Re: Audio lock-up with MacI

M_Baldizzi (
Thu, 5 Jan 1995 16:44:15 -0500

Subject: Time:4:30 PM
RE>>Audio lock-up with MacII Date:1/5/95
Fred S Long wrote:

Fred>> I'm using a Quadra 800, 72MB, no camera, OS7.5 with
Fred>> MacTCP2.0.6. My network connection is
Fred>> ***Added in forwarding* using
Fred>> version 0.70b15 After starting CUSM, it works for
Fred>> about 5 seconds then the sound stops. The video continues
Fred>> OK. Sometimes I can click the speaker icon at the bottom of
Fred>> the video frame and the sound will be okay for another 5
Fred>> seconds.Sometimes the sound wont return. The sound is pretty
Fred>> badly broken up when it does play -which I attribute to our
Fred>> reasonably high network traffic. The reflectors I use are at NASA,
Fred>> NYSERNET, and the campus radio station at UNC [no video]. Do
Fred>> you have any reason to think it may be refelector [refelector version]
Fred>> sensitive? wrote:

Doug>>The sound problem seems to be a large
Doug>>mess. I have also had the same problem here. I just
Doug>>received a message from developer Larry Chace
Doug>>( The audio is being worked on by Maven, the
Doug>> people whose audio software is used in Cu-SeeMe.
Doug>> As for the MacTCP Watcher, I can confirm your observations.
Doug>>I don't know how they are sending Cu-SeeMe. I
Doug>>would like to encourage you to post your audio problem to the
Doug>> group. I have had MANY people saying they have the same
Doug>>problem e-mail me directly rather than posting to the group.
Doug>> I think our Mac audio problem is under-appreciated. Please
Doug>>help correct that.

Fred, Doug and others experiencing this audio problem,

I have been experimenting with delta modulated audio
(CU-SeeMe..70b14 or newer) on the NASA TV feed. Since I changed,
I've experienced the symptoms you describe. If I connect to any
reflector with users using the default audio encoding (Intel DVI)
before connecting to the NASA reflector audio quits after a few
seconds. However, if NASA TV is the first reflector connected to
after CU-SeeMe is started it works fine. It seems as though the two
encoding schemes interfere with each other. The bandwidth savings by
using delta-mod eliminated the audio choppiness and is an
improvement for some viewers using 56k and ISDN circuits. I'm
hoping the incompatibilities between the delta-mod and DVI, and non
support of delta-mod by vat won't force me to go back to the
default setting and an additional 16kb/s. Please let me know what
you think.

Michael Baldizzi MS142-1 Phone 216-433-5120
NASA Lewis Research Center Fax 216-433-8000
21000 Brookpark Road email
Cleveland, OH 44135