[AG-TECH] Improving video quality

[John I Quebedeaux Jr]

Jason,

Something to point out - that this is not a real time change if you  
make it via the node manager; it's just a parameter setting that will  
get "read" the next time the service manager reads it to pass to the  
VIC. So, if you make it here - stop the video and restart it so that  
the VIC's will reload with the new settings.

I guess those who know VIC are old hat at this - for those who aren't:

A quick way of testing this: for temporary/testing purposes before  
you go change your configuration in the node manager- If you want to  
see the results in real time and to test what setting is optimal go  
directly to the VIC that is sending/transmitting, choose "MENU" and  
you can find the sliders there for "Rate Control" which is a setting  
to limit the rate that the vic will transmit at (useful for those  
with limited bandwidth) and the frames per second (defaults to 24)  
and then the quality setting further down. Like Jason said, setting  
this too "low" (lower number is better) it will seem worse - check  
the rate again. Keep a close eye on the bandwidth used when you have  
lots of motion. I actually use this to "stress" test when setting up  
a connection. It's fairly easy with just one or two VICs and lots of  
waving (jumping jacks anyone?)  in front of the camera to push  
between 3MB and 6MB (note, the rate limiting is different on Windows  
than it is on Linux) per camera.

So, keep in mind changing the quality setting will change the  
bandwidth utilized - if you have the bandwidth and the system can  
handle it - you may have to raise the "rate" as well so it won't get  
"limited". You might try to see just how low you can set things as  
well for those sites who are bandwidth challenged. I discovered that  
i don't really like going lower than 12fps no matter what the quality  
setting was and that I really didn't like changing the quality to  
anything higher than 10. In some cases, like when we put a camera on  
a screen - i'll lower the FPS to 5 or 10 but change the quality  
setting to 2 - thus getting a very nice look at the screen (well,  
mostly) but not pushing the bandwidth up too high when the slides  
changed.

Finally, i usually like to set my defaults to quality "5" as its  
better - but not so much so that it makes a large hit on bandwidth.  
On the other hand, i have the bandwidth, some of my sites we work  
with don't.... but they will very very soon!

my 25cents..

-John
-- 
John I. Quebedeaux, Jr.; Louisiana State University
Computer Manager LBRN; 131 Life Sciences Bldg.
e-mail: johnq at lsu.edu; web: http://lbrn.lsu.edu
phone: 225-578-0062 / fax: 225-578-2597


On Jul 10, 2006, at 10:32 PM, Jason Bell wrote:

> G'day all
>
> I thought I would you let you all know of a little quality trick  
> that I
> stumbled across that I found improves the video quality noticeably.
>
> If you go into your node management (Works for both AG 2.x and 3.x)  
> and
> configure your video producer services, there is a quality setting  
> which
> defaults to 75.  If you change this setting to 95, I have found it  
> makes
> a significant improvement.  If you set the value to 100, it may  
> make the
> video actually worse and sluggish.
>
> I hope some people find this information useful.
>
> If you have any questions, please don't hesitate to contact me.
>
> Thanks for your time,
> Jason.
>
> --------------------------------------------
>
> Jason Bell, B.I.T.
> B. Info. Tech. (Honours) Student
>
> Network Engineer
> Information Technology Division
> Central Queensland University
>
> High Performance Computing Support Officer
> Central Queensland University
>
> Research Assistant to the Nonlinear
> Intelligent Systems Research Group
> Faculty of Informatics & Communication
> Central Queensland University
>
> E-mail : j.bell at cqu.edu.au
> Phone : 07 4930 9229
>
> --------------------------------------------
>
> Patience is a virtue.
>
> But if I wanted Patience,
> I would have become a Doctor.
>
> --------------------------------------------
>

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