CUSEEME & TIA and testbed....

David H. Brown (
Mon, 6 Feb 1995 10:21:39 -0500

"Charles F. Brown" <>
Subject: Stereo Video (was Re: Run two copies of CU-SeeMe on one Mac?)
Message-ID: <Pine.SUN.3.91.950206094114.6426B-100000@jeeves>
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Pat, [in response to your e-mail attached below]

I see someone else is thinking along the same lines as I am regarding
stereo video using CU-SeeMe (see
/~dhbrown/stereo/stereo.html). I have been considering setting up a demo
using two Macs to source the left and right channels. This would be sent
to our reflector, allowing anyone with the desire to see a 3D session to
tune in. Given the general architecture of CU-SeeMe, I dont think you
could get two sessions running on a single machine without changing the
code. Instead of using two cameras, you could use a prism-like
attachment in front of the camera to create the appropriate stereo pair
input directly on the picture element. Of course this would yield images
only half as wide as normal.

If the developers were to allow for multiple streams from a single source
machine/IP address, and the application was stereo video, then it might
make sense from a bandwidth perspective to send one channel plus a
difference channel. The thinking being that the left and right images
would be highly correlated and thus the difference channel would contain
far less information (and thus require less bandwidth) than either source
channel. Of course this would then require mods on the receive side as
well to put the images back together.

I am somewhat curious as to what your application is. I am merely
prone to distraction. Do you have a specific use for this
other than the delta coolness factor of 3D. If you would like to run
some relatively closed demos on this or exchange ideas, we could take
this off-list.


David H. Brown - NASA Science Internet Engineering Support
Sterling Software -

> Date: Thu, 2 Feb 1995 07:56:27 -0500
> From:
> Subject: Re: Run two copies of CU-SeeMe on one Mac?
> In addition to concurring with Mark's suggestion, I would like to amplify
> it somewhat. One of the objectives that I am trying to achieve is
> sending stereoscopic video. I have been investingating several
> approaches, however I believe that separate instances of Cu-SeeMe is a
> highly desirable one (primarily because it allows me to separately
> buffer images to each eye). While this may or may not be of interest
> or concern to others, if the feature was available it would aid in my
> development projects.
> Best Regards,
> Patrick T. Stingley
> Just thought I'd throw this out to the developers as food for thought --
> maybe this is easy to do, maybe not.
> Is there anything done in CU-SeeMe that would prevent more than one copy of
> it from running on the same machine?
> Say for example I have two separate video sources - a VideoSpigot and a
> QuickCam. I want to set up CU-SeeMe #1 to use the VideoSpigot and CU-SeeMe
> #2 to use the QuickCam, then run both at the same time.
> This currently doesn't work - the second copy fails with an obscure error
> code about "Can't open MacTCP". And, of course, there may be a conflict
> with both copies wanting to use the same Pref and Nicknames files.
> So - is this totally out of the question?
> --Mark