TBC for the desperate?
 

At the risk of being verbally pummeled, ostracized, and cancelled...
I see this linked site which has numerous video standards converters, many which mention TBC.
With true TBCs now at $2000 and up, is there anything at this linked site that might be helpful, or a magic bullet to members who need to step up the quality of their captures...?
I particularly target the SD devices, not HD.
https://www.worldwidevoltage.com/video-converters.html

No.
Avoid.

I saw that years ago, and had curt semi-rude conversations with that company.

What exists there now is
(1) bad HD converters
(2) bad SD converters
(3) at best, flawed Cypress chipsets in late model items (and even the early models had quirks, such as PAL good, NTSC sucks)

The good devices have been gone for more than a decade.

For whatever dumb reason ("SEO" most likely), they have ghost listings. Most are hidden from the index you linked, found only with Google, but not all. Some of those products haven't been available in years.

That company also has multiple aliases, several store fronts. The main name is SamStores. It's one of those very shady photo/video stores, like the NYC operations of yesteryear. Reviews have always been bad, and the reviewers had very legit complaints. Also beware of reviews from sites that are gamed, like SiteJabber or TrustPilot, all of which have reviews that are only 1-2 years old. But this company has been around since at least the late 90s.

Nothing actually available there is a TBC, or even TBC-like.

Fair enough.

In addition to what LS said, most devices in this age are not even available. You see the prices + buy now button, but if you buy they will cancel your order/won't ship. If you contact them, they will tell you these are not available.

Just like svideo.com that has an AVT tbc, but are too lazy to remove it and they only tell you after you pay even though it's been out of stock for years. (maybe it brings them a lot of views?)

I have checked all desperate ways in several countries (and in different languages). If there is a TBC for the desperate you would be seeing something in the marketplace.

IMO a standards converter is just that. It likely will provide a very stable time base in its output video stream, but in the process may well bake in time base errors in its input. And it may give you an output in a signal format you do not want not to mention any standards conversion artifacts.

That is not to say you would not find some devices give some benefit with some video inputs, but it they should not be counted on to be useful over a wide range of sources. Further high quality video converters such as used in broadcast and video production studios may expect a solid input signal with no time base errors.

Yes, all correct, that and more.

For example, most converters that actually do have TBCs disengage on "passthrough" (PAL>PAL, NTSC>NTSC). The TBC is after the formats conversion chip. So worthless. The conversion is horrible crap quality, what we did in the early/mid 90s before digital anything existed.

The few exceptions that did exist, hidden TBCs in converters, are pretty rare. But a reason I don't give out those brand/models is because the units vary highly. You're more likely to get an expensive horse (with a baton glued to its head) than a unicorn.

Might works if the video was a kids birthday party :laugh2:

-- merged --

For the Desperate: On a more serious note, video mixers such as the Videonics MX-1 and MX-Pro contain a frame synchronizer that is used to sync two independent video streams. It can provide infinite window TBC-like functions and can help with some video if timing issues are not too bad.

It is not the same as a dedicated competent TBC, but they do help some video issues and can strip Macrovision, and they sell on the used market for a lot less than a dedicated TBC. It can be set to duplicate/drop fields if needed to maintain a precise frame rate, which may help keep audio in sync. Your friendly neighborhood wedding videographer (if he dates to the analog video days) might even have one on a shelf they no longer use.

Panasonic and others offered similar products.

Yes some they do work well like the Videonics MX-1:

https://youtu.be/HEXLlqJQ7Oc

https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15

Working MX-1 appear to be going for around US$150 plus shipping. A bit over a year ago they were perhaps 35% lower.

FWIW internally the MX-1 is 8-bit, 4:2:2, with luma sampled at 13.5 mHz and RS-170A compliant. It has 4 input channels, s-video or composite, and stereo audio. Bandwidth is 5 MHz, (nominally 400 lines).

The follow-on MX-Pro was designed toward DV signal standards and used 10-bit for s-video input quantization. It also included some basic proc amp functions.

As with all used gear the trick is to find one that is in good working order. A fair number on ebay are listed as parts only.

MX-1, etc, are a class of "also has TBC" devices. But remember, TBC is a wide term that can mean almost anything, and sadly often does. It's why a Canopus ADVC "has a TBC" (BS!). The MX-1 has something, but there are caveats to its use, and it's weaker. So while it can work, the tapes must be pristine 1st gen from a camcorder. Not -C, copies, retails, etc. Some larger % of those will fail, whereas actual TBCs will not.

