TBC 2MB v. 4MB and TBC jitters?

[DaveS]

Can anyone comment on using a TBC w/ 2MB memory vs. 4?

I am using a JVC DVS3U and due to a model change shipped w/ 2MB for the TBC (vs. old model which seemed to have 4). Can anyone say what the difference in the TBC might be? I am capturing NTSC VHS for passthrough to a canopus advc-100.

Also, in my short test, the VCR w/ TBC turned on seemed to introduce a periodic jitter into the video which is not present in the source. Overall, the picture which I captured using the DVS3U is tons better than my old JVC VCR but I am wondering about the jitter. I plan to try turning off the TBC and also turing off the TBC and turing on the DNR to see how that affects the catpure.

This tape happens to be about 10 yrs old and I did see some improvements in the straightness of images in the vido (e.g. the corners of walls are sharper and straight) which I attribute to the TBC. But, I am also wondering whether this jitter is somehow introduced by the TBC (happens maybe every 5 to 10 seconds - brief (quarter to half second) jitter, almost as if someone shook the camcorder one cycle up and down).

Any comments would be appreciated.

[FOO]

Sounds like Macrovision

[DaveS]

thanks - it's actually a homebrew tape, namely my honeymoon...

the periodic jitter is strange - it bugs me a lot but overall is probaly not the end of the world, although I wouldn't want to give a customer something w/ that jitter in it...

[lordsmurf]

The jitter is due to old source that is degraded. The JVC machines incorporate a mid-grade TBC. It works best at horizontal errors. You should consider a DataVideo TBC-1000 which does well at vertical errors such as the one you see, and synchs frames.

There is no miracle cure for degraded source. Introducing one fix may well start a new problem. You've got to locate the lesser of all evils, with whatever combination of equipment you need.

The JVC machines are top-notch, at least the JVC HRS7900 and HRS9800. I'm not all that sure about your machine. The TBC/DNR is a single function, not a separate one, so no luck trying one without the other.

Be sure to use the full complement of filters allowed to you. The stabilizer is great, but may add vertical jitter if the degradation is present (though unseen to the naked eye). Remember, these devices all see data and signal, not the picture we see. So it may very correct the SIGNAL, but that part of the signal that was corrected may have never been a problem, and in fact now DOES cause visual problems whereas none existed before.

The 4MB version is much, much, much better than the 2MB version, at least when using the TBC/DNR. The RAM is for DNR, not the TBC. It makes a big difference on red/blue-haze artifacts seen on most VHS tapes that are not commercially-made SP.

I whole-heartedly believe your errors wil disappear once you get the DataVideo TBC-1000.

This page has more info on TBCs and the JVC VCRs:
http://www.lordsmurf.com/capture/vcrtbcsuggestions.htm

[Bob W]

Sounds like Macrovision

I agree. I was recording a VHS to DVDR just a few days ago on my E50 and it had the same symptoms so I had to hook up this device to get rid of the macrovision or jitter. http://www.facetvideo.com/

[The village idiot]

Sounds like Macrovision

I agree. I was recording a VHS to DVDR just a few days ago on my E50 and it had the same symptoms so I had to hook up this device to get rid of the macrovision or jitter. http://www.facetvideo.com/

Actually, he already said it was something that he shot with a camera. So it isn't macrovision.

[lordsmurf]

Macrovision does not cause jitter. There are three known levels of Macrovision, progressively worse, and from different eras. Contrast fluctuation is most common. Some cause color to disappear along with contrast errors. Some are tearing of the video itself. Jitter is caused by other things unrelated to Macrovision, though the Macrovision "fixes" (which are just video correction methods meant to restore the video, including artificial errors like Macrovision) may work to correct the problem. Often tapes are just bad, regardless of the Macrovision contained on the tape. Yes, this includes commercial ones. I just got done with a horrible 1989 commercial VHS tape that had never been played before (still sealed after all this time).

[FOO]

I didn't notice he said "up and down"
Macrovision can introduce horizontal jitter but usually
only during vertical retrace where you can't see it.

What triggered my reaction was the 5 second period of the
disturbance -

[DaveS]

thanks a lot for all the replies - they are greatly appreciated...I thought I'd post an update fwiw or for others down the line

I did add a TBC-1000 to the mix and then tried a number of combinations of turning on/off the features in the JVC VCR...

