🚀 go-pugleaf

In article <91031.160311ICSJHH@ASUACAD.BITNET> Jim Howard writes:
> Has anyone heard of a jukebox version of a videodisk system, or
> of anyone attaching a videodisk to a system to act as a server for
> images or data from video disks. I know you would need a high bandwidth for
> full motion type images, but I am looking at creating a server that would
> have standard magnetic, CD-ROM, Magneto-optic read/write media and perhaps
> videodisks as resources available.

Well, there are a lot of imbedded questions here, so I'll try to do
my best.  First off, it's unclear to me when you say "videodisks" whether
you mean optical WORM discs for digital storage, or analog CAV/CLV video
discs that you can buy at The Wherehouse.

For the latter, I know that Pioneer offers the "LC-V330 Industrial Laserdisc
Autochanger" which provides jukebox like capabilities for their LD-V2200 and
LD-V4200 Laserdisc players.  Both these players are computer controllable
laserdisc players, and cost in the $1K range.  I don't know the cost of the
LC-V330, but it can hold up to 72 discs.  The MIT media lab did a system called
Galatea that used this type of storage for video.

If you're talking about WORM drives and the like for digital storage,
Sony produces a jukebox that holds about 3.5 TB of tertiary storage.
I doubt the bandwidth of the jukebox will be high enough for multiple
readers of real time video.

As far as other devices go, some people are looking at 4mm DAT
tapes as tertiary storage devices.  I heard of a device that costs $25000,
and stores 75TB of information in a carousel of DAT tapes.  Talk about
lots of cheap storage!

The problem of this tertiary storage is access time.  With DAT tapes, it
could take minutes to get to the data.  The obvious answer is to
use secondary storage (magnetic disks) as a cache for the tapes. This
secondary store would have to be large (1 hour of video, compressed,
is in the 1-5 GB range), but I expect that amount of storage to be not
uncommon in the next 5 years or so.

> With the appropriate video cards in both the server and workstations
> and a fiber or FDDI type high speed link an "image server" could be
> developed. Any research or practical work in this area?

A lot of people are doing research in this area (myself included).  A
good starting point for research is to look at the "IEEE Journal on Selected
Areas in Communications, Volume 8, No 3, April 1990".  The issue is
devoted to Multimedia communications, and will give you a dozen or so
relevant articles.

-----
Brian C. Smith				arpa:  bsmith@postgres.Berkeley.EDU
University of California, Berkeley	uucp: uunet!ucbarpa!postgres!bsmith
Computer Sciences Department		phone: (415)642-9585

-----
Brian C. Smith				arpa:  bsmith@postgres.Berkeley.EDU
University of California, Berkeley	uucp: uunet!ucbarpa!postgres!bsmith
Computer Sciences Department		phone: (415)642-9585