slow videomixer element

[Nicolas Dufresne]

Le vendredi 30 mai 2014 à 17:17 +0200, Dušan Poizl a écrit :
> Hello. I have pipeline which capture video and encoding it with x264. 
> Now I want add functionality like adding usb video camera or static 
> image overlay. So I tried adding videomixer element. But even adding 
> simple pass through videomixer element increase CPU load from 20% to 
> like 50%.

Yes, videomixer is expensive in CPU processing. Though, it could be
improved, with enough time. I have filed a bug, suggested patches (not
yet correct) and potential changes toward this, but didn't have enough
time:

https://bugzilla.gnome.org/show_bug.cgi?id=701095

Please provide more details if you'd like some help in actually
improving you situation. There is most likely few things that you can do
before changing videomixer code. (e.g. background=black gives direct
gain on performance, by default it always draw a checker and compose on
top of it, a simple black clear is cheaper).

cheers,
Nicolas