I have a new NUC with Kodi setup for the bedroom and have been wrestling with this issue for a month or more.
I have TVheadend setup on my main Kodi box in another room. Watching some channels on the remote system generates high CPU usage, enough to cause video to lag behind the audio , stuttering and pixelation. Other channels play just fine. Everything seems to work fine on the main box playing locally, on my windows desktop running kodi, my old Moto G android and streaming to vlc or potplayer.
Below are 2 screenshots one is a channel that plays fine, the other a bad channel. (The Overlay made the CPU jump some on the good channel)
Bad
http://s15.postimg.org/ke3c53b7f/screenshot003.png
Good
http://s15.postimg.org/wh8nsnm9n/screenshot002.png
Here's a full log while watching a bad channel - http://pastebin.com/6J6BDU38
One thing I noticed on the bad channel is that the buffer seems to fill up to 99% then there's a momentary stuttering and the video catches up with the audio and begins to slowly go out of sync again before repeating the process.
Some things I've tried -
Upgraded downgraded to every version of kodi/pvr.hts i could find.
Used OpenELEC, many versions.
The systems are gigabit connected so I'm sure its not a bandwidth issue.
Any ideas where to start troubleshooting this issue?