Re: [Ekiga-list] Bad video quality / bandwidth

[Morris Beverly <morrisb avpresentations com>]

Hi,

I can offer a few suggestions regarding bandwidth and video quality in 
general, as related to your supervisor's expectations.

First, I'm pretty sure that the bandwidth restriction you're talking 
about in Ekiga is shown in kiloBytes/sec, not kiloBits/sec.  This was 
very confusing to me also when I started with Gnomemeeting several years 
ago.  I would prefer to see it in bits rather than bytes myself.

Thus the restriction is actually 1 megabit.  Remember that this is only 
one side of the conversation, the upstream side.  If the other side is 
also sending at 1 mbit, then you are at a total bandwidth of 2 mbits.  
In other words, even a T1 dedicated totally to videoconferencing and 
connected directly to the backbone, would be inadequate for you.

On the quality issue, I use both GM, oops, Ekiga, and several high end 
(on the order of $10K each) Polycom video systems.  The Polycoms are 
certainly higher quality video than Ekiga - they use dedicated hardware 
and proprietary encoding (and lots of $$$).  However the best quality 
that I have ever seen was VHS quality (maybe 320 x 240 resolution).  The 
catch is that this was using ISDN lines (3 of them, in fact).  I do a 
regular video conferencing setup using IP rather than ISDN for an 
extremely, extremely large content delivery company at their main data 
center, directly over their NOC.  When using a full T1 line, dedicated 
to the Polycom (running in IP mode), the quality is, at best, 3rd or 4th 
generation VHS quality.  In other words, pretty crappy.  I can guarantee 
you that you won't get better quality than this.  On the other hand, I'm 
a video guy, so my idea of crappy may be someone else's idea of OK.

You will not get anything better than 320x240 video quality using h.232, 
especially over IP,  no matter what anyone tells you.  There is just too 
much data in a video call.  If you need more, you will need to go to 
some sort of streaming protocol, using independant servers and clients 
at each end.

Now for some useful info ;)

You will probably see a marked improvement in quality by _reducing_ your 
bandwidth request.  Try something on the order of 20 - 50 kB in Ekiga's 
settings and using a small image size, or some variation of the above.  
Once you have established something that works as a baseline, you and 
your associate at the other end can try changing things -- slowly, and 
one thing at a time.

As for projecting the image, once again do the counter-intuitive thing.  
Set your computer to run at 640x480 resolution.   The video window will 
be a larger part of the overal desktop and when projected will not look 
as blocky.  This works only because the projector manufacturer has spent 
a lot of resources on optimising the resizing hardware inside the 
projector itself.  The projector does the resizing entirely in hardware 
and will do a far better job than any PC can do.

Finally, let me say that people in general ( and especially supervisors) 
have wildly inflated ideas about what is possible in video 
conferencing.  If you are only doing your video one way, there are much 
better solutions.  However, if it has to be two way, you'll have to 
realign your expectations.

If you want to go over more detail on this, you can email me at 
morrisb avpresentations com

good luck,

morris


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On 8/8/06, Asfand Yar Qazi <ayqazi gmail com> wrote:

On getting a reply from my supervisor, it appears that the quality

between two ekiga clients isn't satisfactory either.  We're trying to
do video conferencing just to let you know, and we have pretty large
screens on both sides - that's why he thinks the video quality is so
bad - it's all blocky.

The web cam supports 640x480, and the supervisor wants that at least -
he's planning on getting higher video cameras to increase the
resolution when this setup proves that video conferencing works.  Is
there a way to do increase the resolution/bandwidth, we don't have to
use SIP is that's what's restricting the quality.

Another thing:  why does ekiga limit the video bandwidth to 100Kb/s?
I'd like it increased to 1MB/s is possible - the network between our
offices supports that.

Thanks

******************************************************************

--

Morris Beverly
AV Presentations
http://www.avpresentations.com