Re: [GnomeMeeting-list]Video quality

[Lawrence Manning <lawrence smoothwall org>]

On 30 Oct 2001, Damien Sandras wrote:

> > Cant help with that one, but I dont think so
> CVS contains support to set the jitter buffer delay and limit the
> bandwidth.
> If you increase the jitter buffer for audio, you should not loose audio
> frames.

I will look into compiling the CVS version shortly, then.

I only say about this because my experience of video+audio has been, well,
not very good.  In the test situation, I had my camera turned on, and the
other person did not.  Bear in mind that I am on 64kbit ISDN, and the
other end is an ADSL connection, and we are connecting via a IPSec VPN.
Anyway, audio only is great, no problems at all.  But when I try to send
video, the other party receives some video, but gets only a second or so
of sound every 10 sec or so.  Not good.  So it is nice that there should
be a way to "prioritise" the sound.  BTW, int his test case we are both
using gnomemeeting.

> Updated Blocks permits you to choose the number of blocks (that haven't
>  changed) transmitted with each frame. These blocks fill in the
> background. If you choose to transmit 99 blocks that have not changed
> with each frame, lot of background blocks will be transmitted with each
> frame, and the picture will be more often refreshed.
> So it is the best quality (I think I sent a mail containing an error
> about that).

So my logic WAS right :) What is curious, is that the update blocks isn't
the other way around.  Ie. a count of how many "forground" blocks are sent
per frame.  The forground being the part of the picture that is changing.
Surely if you take the english litterally, blocks that have not changed do
not need to be transmitted?  Ah.. this is confusing :(

Anyway, to me to get the best quality we should be sending as much as
possible of the image per frame.  Is there a way to increase the updated
blocks beyond 99?

Am I right in thinking that the "video quality" setting basically sets the
quality of each video block?  In which case, this setting is working quite
properly as I can see that for a high number, the blocks are not so
defined.

Anyway, I love gnomemeeting :) I am just trying to get some use out of my
rather crap webcam :)

Lawrence Manning

Development Team Leader and Author - SmoothWall - www.smoothwall.org
Email: `formail -z -x From: <thismail`