For those who are interested and the French who don't learn anything at school but make the effort to adapt, here is what I wanted to say:
Problem I put everything on a RPI2 and it's too slow... while tvheadend alone works well.
On an ubuntu VM my image jerks in plex and in tvheadend it's impossible to watch .... I don't know how to do it. I have a sheildtv but the porting doesn't excite me anymore ....