JVC VCR line TBC, tape still jitters?
 

Hello all, just got a workflow from Lordsmurf (thanks for that) and I've been testing it out, so far so good. Except that vertical jittering is caused on some of the tapes I have. Though the jitter looks to go away when I turn off the line TBC on the VCR

The rest of the setup, so the JVC S-VHS VCR < Kramer FC-400 TBC < Pinnacle 510 Capture Card < VirtualDub running on Windows XP, remains the same.

Two samples are provided below.

Vertical jitter "caused' *not really) by TBC is similar to tearing, and that requires ES10/15 between VCR and frame TBC. In that scenario, VCR is just really really good VCR, line TBC not used on it. ES10/15 performs line duty.

The root cause is missing or incomplete lines. This situation is more rare, and pisses off both JVC and Panasonic VCRs. The JVC line is weaker than Panasonic field, but neither was tuned to be strong/harsh like the ES10/15 type Panasonics.

Some tapes just suck, and no line TBC cannot fix it, not even ES10/15 (or certain other items).

Ah I see then. So using the es10 while the VCR's line TBC is turned off then?

So would the setup go like this?

JVC VCR (Line TBC turned off) > Panasonic ES10 > Kramer TBC > Pinnacle Capture Card (all plugged in using S-video)

And I'm assuming the Panasonic es10 is only for the VCR, so if I use a Sony CCD-TRV87 camcorder for video8 tapes, that will be plugged into the Kramer TBC instead of the es10.

Still, thanks for responding and helping out here. I'll certainly check to see if the es10 makes a positive difference

First line TBC wins.

If chain has 2x line:
- JVC (ON) > ES10/15 (always ON) = ES10/15 does nthing
- JVC (OFF) > ES10/15 (always ON) = ES10/15 performs as strong+crippled line + side effects (posterization, AGC, etc)

Yes, ES10/15 adds problems, but goal is net better video. In your situation, best/ideal/perfection not possible, least worst is possible.

Yes,
JVC VCR > ES10/15 > frame TBC > capture card
Hi8 camera > frame TBC > capture card

When this happens, it tends to mostly affect videos made by lower grade equipment. So no TBCs were in use, transports were not stable, etc.

Ah great, good to know, thanks!

Though after doing some more tests, I realized the jittering happens even with the video8 tapes I have, they only appear on the digitized capture and not on the LCD preview screen the camcorder screen...

Also tried a different VHS tape with the VCR line tbc on and off, didn't make a difference for the single frame jitters.. actually all the tapes I have, include some sort of jitter. Only ones that play perfectly fine are the commercial movie tapes.

I'm trying to see if the problem at hand can be either with the Pinnacle 510 USB, or instead the cheap s-video cables I used. Bought some cables from BlueJeans so I'll check to see if they help with anything.

Make sure your tapes are not second gen dubs, If the jitter is baked in there is nothing you can do, Although I had an experiment where a device removed most of the jitter in a second gen dub, I've read about this technique in white papers where the LTBC tracks the start of each scan line based on the black level, So this device most likely uses this technique. Here is a link to the results, Though I'm not suggesting anything here, those devices are hard to find anyway.

Well, none of the tapes I have look to be second gen dubs, but thanks for replying anyway.

Got the S-Video cables, they didn't fix it sadly...

Though going through, I think I realized that the 1 frame jitter (where the frame jolts upwards) might actually not be jitter from the TBC (though turning it off with certain tapes produces a different kind of jitter) but instead, interlaced jitter. As using the deinterlace filter in VirtualDub to remove the top field and keep the bottom field fixes it, but I have a feeling it wouldn't be best to do that...

Do the ES10/15 method outlined above.

Well after using an ES15, that did the trick and the one frame jitter is gone. Though knowing that it happened even with the JVC (or even Sony camcorder)'s line TBC on and off, I suspect the cause of the problem is actually the Kramer Frame TBC.

Sucks I'll have to deal with the ES15's problems with every tape I use, VCR or Camcorder.. but I suppose using it to prevent jittering is better than not using it at all.

The ES15 still passes errors/ It doesn't only correct errors. So still chase with Kramer in workflow.

VCR > ES15 > TBC > capture card

Yes, ES15 adds some errors, but sometimes this is unavoidable. In fact, I'm dealing with a tape with layman-jitter issues right now too. I still chase the ES15 with my TBC-3000, which does resolve some remainder signal issues from ES15. Neither JVC line nor Panasonic field fixed it, ES15 did.

You have yet to show any evidence of them "passing through" errors. The dvd-recorders from panasonic and others output a stable video signal with any errors from the input that they fail to decode baked in. They can however add copy protection on the output if they sense it on the input which can upset some capture cards but unless you are dealing with that adding a tbc after them is just adding extra signal degradation.

There are members of this forum who have experienced this identical situation. In fact, I recently had a conversation with one, and we discussed the plan of attack in an email/PM. I urged him to post here about it, so others (like yourself) can see. I think he needed time to get samples together. (Note: Tech questions are always encourage on-forum, but that was part of a larger discussion that needed to be private.)

I have samples on a drive, but lack time to prep and post.

While the signal was A>D>A, errors can still pass. Not everything gets baked in, which is why (for example), line TBC can correct nth gen analog. It's not entirely baked in. Yes, that example is analog, but it's the same siutation. Certain analog errors can pass through A>A or A>D>A.

This is all easier to see on nth gen, but it happens on 1st gen.

The frame TBC chasing the ES10/15 is effectively adding a frame TBC like with any workflow. The ES10/15 merely contains strong+crippled line TBC, with non-TBC frame sync. There is enough leeway for errors to wiggle through that signal slolem.

It's not copy protection, but dropped frames issues.

I can't write some things here, read between the lines. But realize TBCs are more than the sum of parts, more than just chips.

Apologies for this rather later response, but I do understand how the frame TBC is still beneficial here and am continuing to use it along with the ES15 for line TBC duties with both VHS and video8 tapes. Did some quick tests without it a while back, VirtualDub did report inserted frames but no dropped frames.

With the frame TBC included, 0 dropped and inserted frames were reported. So the fc-400 is doing it's job on that front.

Drops and inserts are essentially the same thing. An insert is a dupe, while a drop is nothing. The outcome is still missing data. The only difference is that an insert prevent audio sync loss (usually), while the drop ensures loss. It's all a bit more complicated, but that's the brief important takeaway.

As I stated, the ES10/15 is not 100% in correction, and output is still impure, and can still cause drops/inserts. Hence chasing with TBC.

You're doing fine from what I'm reading. :congrats: