Need help running USB web cam over large distances

USB has an inherent limit of around 5M. I have seen USB repeaters that use cat5, e.g.

Of course you could just use composite analogue and a multi-channel capture card at the PC end.

Cat5 aint a signal. It is a cable. The cable can carry whatever signal you want, but it is a twisted pair (TP) cable, thus not suited for some signals. USB is _not_ made for TP cable, and would probably give worse results than using a loooong usb cable.

It ain't a video signal as such. It is digital information, whatever this information is a video format, a word document, sound or whatever, it has to be undamaged when arriving into the pc.

What I guess you're looking for is some way to convert the USB signals to Ethernet signals, which can run 250M on CAT5E cable by the specification.

--
MVH,
Vidar

www.bitsex.net

There are devices for converting USB to a form which allows transmission over CAT5 over fairly long distances. Here's one (the URL probably won't wrap right. Sorry.):

Google on USB extension, or USB extender.

Why not use network based cameras?

If you want to mess with sending video over CAT 5 (eg rather than digital data)...

system.

I'd

Well, you can stop at 300 feet or 90 meters. If the cat5 has been installed to the EIA/TIA 568 specifications, it will not be longer than that. Of course you can pull a fast one, and put a jumper cable from jack to jack at the patch panel. That will make the maximum 181 meters ( about1 meter for the patch cable). Or you could just say that your product must have a gizmo to amplify the signal at the patch panel to do that. Make more money that way. ;-)

I did a google search for cat5 security camera and got 90 thousand hits, so it looks like you've got a lot of competition. :-(

More and more, Colin, this makes sense to me and the Axis 205 seems like the best option out there on the market right now. I just can't seem to get these cheap USB cameras to do simultaneous video and no one else does either.

I see it comes with a built-in web server and built-in MPEG display playback. The question I have now is how can I download Axis 205 data from the unit to a PC so that it can store this and allow a security guard to review it backwards in time? Can I use a command-line Linux tool for that?

You would have to look at the manual. There are many program that can record streaming video but I suspect this camera may come with something to do just that.

to

Actually now that I've scanned the review I see it says...

"Axis does not offer the ability to directly capture video streams from the

205. However Axis does offer the "Axis Camera Recorder" application, which allows you to capture and save video. This is professional security level software and, according to what we were able to find out, it is not currently compatible with the 205. Since the software is expensive and the 205 is an entry level product, don't expect support for this feature anytime soon."

In which case you might want to look at other models from their range or other manufacturers products.

Darn. I knew there had to be a catch. Any other camera would be out of my price range for this very inexpensive (but functional) system I'm trying to build. I was just getting frustrated with simultaneous live video from multiple USB streams. Looks like I'll have to just do snapshot downloads, and if I'm going to have to do that, I might as well use USB cams because they're just functional enough for my needs and are extremely cheap. You can get a fairly good one for $36 these days. I've noticed when I look at security packages, they are only showing the image about every 1 to 3 seconds, which should be good enough for me.

I guess I can use streamer or gstreamer to grab snapshots from the USB cams. This creates a PNG which I can then display in a web browser. I can create a web page which updates a frame every two seconds, downloading a new PNG. Or, if I can find a Java applet, I can use that to load the PNG every so many seconds. If anyone can recommend a good, free Java applet for that, please let me know.

snipped-for-privacy@hotpop.com wrote: You can get a fairly good one for $36 these

Went into a grocery store today and saw MPEG4 cameras plugged into a quad multiplexer. The images looked about 2 or 3 per second, simultaneously, on each frame of the quad screen. I can do just as good by using the Linux "streamer" command-line tool with $25 USB cams and CAT5 USB extenders, hooking it all through a Linux PHP website. I've got a demo started today with 2 cams, but I haven't tested the CAT5 USB extender jacks yet. I'll probably purchase that this week and will do my 100 foot test to see if the images still work.

I'm going to be on the lookout for a Java applet (or may build one myself) or Shockwave file that loads a JPEG image every so many seconds from the web server.

You might find cheaper..

Wired network cam $94 Wireless network cam $149

Turns out that someone has figured out how to do video extraction from the Axis 205 from Linux command line:

wget -q -m -N -nd -L -l2 -Y off --http-user=root --http-passwd=*****"http://192.168.29.46/jpg/image.jpg"

There are some products that claim to be able run USB signals through CAT5 UTP wiring. They go somehow longer distance than normal USB cables, but I don't think they can extend the maximum lengthof USB network.

If you really want some longer distance than few meters, I would recommend to use some technology that is designed to work over the needed distance in the beginning, rather than pushing the USB techology that is originally designed for short distances only.

Technologies that are suitable for longer distances over CAT5 wiring are webcams with Ethernet interface (normal Ethernet networking limits) and CCTV cameras designed for UTP wiring signal transfer connected to video digitizing card/device on the computer end (works well up to several hundred meters).

There are real technical reasons why USB cables have their distance limits, and why the cable used with USB devices is different that CAT5 cable. CAT5 cable is not the optimum medium for USB signals... Maybe not worth to take apart an expensive web camera.

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Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/