clouds@ccwf.cc.utexas.edu (Kathy Strong) (11/21/90)
I received this in mail, and thought I'd pass it along.
================
From seb@lns61.tn.cornell.edu Mon Nov 19 18:10:15 1990
Date: 19 Nov 90 19:08:00 EST
From: "Selden E. Ball, Jr." <seb@lns61.tn.cornell.edu>
Subject: Re: How much can be put on a videodisc
To: "clouds" <clouds@ccwf.cc.utexas.edu>
Kathy,
You recently posted a message to comp.ivideodisc.
(Message-Id: <39941@ut-emx.uucp>)
Unfortunately, your description of how one can freeze a frame and play
audio from another part of the disc is only true if one has a
high-end player (like the Pioneer LD-V8000) with a built-in frame store
or if one is using a computer that has a built-in frame grabber. Both of
these options are expensive enough that most interactive systems don't
have them.
Selden
(Someone at JPL is kind enough to forward comp.ivideodisc postings to
me, since I don't have direct access to Usenet at our lab.
If you want to post this for me, that's ok.
There's supposed to be an address at UCB that forwards messages
to a specified Usenet group, but I've managed to lose the
documentation.)
Selden E. Ball, Jr.
Cornell University Voice: +1-607-255-0688
Laboratory of Nuclear Studies FAX: +1-607-255-8062
Wilson Synchrotron Lab BITNET: SEB@CRNLNS
Judd Falls & Dryden Road Internet: SEB@LNS61.TN.CORNELL.EDU
Ithaca, NY, USA 14853-8001 HEPnet/SPAN: LNS61::SEB = 44283::SEB
===============
Whoops... I've made the common mistake of confusing my immediate environ-
ment with the universe. :-) We are indeed using the Pioneer LDV-8000 units
and I wasn't giving much thought to the fact that this is kinda posh equipment.
Since we have frame-grab capability on our players, I haven't done much nosing
around into overlay cards that can do that same job. Comments? Experiences?
Recommendations, anyone?
Frame-grabbing with the player is something that many authoring packages don't
have a command for--we do it by sending the command string directly to the
player. I had a funny experience when I first started working with stills--it
seems that they'd work MOST of the time, but about once every five to ten
grabs, it would just "miss" the grab... that is, it would find the visual frame
but instead of "grabbing" it while it moved to the audio part, it would seek
the audio and let that video show through (i.e., video passthrough was NOT being
disabled). No apparent correlation between this problem and location on the
disc, distance between audio and video, or any other damn thing. After several
days of trying everything I could think of to pin it down, I finally discovered
what the problem was--my computer was too fast. Simply adding a .02 second
pause between the "grab" command and the "seek audio frame" command made the
problem disappear without a trace. Now, whenever ANYTHING strange happens
between computer and videodisc player, the first thing I do is insert pauses.
So much for state-of-the-art instant-random-access technology!
--K
--
...........................................................................
: Kathy Strong : "Try our Hubble-Rita: just one shot, :
: (Clouds moving slowly) : and everything's blurry" :
: clouds@ccwf.cc.utexas.edu : --El Arroyo :
:..........................................................................: