VHS purple horizontal lines at top

[Acidis]

I am fairly new to capturing and encoding videos. I searched the forums but cannot find the correct term to describe the problem I have on the tape.

The closest I came up with was rainbows and chroma shifting. Both don't seem to be what my problem is.

Throughout the tape I see purplish horizontal lines moving vertically at the top 1/8th of the tape. They also seem to become taller and shorter.

What is this artifact called? If I understand this correctly, raindows are artifacts around edges of objects and chroma shift is similar to my problem but static.

If you understand what the problem I describe is, what are the ways to fix it? Are there any filters available to correct it?

Thank you.

[Acidis]

Anyone got anything to say on the subject? Maybe someone knows what this artifact is called so I can do some better searching?

[2ZOD.COM]

Chroma shifting is when colors of objects are shifted one way or the other. It seems like with your problem where the discoloration is only on the top 1/8 of the picture is probably because the tape has degraded. Is it an older tape? That's the only thing I can think of, but I'm still kind of new to this myself.

[fccHandler]

There is a phenomenon called "flagging," in which the top 1/8 (or so) of the tape looks warped, bent, or stretched diagonally. I see this a lot with worn or cheap tapes. Sometimes instead of flagging, I'll see intermittent green or purple splashes of color on the top 1/8 of an old tape. I don't know if there's a technical term for that.

I have heard that a Time Base Corrector (TBC) can fix these things, but I've never had the courage to purchase one. (They ain't cheap.)

[Acidis]

Well, the tape is not mine, so I don't know the history of it. It's not a commercial tape though. It's a copy.

I am curious to find out how to fix it though. I may have to buy TBC for another tape I am having problems capturing and will see if it corrects this problem as well (If I buy it.)