Workstation video Summary

[Randy M. Rohrer]

A while back, I asked for suggestions for capturing live video from
workstations. Thanks to everyone who responded (this net is great). The
following is a summary of responses.  I might add that we are considering
buying the YEM real-time product.

	Randy Rohrer
	rmr at mimsy.umd.edu 
__________

original posting:
> 
>    Any suggestions out there for low cost, relatively low quality
> video production?
> 
>     Our environment includes a variety of workstations such as
> Sun, Apollo, SGI, etc. We are looking for a good way of making
> our own videotapes directly from these workstations. We think 
> that VHS-quality is sufficient (although we may be disappointed).
> 
>      We are currently perusing the market place for real-time
> digital scan converters that convert RGB signals to video output.
>  
>      Offerings have been found from Lyon-Lamb, RGB Technologies,
> and YEM (Yamashita Engineering Manufacture, distributed in US by
> Grunder and Associates). In general, they run about 
> $12,000 - $20,000 depending on features and quality.
> 
>    This project is currently a research project so initially
> low quality might be ok. We may eventually like to go to
> higher quality recording devices and formats.  
> 
>      Has anybody had any experience with these products or 
> or other products which you would like to share? Are there 
> better methods available? Will we be sorely disappointed in quality
> going from 1024 scan lines to ~512 ?  
> 
>     Any help, comments, or re-direction would be appreciated.
__________

responses:
__________

From: uunet!haven!ames!hoptoad!unisoft!peritek!dig (David Gotwisner)

We have an RGB to NTSC (for VHS format VCRs) converter we sell that takes
an RGB input (such as what is output from your graphics device) and
generates NTSC (RS170A) compatible output (which is what plugs into your
VCR).

I actually know little about this product, as I had nothing to do with the
project and it is a new product.  Pricing is around $700 for a standalone
(plugs into the wall) version.

I have seen it used with some of our 512x512x(8 and 24) graphics boards
and the output looks good (for NTSC).

If you are interested in finding more out about this, I suggest you call
our factory and ask for Jill (phone: 415-531-6500).

Hope this helps.

Dave
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From:    "Norman C. Kluksdahl" <uunet!haven!ames!asuvax.asu.edu!enuxha.kluksdah>

We have been using the Lyon-Lamb encoder/sync generator in conjunction
with a graphics workstation which has a Genlock option.  Without this
option, encoding the color may be unstable.  SGI does make a Genlock board
for their workstations, and I have seen that work.  

The Lyon-Lamb high-res:NTSC encoder I saw (last year) was not capable of
converting in real time; it captured an image and then produced the NTSC
image: net time was about 1/10 sec.  Folsum (I don't have an address-- if
there is a Stellar office nearby, they would know)  can produce an NTSC
encoded image from high-res in real time, but we had some questions about
the stability of their converter.  That box is ~10K.  Lyon-Lamb's was ~20K.

If you use a frame-capture procedure, then you MUST get an animation
controller if your video will consist of multiple scenes.  Again, we use
the Lyon-Lamb box-- the VAS 4 is ~ 9K, and will directly control a VTR.

When it comes to the VTR, by all means go with a 3/4" machine if at all
possible.  The VHS machines only give ~250 lines, and the resolution
sucks.  We use a Sony 3/4" VO-5850 machine (~8K).  The videotape is
excellent.

Good luck with whatever graphics equipment you choose.  If you have any
further questions, feel free to get in touch.


Norman Kluksdahl              Arizona State University
            ..ncar!noao!asuvax!enuxha!kluksdah
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From:    Craig F. Reese <cfreese at super.org>

I have done some simple recording down here.  Since we didn't have any
fancy equipment, I simply pointed the Panasonic video camera at our
Sun3/260.  The results weren't the best in the world, but I attribute that
mostly to VHS.  Anyway, when thinking about buying a nifty box, I began to
wonder how well it might work.  In my video I wanted to zoom in on control
panels, plots, etc...  I suspect that the "boxes" simply let you record
the whole screen.  Something to think about anyway....

I'd be interested in any more information that you find.

craig
Craig F. Reese
Institute for Defense Analyses/Supercomputing Research Center
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From:    denbeste at BBN.COM

You might consider getting a TV camera and hooking it up to your VCR.

Get a telephoto lense, and move the camera way back - this gets rid of
most of the distortion caused by the curved screen of the Sun monitor.

I suggest you run with a big character set in your windows, and use a dark
room and low intensity level on the monitor. Open the camera aperture as
far as it will go. This should cut down on the flicker.

At current market prices, you should be able to put such a system together
for about $1000.

Steven C. Den Beste,   BBN Communications Corp., Cambridge MA
denbeste at bbn.com(ARPA/CSNET/UUCP)    harvard!bbn.com!denbeste(UUCP)
__________

From:    wyatt%cfashap at harvard.harvard.edu (Bill Wyatt)

A research group here (Smithsonian) recently purchased the Yamashita unit.
It's great! I've seen very nice RGB / RS170 converting from a VaxStation
8000 at 1024x864. I am not directly part of the group, but they are across
the hall from me so I've picked up a lot. The guy who did the product
research (Bob McMahan, mcmahan at cfa.harvard.edu) says the other units
lacked important performance features. The LL unit, for example, is only
about 10 Hz, and drops scan lines. The Yamashita does 60Hz and
interpolates to get 512 line output. It's pricey (~22k list) but he thinks
well worth it compared to the others, as it can convert to several formats
simultaneously.

Bill Wyatt, Smithsonian Astrophysical Observatory

UUCP:  {husc6,cmcl2,mit-eddie}!harvard!cfa!wyatt
ARPA:  wyatt at cfa.harvard.edu
 (or)  wyatt%cfa at harvard.harvard.edu
SPAN:  cfairt::wyatt 
BITNET: wyatt at cfa2
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From:    attcan!utzoo!henry at uunet.UU.NET

Have you considered just pointing a video camera at the screen?  This
worked for us at CHI+GI 87.  (NB, it may matter whether the camera uses
image tubes or solid-state sensors.)

	Henry Spencer at U of Toronto Zoology
	uunet!attcan!utzoo!henry henry at zoo.toronto.edu
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From:    <cws at bigfoot.math.ufl.edu>

There was a stream on this problem a while back -- e.g. from sun-spots.v6.176:

  Date:    Wed, 3 Aug 88 18:57:35 EDT
  From:    henry at zoo.toronto.edu
  Subject: Re: Sun video to VCR

  >Does anyone have any experience capturing the video output from a Sun
  >workstation to video tape?  ...

  There is a non-trivial problem here, because the Suns (at least, the ones
  I'm familiar with) use very non-standard high-speed video that your video
  tape gear will not understand.  No way, no how.  Scan conversion between
  video formats is possible but outlandishly expensive.  Almost certainly
  the simplest thing to do is to just point a video camera at the screen.
  This works better than you'd think.  We did it quite a bit in the CHI+GI
  87 demos sessions (which I was co-chair of), and had only one real
  problem: you must bear in mind that conventional video gear simply cannot
  reproduce the resolution of a Sun screen, meaning that you have a choice
  of a sharp closeup of one part of the screen or a fuzzy overall view.  If
  you want detail, you'll need an alert cameraman who can zoom in on the
  right parts of the screen at the right times.
  
        Henry Spencer @ U of Toronto Zoology
        uunet!mnetor!utzoo!henry henry at zoo.toronto.edu