Re: [GnomeMeeting-list]Video quality

["Roger Hardiman" <roger cs strath ac uk>]

Hi,

> I'm not sure that increasing the number of background blocks transmitted
with each
> frame will give you a better quality.

The background block system is there to cope with network loss and
corruption.
When you send video, you do not know if it arrived at the far end.

Suppose something moved, and the packet with that motion was lost. The
remote
user will not see a change.
If this objcet never moves again, the remote user will never see the object
in its true
location.
In addition, when the codec uses Motion Compensation (moving blocks of
pixels about)
it will move the wrong pixels and the image then starts to look really bad.

So the background block makes sure that all the blocks get refreshed once in
a while.


roger