Multiple webcams

[sooim3]

Hello,

I'm not sure where this topic should be posted, but I hope it fits here...

I have been browsing around the Internet for information about using multiple webcams connected to a single computer (I'm interested in webcams for PCs). My problem is that, after a week of searching through the Internet, I haven't found anything that could really answer that question (and sales people at computer stores, including sales support at Logitech, haven't been able to provide me with any solid answer either). What I want is to use three webcams and process those images that come from all these webcams at once (i.e. within an application/software).

Does anyone know if it is possible to connect multiple webcams to a single PC? Has anyone connected and used more than one webcam with the same computer? If it is possible, does anyone know if the same webcam software (or other compatible software) can be used for all webcams involved, or if separate software is needed for each webcam? Or can anyone point me in the direction where I could find more information about this?

I am looking for an answer to these questions mostly because I don't want to go and buy extra webcams if it isn't possible to use multiple webcams in the way I would like to use them.

/Soo-Im

[cscgal]

Yes, it is possible to connect multiple webcams to a single computer and have the computer detect and receive feed from all of them. No, I am not sure if it is possible to simultaneously receive feed from all of them.

[sooim3]

Thank you for your response and information.

/Soo-Im

[whipaway]

I would think that each webcam would have to be from a different mfr., otherwise how do you tell one from another?

[cscgal]

Each piece of hardware has a unique serial number that allows the computer to recognize it, even if its the same product from the same manufacturer. Take, for example, a computer lab of networked computers hooked up to three identical laser printers. Each computer on the network can print to any of the printers hooked up to the network. This is actually a common occurrence in computer labs, small office networks, etc.

[whipaway]

So you're saying each webcam has its own embedded serial number?
Possibly this info can be transmitted over the internet, and this would raise some privacy issues in much the same way the Pentium serial number scandal did.

[cscgal]

I'm saying that usually hardware has some unique identifier - whether a serial number or what not - that allows an operating system to distinguish it.

For example, this is how the Microsoft WindowsXP activation works to disable pirating and warez. Your operating system takes a snapshot, so to say, of the unique identification of all your hardware, and then sends that information to Microsoft when you register your operating system.

You can have two exact duplicate systems - same exact hardware, manufactuer, etc. etc. but Microsoft still knows it's two different computers due to their individual hardware identifiers ... which is basically just Microsoft data mining.

Microsoft allows you to change three pieces of hardware in your system before it considers it pirating. In fact, Microsoft knows what hardware you have and what you change/upgrade/etc.

But of course they're not doing anything morally wrong. Oh, no, of course not ... ;)

[cscgal]

Ammendum ... that's why manufactuers have to buy multiple copies of Windows for each computer they manufactuer. The same copy of Windows won't install on multiple machines, even if they're the exact same hardware! The hardware's unique identifiers prohibit that.

[whipaway]

Microsoft WindowsXP activation? I'm sorry, I don't know anything about that. :-)

[whipaway]

This tread is quite timely because I am currently evaluating some 'el cheapo' webcams. I will try to get another one of the same model as one of the ones that I already have, and will see if two of the same model can be easily distinguisehed by various webcam software.

[cscgal]

Microsoft WindowsXP activation is Microsoft's way of making sure that their software is only installed on one computer and only one computer. It forces you to activate (or register) your software once it was installed, at which time it sends information about your hardware profile to Microsoft.

If you try installing it on a second machine, when it asks you to activate, it calls up Microsoft and checks to see if the hardware profiles match. Because all hardware is unique, even if it's a duplicate of the exact same hardware, etc. the hardware profiles won't match.

[whipaway]

Microsoft WindowsXP activation is Microsoft's way of making sure that their software is only installed on one computer and only one computer. It forces you to activate (or register) your software once it was installed, at which time it sends information about your hardware profile to Microsoft.

Maybe your version forces you to do things you don't really want to do, but my version didn't ask for, or force me to do anything, or even go online.
PS: I have about 6 PCs with this XP on it no problem.

