by Larry Gilbert
What would George Orwell think? One chilling prophecy of his most well-known novel, 1984, has come true within 11 years of the time it portrays. Television cameras, linked by a global electronic network, peer at streets, offices, and households throughout the world--and more are being linked up every day.
However, that probably wouldn't have surprised him as much as the fact that anyone is allowed to take a peek through these digital port-holes. And what would he make of the reasons why more and more people are willingly making these cameras available: admiration of parrots and fish? remote operation of model railroads? monitoring of a coffee pot across the building (or across the Atlantic)? sales of chia planters?!
The World Wide Web has spawned a curious Internet-wide fad: ``Web cams''. And curiosity may well be what keeps the idea going. Browsing a list of such cameras is like being a virtual tourist or (some might accuse) a Web voyeur. While it may take a bit of an intuitive leap to think of a Web page as being somewhere else in the world, having an up-to-the-minute snapshot on the page drives the point home to anyone. How else can one explain the fascination with gazing at a bus terminal in Berlin, mountains in Norway, an iguana cage in California, a home office in Texas, or a total stranger's feet in the UK?
You who are reading this magazine may already be caught up in this fad, looking to get in on it in your own little way. That's what this article hopes to help you do, first by summarizing what makes a Web cam tick, then by pointing you toward more specific information available on the net.
People open up their vistas to the Web for many reasons. Some of the main ones:
Assuming you've already decided on your planned Web cam's purpose (or lack thereof), setting it up involves tackling four main problems.
Once you've found a camera with standard video output, you'll need a video capture device or ``frame grabber''. As mentioned above, some cameras don't require one, but most do. Some lucky people, like those with a Macintosh Quadra AV or an SGI Indy, don't have to worry about this part--they've got video inputs built into their machines. But the rest of you need not panic; frame grabbers are easy to find at most computer stores, some as low as $200. They're available from a number of manufacturers, including Creative Labs, Vigra, Radius, Play, and others.
Once you're finished setting up your hardware and expending your Visa card, you'll have to get your computer to grab a video image from your camera and store it at a regular interval. Then the image has to be stored as a GIF or JPEG on a public HTTP server if anyone's going to look at it. (Setting up an HTTP server is a matter for another article, but there's plenty of information about that on the Web already). [And coming up in this magazine. -Ed])
One of the most commonly-used setups works this way: A script (or batch file to you DOS heads) executes the appropriate frame-grabbing utility, runs a conversion utility to go from the frame grabber's image format to GIF or JPEG, copies the final image to an HTTP server via a local network connection, and the whole process repeats after a time. This process allows a low-cost computer to act as a dedicated camera server and lets the big, powerful HTTP server handle all the image requests. It is also a good setup choice when the camera is on a remote computer with no connection to the outside world other than PPP or SLIP (in that case the camera server has to do a dial-up and a login every time it has to copy an image). If the computer with the camera is powerful enough, and if it has a high-speed net connection, it can act as the HTTP server itself. Then, instead of linking to a stored image file, the camera link on your server can link to a CGI script that grabs a video frame and converts it on the fly, providing a truly live snapshot. (Got that?) If you wanted to get really fancy--and if you don't give a rip about browser compatibility--you could take advantage of ``client pull'' or ``server push''; on browsers like Netscape Navigator to provide continuous, albeit painfully s-l-o-w, real-time video. Cool.
This sounds like a lot of work, but at this point you have yet to solve the toughest problem of all...
Yes, it's likely that most people in your life just don't understand what the World Wide Web is, let alone why you might get excited about hooking all this equipment up to it for no apparent reason other than to let others invade your privacy. How might you sum things up for them in a nutshell? Here's some ideas for what to tell them:
Wherever George Orwell is, you're giving him something to laugh about.
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