Had this problem a while now, using kszaq's build, 22.214.171.124 temp sensor disabled version at the moment.
Playback is flawless normally but sometimes when I fast forward a tv show that is recorded I get below stuttering.
The only was to fix it is to restart the box.
Audio carries on behind it as normal, even stopping the video and restarting results in the same. it didn't happen this time in the video but normally even if I stopped the video and go and start a movie, the same stuttering happens. with the movies audio in the background.
Im using TVheadend version 4.2 on a linux server, ive tried wiping the box and starting again and even removed tvheadend and starting from scratch with that again.
Ive attached the video below to show what I mean.