It's a TBC(ish). Those are budget options.

Ironically, the more "desperate" a person gets, the more I find it's simply another case of being too overly cheap about conversion.

And as stated, the horrendous condition of most of these non-consumer pro/studio items. While your average chain-smoking trailer dweller took zero care with gear (Walmarts VCRs, etc), the same was true of employees in studios (ie, not their stuff, who cares?), or students (either "not my stuff" or "duh"). It was always the somewhat more sophisticated tech-savvy or art-savvy hobbyists, DIYers, videographers, or small time studios that took care of this gear. Many are still holding. Some thankfully so (current costs), others have cashed in (ie, the main reason we still get a trickle of non-crap devices).

That's just the blunt reality of the situation. :(

Students aren't really that bad/careless :depressed:

Students in the 80s/90s/00s are what I refer to here. Whether or not modern 10s/20s students are that haphazard with tech toys may be different, or not. My gut feeling would suggest more techno care from the current young adult generation. Modern 16-22 probably understands tech costs far better these days, with their expensive cell/mobile phones and tablets. We didn't carry that sort of stuff when I was younger. At most, we had a fancy watch. Different world.

The MX-1 from the 12voltvids did a great job, The guy literally stalls the video head by hand and banged on the VCR and in both instances it produced rock solid picture, This test proved the MX-1 is among the best TBC's out there, I want to see an expensive TBC achieve that.

Probably not your average defective black AVT, but maybe other good models can.

Just tried with one of my For.A units, it does a good job. Of course, it's hardly a calibrated test method, but it does show that a lot of these units do more than many credit them for.

Of course my For.A is designed for 'clean' professional sources :rolleyes:

We've been over this before.
- PAL sources tend to do a wee bit better than NTSC
- your (client's) sources are probably cleaner than average, being mostly camcorder home movie masters, BBC sources, etc.

Add those together, and you have a slight advantage here.
But it's also a % dumb luck.
Not to mention the condition of those old boxes is so ungodly variable, more bad than not.

I know that some people can get by with certain TBCs and TBC'ish type setup, due to several factors. That's why I often ask so many questions about a project, from sources to destination.

But the fact is this is not a 100% consistent repeatable process when you get "in the weeds" of TBCs and sorta-kinda TBCs ("TBCs", TBCish). So you're an exception to the rule. Awesome! But an exception to the rule doesn't overrule the rule.

The For.A models are designed for clean sources. I can make For.A units crash on sources, and it's one of the easier brands to do that to. (Kramer is super easy.) I have a harder time getting such consistency from flawed back AVT-8710 chipsets.

I guess I've just been doing this longer than you, with a much larger source experience (and test/dev library).

If I come across an MX-1, I'll test it again. Sometimes per-unit variables do skew tests, especially with less tests performed. But the fact that there are variables is a vector for performance. It's one of the main ways how I've been able to identify so many production changes in products.

So
- Suggesting MX-1, For.A, etc is a "good TBC"? No.
- Suggesting those could be an option, but there are variables and unknowns? Sure.

Now we're getting back to the thread topic: truly desperate for a TBC. Looking outside of the list of known-safe models (with widest compatibility for sources), crossing fingers, gambling bucks, that a unit might work. But those won't necessarily be any cheaper, and then "buy it, use it, resell it" advice may not work on those. Penny wise, pound foolish.

Anybody reading this just needs to heed all this advice, proceed with caution. I don't want you to blow money on crap, and then be worse off than you started.

Would you care to post some stress tests for the community? It will be much appreciated.

Care? yes.
Have time? hardly. at least not this weekend, maybe next week...
What kind of "stress test"? intentionally messing up the tape? hammering the VCR head like the guy in the video (something I don't trust myself to do lol)?

I don't think he hammered the head, and he used a crappy VCR anyway, he is a qualified Sony technician for VCR's and camcorders, he did this for a living for decades, I don't think you or I have the right to criticize his work. But if you can do any test that can mess up the VBI signal just to see how your preferred TBC copes with it than we can have some data to go by, Price of the TBC is not an indication of it's effectiveness, tests like this are.

Okay, maybe not "hammering" but more like "hitting", my choice of words was not perfect.
I did not criticize his work, nor claimed being more knowledgeable, I clearly stated my limits when I said "which I don't trust myself to do". I do have a crappy VCR that might work for that, it is stored somewhere in a box in my closet, I need to unpack it...

