Maybe this tip can help.
Load the file /etc/pulse/default.pa in a editor and change the row.
And then start the system new
On the screen we see no Flickering, tearing, artefacts, but after the screencasting we play the Video and it is full of Flickering, tearing, artefacts.
It's nice? No. Can we help? I hope.
The most Desktop come with a Compositer for Eye-Candy animation, i love it.
But good for screencasting? Look at the upper image.
One way is to disable compositing, but not for me, see the next image and i can continue to use under Plasma5 my lovely Eye-Candys.
For NVidia cards that can be a solution.