Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!celit!soledad!hathaway
From: hathaway@sea.com (Rob Hathaway)
Newsgroups: comp.ivideodisc
Subject: Re: How much can be put on a videodisc
Keywords: videodisc, size
Message-ID: <1990Nov19.220958.8852@sea.com>
Date: 19 Nov 90 22:09:58 GMT
References: <10527@ur-cc.UUCP> <39941@ut-emx.uucp>
Sender: Robert A. Hathaway
Organization: Systems Engineering Associates
Lines: 30

In article <39941@ut-emx.uucp> clouds@ccwf.cc.utexas.edu (Kathy Strong) writes:
>Quick answer: there are two types of videodiscs: CAV (constant angular velocity)
>and CLV (constant linear velocity). 
> ...
>Due to my constitututional inability to deal with acronyms, I forget which
>is which--but I believe the faster one, the one that has 30 min/side, is the
>"standard."

This is CAV.  As far as I know, CAV is more common in interactive video
applications.  But it may be easier to find CLV disks (sometimes called 
"Extended Play") for your home videodisc player (i.e. for movies).

>Of course, that's 30 minutes of motion video. Most videodisc programs make
>good use of the fact that you can have two to four tracks of audio as
>well. Example: seek frame 4000, a still of Terra as seen from space, disable
>video passthrough (i.e., "grab" or "freeze" the image), move the heads to 
>frame 6000, play 15 seconds of narration from audio track B.

The ability to "grab" an image while playing other frames may depend on the 
overlay circuitry you are using.  It may also be a feature of the player. 
This feature is, however, becoming more common, so make sure you look for
it in the hardware you buy in the future.

>--Kathy
>
>(Help! I feel like I'm the only person talking on this newsgroup...)

Not any more :-)

-Rob