Re: [GnomeMeeting-list] Unexpected behavior between GM and RadVision MCU after MCU upgrade

[Craig Southeren <craigs postincrement com>]

On Fri, 27 Feb 2004 14:40:44 -0800
"Kevin Oberman" <oberman es net> wrote:

..deleted

> > 1) You changed the MCU, and the behaviour changed. GM did not change. So
> > why do you think this is a GM problem?
> 
> I don't think it's a GnomeMeeting problem, but ViaVideo works the same
> as before while GnomeMeeting does not. So there is something in GM that
> is interacting with the new MCU differently from other clients (or at
> least, ViaVideo).

I have to disagree. The MCU is behaving differently, whereas GM has not
changed. So the changed behaviour is in the MCU, not in GM.

> > 2) The endpoint has no control over the video being sent to it - it can
> > only display what the MCU sends. 
> 
> Clearly this is not the case as ViaVideo does display a screen with four
> images in a 2x2 array while GM only displays a single image the size of
> one quadrant in previous version.

As one of the authors of the OpenH323 protocol stack, trust me when I
say that the client only displays the video that is sent to it. 

This could be something as simple as the ViaVideo client using the H.263
video codec, which allows larger video sizes than the H.261 codec
supported by GM. Perhaps the new MCU does not support split screen for
H.261 endpoints?

> > 3) The new behaviour (video following the current speaker) sounds like a
> > plausible mode for an MCU to use. I suspect there is a mode somewhere in
> > the MCU that switches between this new behaviour and the old behaviour.
> 
> I agree. But it is clearly controlled by the client. I suspect it is an
> option that is negotiated differently by Via Video than by GM. It may
> even be configurable on the MCU. I'm just trying to figure out where to
> look. (Yes, I am also talking the MCU support people.)

If a fix requires changes to the protocol stack, then let me know. I'd
be interested to know what is causing this change in behaviour.

   Craig

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