..so far, the best combination for reducing the jitters (on tape, mine are a different story!) has been turing on the JVC stabilizer filter (which turns off the JVC TBC/DNR) and running that with the TBC-1000 (and, running the video mode in the VCR on soft to cut down on the noise a little since the DNR isn't on - I think a gaussian blur s/w filter may have a similar effect but adding the softness as an analog h/w filter (is it?) closer to the source seemed more appealing).

the jitters are not gone by any means but they are cut back quite a bit and not nearly so noticable...the tape seems to have degraded quite a bit in 10 yrs. even without viewing (although it is a second generation copy which was originally recorded vhsc EP, for which I am really kicking myself);

I'm sure I'll find some ways to fool w/ this some more & will post for anyone who's interested

lordsmurf...I liked your guide on editing / TBC...thanks...I like B&H photo as well...not sure if you've ever been to the store - it's possible to spend a lot of time in there if you want (and as much money as a small country would have)

[zanos]

Actually not viewing a tape for that long will likely cause problems for it. You sometimes just have to break these things out every now and then and view them. It's not a solution but it's better than not doing it.

[vhelp]

Hi guys.

Not to throw in a screw or anything into the topic, but have you also tried
other options or ideas besides what you're currently doing ??

@ DaveS..
You might want to post a few pics on your issues detailing what you are describing
here. Cause, it could turn out to be something very completely different, or
it could introduce other ideas into the pot here Anyways..

I've learned that you sometimes have to pull all stops, even if that means
doing a few crazy things.

What I'm on about, is for instance...
* Trying out a complete different VCR, and preferably w/out NR or other Filterng
...and TBC built-in gizmos and whatnots
* or, how about giving an Analog Capture card a try instead.

I've found my ATI-TV Wonder (ATW) card to do wonders for VHS, even stops those
annoying wiggles that I got when I would mix a number of items either together
or not ie, my TBC-100 (not 1000) and DC10+ card and combo of the two. Yes, adding
two TBC's (or sync devices) can actaully enhance or magnify the issues further or
complicate by adding other forms of issues
But, the only major problem I have w/ the ATW card is the fact that it incorporates
nose into my captures.. (due to other issues I'll leave out here)
So, in all my trials and tributes, I've learned that other outside sources can
introduce issues into your final sources.

But, I'm surprised that you are getting some distortions in your final captures
w/ your ADVC-100. Cause, when I use mine on VHS sources, they rae always pretty
clean w/out sync and wobble/wiggles etc.

I think you should try another "regular" VCR.. one w/out TBC and just run your
ADVC-100 through it instead.. if anything, to just see if you get the same issues
in your original post.

Do give the above some salt for thought
-vhelp

[DaveS]

thanks again for everyone's suggestions - I just wanted to post a few related things re all of the above.

- I would have posted some sample frames, but I had deleted the avi with the best (e.g. worst jitter) examples. With the reductions in jitter form the JVC fileter, I still had some. Rather than posting them, I will just say that a jittered frame looks exactly the same as a good frame, just offset vertically by a bit; otherwise,no distortion or artifacts - just a bit higher, then the next frame returns to the way the majority of the others are

- Re the JVC VCR's I spent a bit of time on the phone w/ JVC customer support (consumer, who knew very little, and pro, which was very helpful). There are two current and very similar decks, the prosumer HR-DVS3U (which I have) and the pro version the SR-VS30U. Interestingly, these both have 2m of memory for the DNR (the literature isn't consistent, but the pro support guy did some research to confirm this). Yet, the pro (and prosumer) models both have the 'full complement' of DNR available in them (e.g. the 3D filters, etc.). So, what I wonder is whether in the newer models, they have found a way to deliver the DNR which used to take 4M now with only 2M. If the pro model did have the 4m and the other only had 2, and this cut out some of the DNR features, I probably would have gone w/ the pro model (about $125 more). However, in this area, according to the support, these two models are the same. Fwiw, the areas they differ are in warranty length (90 days v. 1 yr), recording from two different sources at once onto the DV and VHS decks (pro model can, prosumer model can't), and DVCAM (Sony) support in reading DV tapes (pro model can, looks like prosumer model can't?).

- Lordsmurf - I really appreciated your guides - I wonder if JVC has made a change in how the do DNR based on what I found out. I especially pursued the info. on memory in the two different models based on your posts / guide, but by all appearances, the 2m current models seem to offer the fulll complement of DNR. I could be wrong, but this is what it seems to me. The JVC site does have specs on the two machines.

Again, thanks a lot for all your help - you guys are excellent.