Jagged lines on edge of objects?

[LeoH]

I'm making good progress cleaning up an old vid, but one thing that is confusing me are these jagged lines appearing on edges of objects. This is film source material and it doesn't look like regular interlacing to me, but maybe it has something to do with that. Can anyone tell me what this is caused by and the right approach to correcting it? Thanks very much!!

Leo :)

http://s90519770.onlinehome.us/cap.png

[Guest]

Post a link to a short unprocessed source clip.

[LeoH]

OK here's a 3 second clip before any processing was done:

Short clip (21MB) (http://s90519770.onlinehome.us/Test1short.avi)

(made with Huffyuv 2.1.1)

Thanks for taking a look!

Leo:)

[rfmmars]

LeoH.......You asked me that question before and I should have responded better. It is called the waterfall effect. Its caused by tape stretch and the rotating head assembly in the VCR. Better machines have less of this.

I have have a post about writing a filter to correct this, but it seem not to be possible.

It also be line pairing since I can only see it in the lighter areas.

richard

[Guest]

You have 25 fps progressive material. There is no phase shift so field matching was not required, at least for the short clip you provided. But due either to crappy broadcast material, a crappy VCR, or a crappy capture card, your second fields are not exact images of the pictures for the first fields. There is color shifting and spatial distortion. I have seen this before. You can see it by separating fields and stepping through in VirtualDub.

The cure is a good intra-frame deinterlacer. For example, you could use:

FieldDeinterlace()

I wouldn't try to nuke the faint interlacing in the sky and flat areas; otherwise you risk killing your good progressive detail. Just do enough to clean up the sharp edges.

[LeoH]

Thanks for the help guys! The PAL VHS source tape was commercially released about 17 years ago, so it's got some age to it obviously. But I captured it using a brand new JVC HR-S5980AJ VCR along with a new ADVC-100 which I thought would give me pretty good results. Do you think the tape has just degraded over the years?

Thanks for the advice Donald, I'll give FieldDeinterlace a shot and see what it does. Do you think the default settings are fine?

Leo :)

[Guest]

Originally posted by LeoH
Do you think the default settings are fine? Yes.

[LeoH]

Well I'm embarrassed to admit this, but I've just had a "D'oh!" moment. I was reviewing my entire capture chain to pinpoint where these jagged edges were coming from and I realized that I'd inadvertantly saved the project in Vegas (where I'd done my initial editing of the piece) as a PAL interlaced project instead of progressive! Problem solved! Anyway, thanks again for the advice - though in the end the problem was caused by my own oversight.

Leo:)