Ask Slashdot: Multiple Webcams and FreeBSD

Swamp|Fox asks: "I've been tasked with finding a way to have multiple web cameras (at least 6) capturing simultaneously for a soon-to-be-opened daycare. This is not exactly a new idea, and there are many daycares out there utilizing it. The idea is that parents can check in on their kid(s) from their office. There are many commercial packages out there, but none that quite fit perfectly. The problem(s) lie in the fact that there will be a singleserver, most likely a PentiumII 300, with 256 megs of RAM, and U2W SCSI, acting as both the web server, a NAT'd internet gateway/firewall, and the capture host for the webcams." There's a bit more to this, but the gist of it is that this fellow is looking for options. Click below for more.

Swamp|Fox continues...

"The webcams will be located between 25' and 50' from the server, and should support capture sizes up to 640x480. Another item, which I'm not too hopeful can be filled, is that the still images can be taken every second, or even 3 seconds, so that the director of the daycare can view them in near-realtime, while a script runs in the background and grabs every 15th frame for display on the web. The best solution I've found so far is WinCam.Live from Stardot Technologies, and it seems to fit most of my specifications. The big problem was that its cameras can only capture a frame every 15 seconds, but in retrospect, that is probably a limitation of serial port based webcams (which are the only way i've found to get webcams that distance from the server). They even offer a UNIX capture host, currently tested on Linux, and Solaris (my local *BSD techhead is working on fixing the makefile to compile under FreeBSD).

I'm looking for feedback, either on this setup, other experiences UNIX sys admins have had (both with this system, and multiple webcams in general) as well as other alternatives I might want to investigate. As usual, Open Source Software was chosen to keep the costs down, and for the flexibility to perform multiple tasks on a single server."

Comments

Possible Option

[Anonymous Coward]

See "Nuts & Volts" magazine, May 1999 (Vol. 20, No. 5) They demonstrate a simple RS-232-controlled video switcher for up to 16 sources. This is combined with a video capture card and some basic software (Win98-based in this case, but could easily be adapted to anything) to switch among the video sources and capture frames. With only 6 of the inputs used, the frame-per-second rate desired should easily be attainable.

I've got a spare copy of that particular issue. I could mail the article (address?) or perhaps scan it or something, if it might be of any use.

The switcher is available from the author in both kit and pre-built forms from http://members.aol.com/ncdcat/. Select the "A/V Switching" link.

Hope that helps.

qcwebcam

[Alex Belits]

It takes about up to 1 fps at 320x240, 24-bit color or up to 4 fps 6-bit B&W of the same size, has parallel interface (I was able to use up to 3 per box with additional parallel interfaces on the card), and it works with Linux and FreeBSD. See http://www.fhttpd.org/pub/qcwebcam/R EADME.html, http://phobos.illtel.denv er.co.us/~abelits/apartment.php3 for an example and http://phobos.illtel.denver.co.us/qca m-config for controls page.

It's possible to modify the code to increase the resolution, however this kind of camera has twice higher resolution for green component than for red and blue ones, so even though picture will be 640x480 it won't be the same thing as real 640x480.

Axis camera server can be used

[nneul]

It allows hooking up 4 B&W or Color coax cameras and 1 SVideo camera, completely self contained.

We use it in conjunction with a linux based server that grabs the images off the camera server every few seconds.

Biggest problem I've had is that I would like to dynamically assemble the images (can be retrieved either as gif or jpg in many sizes) into a video stream (bandwidth is not generally an object, but gif anims are way too big).

Use the Axis camera instead of Stardot

[Hanno]

Hi,


others already recommended the Axis camera - I agree. :-)

I have been doing a lot with webcams for the company I worked for in the past, even made a review of different webcams for a German internet magazine. That hardware test was about a 1.5 years ago, so my experience is a bit dated.

To sum up: The Axis camera was the best of the crowd. It is basically a camera with an ethernet plug. _Great_ image quality, very easy to use in a network. A bit pricy, but definitely worth it. (http://www.axis.com/products/camera_servers/)

The Stardot camera has a few nice benefits, too. It uses a standard serial connector, you can use customized cables that are _very_ long, you can also use it with a modem. But the image quality of the camera that I tested 1.5 years ago was just _lousy_. It was even worse than the first version of the Connectix colour quickcam.

The old parallel Connectix camera has a lot of support by different Unix flavours, yet I only had running three of them simultaniously on one PC. Also, the quickcam really hogs any computer because it needs to be polled all the time - stupid protocol chosen by the developers.

Microplex offers a camera hub made for the parallel quickcam (http://www.microplex.com/microplex/info/networkEy e.html). But since the parallel quickcam is hard to get these days, it is probably not an option for you. Also, the Microplex hub was nice and a good value for its price, but only if you already own a quickcam.

There are a lot of USB cameras out there (the Philips product is _really_ good), but there still is no support that I know of for Linux. Don't know about BSD though.


So to sum up, the Axis camera was the way to go back then. From reading the description of your project, it sounds like it is exactly what you are looking for.

Mail me if you need to know more details.

No, try the AXIS WebCam...

[[Dilbert]]

This is NOT the way to go. I had to look up stuff for webcams/daycare last summer as an intern and I'll tell you that you don't want a computer if you don't need it...

We needed one or 2 cameras. The best way i could find to do it was with an ISDN line to the daycare center and an ISP, using an ISDN router. There is a webcam made by AXIS technologies (don't know the http, look it up). It's a thinserver -- you can browse the camera directly and grab pics, using different urls/filenames for different sizes and qualities. I think it could do up to one pic/sec... Not sure. If the daycare had a PC in there, they'd get almost live feeds off the cams, and it'd all be ethernet and easy. AXIS provides cgi scripts to grab pics and post them on a "real" www server if you like, or you could just provide links to the pics directly (although in my case, that would've saturated the daycare's planned ISDN link..."

Look into it, and if you want more input, mail me - remove the "nospam".

"Half of everything you know is wrong." - My physics teacher.