Subject: VAT bug?

From: Yves LePage <[email-masked]>
Date: Wed, 11 Jun 1997 12:09:48 -0400 (EDT)

Hello,

During the video over IP session that is now finishing at the ICC97
conf., receivers have lost sound for a while. My VAT was still getting
the sound feed (according to the meter) but it wasn't transmitting it. 

This happened right after we started switching (with an audio switch/mixer)
the sound sources to present a video tape. 

Could this be a VAT bug?

Yves Lepage
[email-masked]

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From: Ian Reddy <[email-masked]>
Date: Wed, 11 Jun 1997 09:59:56 -0700 (PDT)

> the sound sources to present a video tape. 

I regularly use vat 4.0b2 on Solaris 2.5.1 and find that it always stops
sending if the audio source is stopped/resumed or switched. When the audio
resumes the SPARCstation will no longer be sending the audio stream even
though the "talk" button on vat is still depressed.

For this and other production reasons I've gotten into the habit of always
connecting another workstation (my ThinkPad for instance) next to the
multicasting workstation as a "monitor".

-- 
  Ian Reddy, Senior Systems Consultant  E-mail:    [email-masked]
  Academic Computing Services, AD1021              [email-masked]
  Simon Fraser University               Telephone: (604) 291-3936
  Burnaby, B.C. Canada V5A 1S6          Fax:       (604) 291-4242

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From: Bill Fenner <[email-masked]>
Date: Wed, 11 Jun 1997 10:47:38 PDT

>the sound sources to present a video tape. 

Did the application name down at the bottom italicise itself?  If you
don't have "Keep audio" or "No silence suppression" set, then vat will
release the audio device after a period of silence (since it thinks
you're done).  When you're transmitting a session you should always
have "Keep audio" set.

  Bill

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From: Stephen Casner <[email-masked]>
Date: Wed, 11 Jun 1997 11:00:56 -0700 ()

> though the "talk" button on vat is still depressed.

Unless you click on the "Keep Audio" button, vat will release the
audio device after a timeout (20 seconds or so) if the input silent
and silence suppression is in effect.  Without input from the audio
device, vat cannot tell if the input becomes non-silent again, so it
remains in the same state.  The solution is to set "Keep Audio".

This problem does not arise when operating in a push-to-talk scenario
because the button push requests the audio device.  You can tell when
vat has released the audio device because the program name/version
text at the bottom changes to italic.

However, this may not be the problem Yves saw because he said the
meter on vat was still moving, which indicates that vat still had the
audio device.
							-- Steve