Desktop Programs Plug Into Video
When Bill Clinton and Al Gore went stumping through Silicon Valley last month to rally support for their industrial policies, they stopped at a computer company called Silicon Graphics to speak with employees. About 200 people gathered in the company cafeteria to hear the President speak in person, while hundreds of others listened and watched from video-equipped computer screens at their desks.
While Clinton and Gore were calling for the development of a nationwide computer “super highway,” their images and voices were being transmitted over Silicon Graphic’s internal computer network and, worldwide, via Internet, a much larger network used mostly by academic and corporate researchers. The Clinton-Gore proposal would link schools, libraries, businesses and homes with a rich assortment of audio, video, graphics and text as part of a national data network.
Though such a national network would cost billions of dollars and take years to develop, some technically savvy companies already are sending video images over in-house networks.
Before a video signal can be sent via a computer network, it must be digitized into millions or even billions of bytes, straining the capacity of today’s networks. The video must also be compressed before it can be transmitted. Instead of the normal 30 frames per second used by TV stations, Clinton and Gore’s images were being transmitted at about 5 frames per second.
Compressed video is choppier than what we’re used to seeing on TV, but it is adequate for relatively static presentations such as a presidential speech. However, you wouldn’t want to watch a basketball game or a dance concert in this format.
Silicon Graphics, a Mountain View-based company known for producing special effects for Hollywood movies, used its own equipment to compress, transmit and display the presidential remarks. Similar technology, however, is also available on IBM-compatible and Macintosh computers.
So far, there aren’t any high-speed data networks that allow ordinary PC users to view high-quality video presentations, but several important pieces are falling into place. For example, PCs and Macs can now be used to create and view full-motion video. Apple’s QuickTime (for Macintosh and Windows) and Microsoft’s Video for Windows make it possible to digitize and compress video images so that they can be stored on a disk and displayed on a standard computer screen.
Even with compression, it’s not possible to squeeze more than a few minutes of video on a floppy disk, so compact discs (CD-ROMs) are now the most popular format for distributing video images. The newest versions of both Compton’s Interactive Encyclopedia for Windows and the New Grolier Electronic Encyclopedia, for example, contain numerous short video segments.
Several companies, including 50/50 Micro Electronics (800-245-5050), offer plug-in boards designed to let you watch television on your PC screen. Turning a PC into a TV is an awfully expensive way to watch TV, but there are practical uses of the technology.
For example, the $499 Video Blaster board from Creative Labs (800-998-5227) lets you connect an IBM-compatible PC to a VCR, laser-disc player, camcorder and other standard video sources. You can watch the video in a window on your computer screen and, at any time, stop the action and capture an individual frame to use in a document or a database. It’s a good way to get images of three-dimensional objects into a PC, though the quality of the images is inferior to those produced by a digitized photograph and a good color scanner.
You can also use the board as part of a computer-based training system. Several companies publish training programs that use software to control a laser disc player or VCR. Typically you need both a PC screen and a TV monitor to use such a system, but the Video Blaster board enables you to view computer data and video on the same computer screen.
Computerized video communication isn’t just a one-way street. ShareVision Technology (408-428-0330) of San Jose recently introduced the ShareView Plus desktop visual communications system, which transforms a Macintosh into a very sophisticated video telephone. Users can not only see and hear each other but can simultaneously collaborate on the same document via a single standard phone line.
The system costs $4,500, but the cost of such systems is expected to decline over the next few years. ShareView Plus allows you to create a “white board” so both parties can draw sketches, type notes and paste in graphics that can be viewed and modified just as if you were in the same room. While you’re talking and watching each other you can also collaborate on documents, spreadsheets, databases and other applications. A $1,195 version provides audio communication, document collaboration and access to the white board, but does not include the video phone. The company plans to introduce a Windows version later this year.
