I really should write a Wiki article about this since it comes up frequently.

There are many many multi-camera cards available and they fall into two distinct classes:

1) Cards with 4 analog video inputs but only one video processing chip. These typically sell for <= US$100 and are common on eBay and such. They claim to support 4 cameras simultaneously but when you really dig into the "fine print" you will see that unless you use only THEIR application software the card actually only supports one cam at a time. Four can be plugged in, but the card appears to Windows as a SINGLE capture device with the capability to switch between 4 sources. Think of it as being like a TV card - a TV card can receive hundreds of channels but you can't watch them all at once. Likewise for this type of capture card - it can marshall 4 signals but only pass one at a time to applications. (If you use their app software it simulates 4 simultaneous video streams by rapidly switching the signal selector logic ahead of the vid processor between the inputs and sorting it out in software - yuck). This type of card WILL NOT capture more than one cam at a time when used with AbelCam (or any other 3rd party app).

2) Cards with 4 analog video inputs and FOUR video processing chips (1 for every input). These typically sell for >= US$200 and are a bit harder to find than the cheap cards. They're considered high-end gear apparently. This sort of card appears to Windows as FOUR capture devices. Thus four cams can be used simultaneously by AbelCam or, for that matter, 2 by AbelCam, 1 by a video conferencing program and 1 by an instant message program... or whatever. The point being that they present the cams to Windows as 4 distinct "things" that can be used at will by various programs. Obviously this is the type of card you need to get if you wish to add 4 analog cams to an AbelCam setup.


Afterthought: some of the "Type 1" cards' drivers expose their input-switching capabilities thru their APIs. AbelCam already knows how to interact with certain standard switching APIs. For example, I have a super cheap Conexant-based TV/VidCap combo-card, and AbelCam supports switching between TV, NTSC capture, and S-Video. So, if you had 4 cams but never need to watch (or detect motion on, or record) more than one at a time, a cheap card plus AbelCam's switching support might work. Before buying into this idea, consider that more than one person may be viewing your site at the same time. Since the input switching happens in the hardware, if User A switched inputs, User B's video feed would also switch. Probably not a good thing

I can not guarantee that any specific card will work because I have not personally tested any of them. The final decision is up to you, but from looking at specifications and having a decent understanding of how AbelCam works internally, I think this device looks like it should work:

http://www.euresys.com/Products/picolo/PicoloTetra.asp

They cost about US$650!

Just remember when looking at capture cards that you want one that processes 4 cameras "in parallel" (or "concurrently" or "simultaneously") and NOT one that uses "switching" (or "multiplexing").

Sorry I can't be more specific. But I will not tell anyone they should buy such expensive hardware unless I have tested it myself.

Consider this: if you have enough open slots in your computer it may actually be cheaper to install several of the cheap (US$50 or so on eBay) "switching" cards - 1 for each camera - and only use 1 input on each card. I have actually done this before: I have two cheap TV/capture cards (different brands, but both based on Conexant 878 chips) in my server right now, they show up in AbelCam as "Conexant Video Capture-1" and "Conexant Video Capture-2", and they work fine together.