Also doing something for a living for decades does not make you an expert. I have seen a lot of businesses doing things for years, yet they do it badly. It is just that people did not notice, they don't know it is bad, accept because it is cheap, or do not know better alternatives. (not saying this is the case for this guy here, just saying doing for decades =/= not necessarily good at it)

+1 for the part about price. Tests like this might reveal interesting things about the performance, but I don't think they are enough to give a conclusion. Some other tests might be needed imho (really my opinion, not based on knowledge).

That's all there is to it, a frame TBC should be transparent it should not do anything else other than taking that black wavy vertical stripe and turn it into a perfectly straight line, So this test is all that is needed. Note that the MX-1 has two TBC levels, One is consumer level that makes the VBI bar just good enough for a stable picture which you see in all consumer level TBC's and the other is broadcast standard (FCC standard as he called it) that turns the VBI into a perfectly straight line, Which I didn't know it could be achieved on a device like that until I watched that video, I've seen this feature so far on only pro devices such as the S&W TBS800 I have which I posted test captures over at VH.

It boils down to picking the right tool for the job.

There are a lot of different types of hammers. I wouldn't use a framing hammer for trim work, or a tack hammer for framing construction.

I think the point is that the favored (on this site anyway) TBCs tend to do well with the broad range of typical VHS signal garbage. Other products may or may not cope with the same range of issues. If a product work for one's case to one's satisfaction, that is what matters. It may be appropriate to have several variations of a tool in the tool kit.

I've been following this thread (as I do most just to learn) and I've decided to speak up on this overall subject.

I would very much like to see a list of the specific problems that frame TBCs fix and then an accompanying list of which of these problems specific TBCs and "TBCish's" fix or don't fix. Lots of vague pros and cons are thrown around and all but a very limited number of TBC's are pooh-poohed as useless or praised as a godsend. But there is rarely any real explanation of why. From my perspective, terms like "weak", "strong" or "crippled" don't mean anything without definition.

My perception is that some TBCish devices (by that I include all possible TBC candidates) are "robust" and work to rebuild a reliable frame signal for almost any crap signal they are sent. Other TBCish devices are not that robust but still might do enough to get the job done for many but not all tapes (some DVD recorders for example). For many of us, many (or most) tapes might be adequate. For others not. Certainly for anyone that makes a living (or even side income) doing captures for others, robustness under all conditions would seem essential. There also seem to be significant differences between NTSC and PAL options, both for better and worse.

A specific function that I believe a "robust" (strong?) TBC will do is to ignore Macrovision and rebuild a solid frame signal when sent an intentionally bad one (Macrovision). If you are trying to digitize a library of commercial tapes this would be essential. If you are digitizing a bunch of home videos maybe it is not essential, though desirable. I have a number of devices that simply refuse to pass (or record) a Macrovision signal. When they sense it, they just give an error message or shut down the signal. For instance, my DV camcorders record for a instant and then stop recording and put the error message on screen. I've used this "feature" to test the Macrovision "passability" of a few TBCish devices. I have a few that will defeat the Macrovision and others (that I know have a "frame synch" function) but won't pass a Macrovision signal (e.g. Panasonic AG-MX70). It's fun to play with the "transitions" on the MX-70 to test when it decides it's seeing enough of the Macro signal to shut down the output. It won't let much through... But my bet is that it will correct weak frame signals as long as they are not so weak as to be perceived as Macrovision (false Macrovision?). We'll see. BTW, you don't want an MX-70 unless you have a very large space to put it. It's a monster...

So can we get some definition of what makes a good TBC? My gut tells me that they are actually much like capture devices and VCR's: they vary from bad, to OK, to good, to better and finally best. And Like VCR's, condition will be crucial as well.

BW

PS: Like Barry, I'm now taking cover :eek:

Very legitimate questions deserve honest answers, While I cannot answer all of them let me make a distinction between frame time base correction and Microvision removal.

A frame TBC's main function as I described above is to take the VBI signal and re-align it to an internal clock reference producing a clean signal for the device down stream to lock on, this type of time base correction is found in any TBC as well as old school TV's, In addition frame TBC's have a digital frame store, so besides fixing the sync signal it actually store the whole frame or a field into a volatile memory by digitizing it first and letting it go at a steady pace so that you would have a perfect and clean video. There is another type called frame synchronization that actually takes the stored frames and the digitized audio and time them together into one signal, this feature cannot be found in TBC's that has video inputs only like the AVTool and TBC1000.

