It looks like something from the bad old days of analog. I think it was called "line tearing". I'm not too familiar with all the details from way back then but I think it had something to do with the horizontal sync pulses or the horizontal frequency being off. Each line gets more and more out of sync and then gets pulled back into sync. No doubt some other old foggy who was working with analog gear back then could explain it better than me.
On the other hand if this was from something all digital I'm at a bit of a loss. There is an issue with scaling interlaced video but it does not produce that kind of artifact.