my requirement.
There is a very real finite limit to the bandwidth on USB. I don't
think this will scale to 85 cams on one bus. You could try and split
them over say 4 buses and aim for a refresh rate of 1 pic per 5
seconds per camera. It will depend on the resolution of each picture.
> If I used the wireless x10 cams with usb adapters I don't think I would
> reach 15m. The problem I think I would have with the x10's are that one
> receiver controls a number of cams (3 I think) and you can switch
> between them (at least that is how the windows software works), but I
> need them to all act independently. I've tried contacting x10 to ask
> some technical questions but the hold times are too long and they don't
> reply to emails.
I don't see all of those wireless controllers expanding to 85
camera's. (Do they have enough independent channels and enough
range?)
I am going to try "thin client" boxes on a network, each with say 4
cameras - the limitation being the USB cable lengths. 2 Boxes and 8
camera's should meet my requirement. But each box will need power
and a place to live so this probably won't scale to 85 cameras
either.
Your installation will be quite large, have you talked to any
"professional" companies? I would hate to be running around a site
chasing 85 "domestic quality" web cams when one or another of them
keeps dying for unknown reasons and the supplier does not answer the
phone!
Regards
Ian
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Ian Forbes ZSD
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