CitySpace on mbone

Has anyone come up with a solution to this problem? I'd love to be able to broadcast graphics right off the screen on mbone.

From: Don Hopkins (hopkins@kaleida.com)
Date: Wed, 9 Mar 94 14:20:12 PST
Subject: CitySpace on mbone

We would like to set up an mbone connection from the Exploratorium, so we can use CU SeeMe on macs and the reflector on an indigo to broadcast video CitySpace flythroughs rendered on an onyx. The indigo has multicast in the kernel, and I fixed some setsocketopt bugs in the reflector and got it to compile with the multicast option on the indigo. Can somebody please help me set up a tunnel, and schedule a time to broadcast, or whatever else it takes?

Ideally I want a program that broadcasts pixels right off the screen, eliminating the need for alot of expensive equipment (described below), and improving the image quality by (ahem) not converting the pixels to analog ntsc and back. Does that program already exist? Any tips on how to implement it? Please reply to hopkins@kaleida.com, as I'm not on the mbone mailing list. Thanks!

-Don

Date: Tue, 8 Mar 94 19:36:19 PST
From: don@toad.com (Don Hopkins)
To: jim@tadpole.com
Subject: CitySpace CU SeeMee stuff!

We're setting up the CU SeeMee reflector stuff here at the Exploratorium! It works -- we have a mac with a video card that connects to the reflector, and other macs without video cards connect to it and see the image.

What can we do with the multicast option? We have an sgi with multicasting in the kernel, and I hacked the reflector to compile on that machine. How does the addressing and time to live value work? Do we need to set up a multicast address with the powers that be, or set up a tunnel to somewhere that is on mbone?

Also, do you know of a program that will take bits directly off the screen and broadcast them as video, without going through analogization and redigitizations? I could imagine a program that opens the raw framebuffer (in fact I just wrote one) and then writes to the reflector over a socket using this video protocol, but I don't know the particulars of the protocol. It might help to start with the CU SeeMee software, but I don't know where to get the source. But then you could easily broadcast full resolution right off the screen without any special hardware.

-Don