A Macrovision removal is another feature the TBC can or cannot/may not have based on the design at the time and the jurisdictions where it's sold or made and their laws, Once you look into how MV works you will notice that it has nothing to do with VBI or frame timing, It is a form of gain control manipulation. Unlike modern VCR's and capture cards, TV's and old VCR's and devices that ignore or has the MV removal capability don't get their gain control calibration from the infected section of the VBI, They either generate their own levels or get the calibration levels from different sections of the VBI section that sits on the top of the frame, I don't know exactly the specific designs but I know there are many and results may differ from one design to another, They were never released to the public as far as I know.

Another great function of a TBC that rarely get mentioned is the chroma sync, The chroma burst signal that follows the HBI signal on every scan line can lead to chroma shift or artifacts if the signal is weak, both line TBC and frame TBC can fix certain types of chroma artifacts, for instance line TBC can address chroma shift, frame TBC can address green and pink chroma stripe on top of the frame.

This is a really complicated subject and not a lot of old school engineers are around to expand on it, We can only judge by experimenting ourselves and see what works and what doesn't

"Macrovision removal" isn't a thing. For starters, Macrovision is merely one brand of anti-copy, and multiples existed. Furthermore, Macrovision branded anti-copy had multiple versions and variations over the years. Anti-copy is nothing more than the injection of artificial video errors into a signal, and really has no place in a TBC conversation. Simply realize that the artificial junk signal is corrected and/or effectively removed from proper TBC, as is a natural error.

But also realize this applies to TBCs that are designed for chaotic consumer sources, not units designed for cleaner sources. Those usually-"pro" units actually filter on less signal vectors, and/or in a weaker manner. This is why any old "TBC" isn't a useful TBC for our consumer analog video capture needs. The same applies to TBCs (or "TBCs" aka not really) built into other items, the "also does TBC" type function found in mixers/etc. Those TBC functions existed not to clean the tape signal, but merely to assist the unit with its internal operations. This is an important distinction to make, as it almost always affects the power/weakness of those units. It's why, for example, DataVideo DVK chroma keyers aren't really TBCs. The TBC function is buried within the other internal operations, and was only made strong enough for those operations. Imperfect input sources easily trip it up, which is why a Panasonic DVD recorder should be used as a pre-filter (and the ES10/15 itself has shaky frame/signal output, even if strongly line corrected).

I have some very telling examples of all this, but it's currently being curated.

Frame TBCs really do nothing for chroma. Not shift/bleed, not cNR -- I wish! Bad chroma has always been a pet peeve. I hate an image that looks like it was infested by a red/blue swam of bugs. Chroma fixes are largely a byproduct of line TBC, and it's further pushed more effective due to digital NR (DNR) in S-VHS VCRs.

It is a complex topic.

Are you absolutely certain you want to nail down that domestic video (designed to be replayed without a TBC) is 'more chaotic' than professional analogue formats?

How much work have you done with UMatic and C?

While U-matic is probably as dirty a sources as VHS, being from the 1970s, it's not the same. And it's why I specifically type "consumer analog sources", meaning not U-matic, which was a broadcaster format. Different issues to contend with. Several members here are more versed in U-matic than both you and I (even adding up our knowledge and experiences).

Remember, this site is used by professionals of all ilk. Quite a few TV station employees here, Apple employees (iTunes), retired broadcast engineers, etc. Many choose to read, not post, but we PM and email. Remember, I worked for studios before health sidelined me some years ago. Lots of filmmakers, actors, etc. While this site has a good posting community, the non-posting community is impressive. I've seen some names (verifiable, it's them) that make me halt what I'm doing, and say "whoa".

High-level discussions (like TBCs) happen on the backend, too, not just the posting frontend. Though I do all I can do encourage posting, sometimes requiring it for me to answer questions. There's been a few times where somebody important was treated a wee bit harsh by a regular member, and it made me cringe, had to apologize for the regular more than once ("he means well, good info, he may have had a bad day").

Always keep this in mind. You're being watched, even if you don't know it. The entire reason I worked for studio is because I was headhunted,

Chroma does have timing, It doesn't just stick to the luma like a magnet, it has to be timed precisely, TBC's process both chroma and luma timing. Yes DNR's function is to clean the chroma stains but those are visual artifacts not part of the chroma timing signal.