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I think this is motivation to enhance the AG streams to use SSM - then
you could select which source multicast streams you want to receive,
which would permit those on low bandwidth connections to choose how to
spend their bandwidth.<br>
<br>
George Estes wrote:
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cite="mid5.1.0.14.2.20070202083029.02db72e0@pop.ncsa.uiuc.edu"
type="cite">
<pre wrap=""> Being able to select which video streams to receive would definitely be helpful in our project to deploy PIGs to K-12 schools. Many of these schools are bandwidth challenged. We have been looking at ways to minimize bandwidth usage where needed and this would be excellent.
George
At 06:23 PM 2/1/2007 -0600, Piers O'Hanlon wrote:
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<pre wrap="">Hi,
On 01/02/07, Joseph Stone <a class="moz-txt-link-rfc2396E" href="mailto:stone004@umn.edu"><stone004@umn.edu></a> wrote:
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<pre wrap="">We've identified a need to have slow downlink participants be able to send
their video but not receive video. The idea here being that high downlink
bandwidth participants will be able to see everyone who is participating.
It's not enough to just not display the video for slow downers, the bridge
needs to be told not to even send the stream at all. It's enough for them
to be seen and for them to have two way audio (highly compressed - i.e.
GSM).
Is there a current version of vic that will fill the need?
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<pre wrap="">There are a few approaches that we may be able to take:
1) Modify VIC so that it does not join the multicast group - thus it
should only send traffic into the network and not receive any video
traffic from external sources. I'm not sure if this will work (though
it should in theory - We can test it..) but we could add this feature
fairly easily.
2) The following two options depend on having wide deployment of a
newer version of Internet Group Management Protocol (IGMP) - Version
3. Unfortunately I don't believe it is - though it is seeing wider
deployment.
2a) UCL vic has recently included a new feature that allows one to use
Single Source Multicast (SSM) - Which needs to be started using a
slightly different command line. For video reception a separate vic
will need to started for each video stream wished to be received.
2a) VIC could be enhanced to actually take advantage of some new
features - namely source based filtering. which would allow one to
choose which video srcs one wanted to see.
3) Another approach would be to use a special gateway or relay that
allows on to filter/choose the sources recieved - there are a few that
have featured in various AG retreats.
I'd would like to hear if others are interested in such functionality.
Piers.
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<pre wrap="">Joe
On Jan 31, 2007, at 4:25 PM, Sam Gundry wrote:
Hi Socrates,
I actually commented out this line yesterday, before receiving this email.
:)
Video images now display locally in both the consumer and producer windows.
What should that line of code do? I haven't noticed anything out of the
ordinary yet...
Thanks,
Sam
Socrates Varakliotis wrote:
Hi Sam,
I assume you're still building Vic on Windows.
Can you comment out line 562 in tcl/ui-main.tcl and rebuild?
#$target enable_xv $enable_xv"
Let me know what happens then.
Thanks,
--
Socrates.
----- Original Message ----- From: "Sam Gundry" <a class="moz-txt-link-rfc2396E" href="mailto:sgundry@vpac.org"><sgundry@vpac.org></a>
To: <a class="moz-txt-link-rfc2396E" href="mailto:Andrew.Rowley@manchester.ac.uk"><Andrew.Rowley@manchester.ac.uk></a>
Cc: "Piers O'Hanlon" <a class="moz-txt-link-rfc2396E" href="mailto:p.ohanlon@cs.ucl.ac.uk"><p.ohanlon@cs.ucl.ac.uk></a>; <a class="moz-txt-link-rfc2396E" href="mailto:vic@cs.ucl.ac.uk"><vic@cs.ucl.ac.uk></a>;
"sumover-dev" <a class="moz-txt-link-rfc2396E" href="mailto:sumover-dev@cs.ucl.ac.uk"><sumover-dev@cs.ucl.ac.uk></a>; <a class="moz-txt-link-rfc2396E" href="mailto:ag-tech@mcs.anl.gov"><ag-tech@mcs.anl.gov></a>
Sent: Tuesday, January 30, 2007 11:03 PM
Subject: Re: [AG-TECH] Re: Compiling VIC in Visual Studio 8 (2005)
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<pre wrap=""><!---->
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<br>
<pre class="moz-signature" cols="72">--
Bob Riddle (bdr @ umich.edu) Enabling Technologies
University of Michigan Medical School 1301 Catherine Street
M4101 MSB1 - 6024 Ann Arbor, Michigan 48109-0624
"Math illiteracy affects 7 out of every 5 people"
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