[Cin] MKV containers

[Andrea paz]

I attach a video: the first part is made with an mpeg proxy (I have
not seen its GOP), then there are examples without proxy with X11 and
with X11.opengl. The file consists of screen capture with vokoscreen
and gave rise to mp4 files with GOP but at 250. With proxy I am fixed
at 30 fps, in the other cases we speak of very low fps.
@IgorBeg. Thanks for the info. Very clear and informative. If you talk
like Yoda, then I talk like Chewbacca. :-)
@Phyllis. Could you tell me which libraries have been updated lately?
So I can do a search in the Arch linux forum/wiki to see if they are
causing any problems.

https://www.dropbox.com/s/z3na1r3vmwcnn6n/test.webm?dl=0