a253@mindlink.UUCP (Michel Gascon) (11/20/90)
--Kathy
(Help! I feel like I'm the only person talking on this newsgroup...)
Don't give up there is a couple more fellow reading it than writing to it.
--
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Michel Gascon Never enough of anything
I take it if it's free
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$larry@xanadu.Berkeley.EDU (Larry Rowe) (11/22/90)
I've been watching this newsgroup for almost 12 months and this is the first time I've seen anything really happening. I too would like to find a newsgroup that a ``computer literate,'' ``audio/video and hypermedia novice'' could read to exchange information and ideas. Rather than argue about names, I'd rather just start using this group for what we want to discuss. In the interest of generating some traffic and interesting discussion, I'll tell others what I'm up to and summarize what I learned about S-video last night that clarified for me the frustratingly confusing jargon I see on rec.video. 1. My Research I'm a faculty member at U.C. Berkeley in the Computer Science Division. My research interests are GUI application development systems and multimedia interfaces. (Aside: at the multimedia conference in SF a couple of weeks ago someone suggested that we'll soon be moving to MUI applications -- multimedia user interfaces.) I'm currently working on a shared video database and real-time conferencing testbed. The testbed includes a multimedia workstation, a high-speed local area network, and a high-bandwidth, large capacity storage system. The multimedia workstation includes a conventional high performance Unix workstation (Sparcstation) with a video-window board (RasterOps), mouse, keyboard, microphone, and speaker I/O devices. The workstation also will have a symmetric video compression board so that real-time video can be captured and displayed in the video-window. The local area network (Ultranet - 25 MBytes/sec host interface) and storage system will be used to support real-time video conferencing and to store hypermedia applications that can be simultaneously accessed by several workstations. The storage system is a disk array system (RAID) being developed by another group at Berkeley. Their next system will use DAT's to store data (approx. 1 GByte/tape) with a robot to load the tapes into one or more readers (possibly 4 with byte striping for high bandwidth transfers). The video compression board is being design and implemented by another student here at Berkeley. And, we're going to use a VME chasis and single board computer to build the network interface controller to the ultranet. Finally, we have a hypermedia system that we implemented in an interface toolkit, named Picasso, that we built in Common Lisp and the Common Lisp Object System that runs on X. We've already interfaced a Pioneer Laserdisc to the workstation and developed some applications that display video segments and images stored on the disc. Since the video we had wasn't stereo, we also built an audio help system for one of our applications using the other channel that is similar to the help system on the Next. We're hoping to be able to display video read from the storage server using the video compression board by the middle of next summer. If you or someone else is interested in talking to me more about this project, please send me email or call (415-642-5117). 2. S-video Now, I've been totally confused by all the jargon on rec.video about different video cameras, recorders, and editing systems. A couple of months ago I found a delightful paperback book that explained the basics of TV technology. The book is titled ``The Electric Image'' by M.A. Krupnick (available from Knowledge Industry Publications in White Plains NY, 914-328-9157). It explains everything from scanning theory, NTSC color, signal switching and mixing to magnetic recording and videotape editing. It really clarified a lot for me. But, I was still confused about what VHS, S-VHS, Beta, ED-Beta, 8mm, etc. meant. Last night I read an article in a local magazine that clarified it for me. Many of you probably know that NTSC is the video signal that is broadcast to your homes through the air or on cable. It is a single analog signal that encodes both a black&white image (called luminance) and color information (called chrominance). The color info is overlayed on the B&W image so that old TVs can still receive pictures even though they are broadcast with color. Putting these two signals together in the NTSC scheme causes information to be lost and distorted. S-video, which stands for separation video, encodes these two signals separately. Consequently, images recorded in s-video and played back on standard TVs look much better than NTSC images. In fact, it looks comparable to the images you get with a laserdisc. Now for the jargon. You also probably know that there are several different formats for video recorders: BETA, VHS, and 8mm. What I didn't know was that each of these formats has an s-video version: ED-BETA, S-VHS, and HI-8, respectively. The consumer electronics giants are producing cameras, vcr's, and other devices that provide a complete product line for their chosen market. The person who wrote the article suggested that computer folks interested in multimedia ought to be looking at s-video camcorders, vcr's and editing decks to produce their video segments. He suggested Sony's HI-8 camera (V-5000?) as a good camera that costs around $2.5k. He also mentioned the NEC PC VCR that evidently has an rs-232 interface as a good vcr for connecting to computers to build an editing system. ------------------------- Enough for now. If folks are interested, I can continue with the memory dump of what I've learned about video and multimedia over the past 18 months including a trip report on the Multimedia Conference held in SF recently and the Video Exposition held in SF last spring. larry