[cscgal]

Warez or pirated versions of WindowsXP have been hacked to remove this activation feature. In addition, if you buy your computer pre-built from a manufacturer (e.g. your laptop), to the best of my knowledge, they come pre-activated by the manufacturer.

[whipaway]

This is an Enteprise edition of XP, so there is no restriction on the # of installs.
CSCGAL, you know I don't use and warez or pirated softare! :-)

[cscgal]

Oh, yes, of course not.

[unb0und]

i recently had an encounter with the max. number of installs with activating WinXP Home. kinda freaked me out cuz i didnt know what was going on :D

[flyashi]

OK i've been trying to do this for some time now and here's what I've seen.

There are some pages (some astronomy site where the guy used two cameras on two telescopes to get pix of stars, some security software websites, etc.) that definitively claim that it is possible. there are others that claim that it is definitively impossible. Well, it is possible. If i figure out how to upload pix, I'll show u. It does work.

HOWEVER!!! there are a few issues. I'm assuming you're using USB webcams cuz firewire there's no problem with whatsoever. Also any CCD cameras (logitech quickcam 4000, etc.) which usually cost $100+ have no problems. Most cheap webcams are CMOS. What I have gotten to work is a logitech quickcam express that came free with my computer and a $10 no-name one. I had to play around with the connections...cuz they take a significant portion of the USB bandwidth, so I had to connect them to separate USB root hubs. After a bit of playing around with the software (i had to open the program, open it again and select the second camera, then close the first one and open it again) but it would eventually work on low resolution.

My current task is to get two identical cameras working. They're showing up as separate devices 'cuz theyre on separate root hubs, but when I load the porgram, it shows that there's only one camera driver. That's because both use the default WDM (windows device manager) video drivers. That can only do one cam at a time. Repsectable manufacturers (kodak, sony, logitech) will write their own drivers instead of relying on microsoft's. That's why one camera using microsoft's and one using logitech's worked. Two identical no-name cameras is not looking good, but i'm not giving up! If i get more, I'll post it. Meanwhile, if anyone more experienced can help me out in hooking up two webcams to one computer, then I'd gladly take the help!

Thank you, good luck, and godspeed.

- me

[cameraeye]

My current task is to get two identical cameras working. They're showing up as separate devices 'cuz theyre on separate root hubs, but when I load the porgram, it shows that there's only one camera driver. That's because both use the default WDM (windows device manager) video drivers. That can only do one cam at a time. ... Two identical no-name cameras is not looking good, but i'm not giving up!

I am also trying to control two cheap WDM USB cameras with a single computer. I, also, can't get the software to distinguish between the two. I am trying to use RealProducer's RMBATCH utility to record from either of two EZCam III cameras (I never need to record from both simultaneously.). Sometimes it will pop up a dialog box letting me choose between two identical cameras listed in a drop-down list (entirely missing the point of the autonomous "batch" idea), but usually it just grabs the first.

If anyone has had any success, I'd love to hear your story.

no, I'm not trying to do astronomy . . . --mark

[flyashi]

If you never need more than one at a time, that GREATLY simplifies the problem to merely switching between the two sources.

I'm not an expert in the API call, but looking at the declarations, when you open the driver (in VB, at least), there's paramaters for which driver and which input source you want to use. I know there are separate commands for launching the window; worst comes to worst, you can simulate the keystrokes necessary to switch between the cameras. But by playing around with the parameters, you should be able to select source 1 instead of source 0.

I've never used the RMBATCH, but if you look at their documentation, somewhere in there should be "Source Selection", or the like: For example, well this is a bad example, but anyway: Suppose you have a video capture card with four video inputs: You have to somehow select which input you want to use. Although this is "channel" selection and not "source" selection, the idea is the same, and the code to do this should be documented in the utility's support area.

Well, good luck to all. If I ever get this working well, i'll let y'all know.

- me

[mel73]

Hi!

I have the same problem. I need to have two webcam on the same computer because I want to take two picture in the same time, so if I can just clik one time or press enter to snap the two picture.
but, even if I have no cheap webcam (100$CAN one), I don't succeed to have the both on the same. I use window 2000. could you help me?

thanks

PS:I already try to start two times the software.