[Leopold]

When tuning to 1080i50 tvchannel I get the following errors in tvheadend log.
I think this could cause my artefacts:

http://pastebin.com/5JMMbf73

You said you get artefacts when advanced deinterlace is enabled.
You said you get artefacts from recordings.

So concentrate on the recordings.
Do the artefacts in recording appear only when advanced deinterlace is enabled?
If so then tvheadend is not to blame.
If a recording always has artefacts regardless of deinterlace settings then the problem is in the file (and is likely due to tvheader/tuner backend).

On tvheadend forum I was told, I could suffer from an usb bandwidth issue, as my artefacts and continuity errors only appear when watching high bandwidth hd channels.
Is there a way to check this out or is the rpi 2 bandwidth too low for watching hd livetv when backend on same pi?

I used to get artefacts quite often when watching live tv or recordings with tvheadend, sometimes almost the whole picture would turn green for a second. I switched to VDR because of timeshift problems, and since then I have not noticed any artefacts with live tv.