scan converters

Bob Olson olson at mcs.anl.gov
Wed Jul 5 12:31:02 CDT 2000


The problem with scan converting video of something you want to actually
read is resolution -- the h261 that will come out the vic driven by the
converter will be only 352x288 pixels, with reduced color quality as well.
The vnc solution will give you the full resolution and color depth.

--bob

On Wed, 5 Jul 2000, Allan Kenneth Spale wrote:

> Michael,
> 
> During the June Chatauqua, EVL displayed a video stream that ported video  
> directly from a Cray to the video capture card.  We did not have any
> serious trouble related to capturing and maintaining the video stream.
> The video quality was good, too.  Maybe someone else at EVL would
> be able to comment more on this subject as I am only a node operator.
> 
> 
> Allan  
> 
> On Tue, 4 Jul 2000, Michael Grobe wrote:
> 
> > hello:
> > 
> > the various complexities of using VNC for screen-sharing demos 
> > got me to thinking about alternatives.
> > 
> > has anyone tried using scan converters for these demos?
> > that is, in more detail:
> > 
> >    use a scan converter to take the VGA signal from a laptop
> >    or workstation and convert it to composite video for the
> >    video capture card for normal broadcast over the grid.
> > 
> > this would be MUCH simpler than the VNC approach (especially the
> > bi-level VNC approach invented by eric).  i suppose it would
> > be considerably lower resolution, so it would be unusable for
> > some demos or PPT slide sets.
> > 
> > i have found a cheap scan converter...well, relatively cheap...
> > $495 list price...i have a call in to see about an edu discount.
> > for similar quality (VSC-75 or VSC-100) the Extron edu price 
> > appears to be about $1000.
> > 
> > the product is the CORIOscan Select from tvone.com (www.tvone.com).
> > (up to 1024x768, composite, s-video, and RGB output, ntsc and pal 
> > switchable, scan rates up to 100KHz, etc.)
> > 
> > if nothing else this MIGHT make a reasonable backup tool for VNC
> > and dPPT, if it isn't good enough for general use.
> > 
> > :michael grobe
> > 
> 
> 




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