are built-in TBC/noise reduction really TBC?

[spiritgumm]

Toshiba dr4, and I see an RCA model, described as having a TBC. Are these really TBC's or something similar? Also is the Panasonic "noise reduction" circuitry the same thing? I"ve tried the Toshiba and a Panny and had signal problems from vhs tapes which I would think a TBC would clean up.

[lordsmurf]

No, they are not really TBCs. It's complete bullshit that they are allowed to put that on their documenation.

At best, most of them are "TBC-like" filter systems.

The problem is there is not any sort of authoritative measures that requires something contain certain functions to be labeled as a "TBC". So you get the marketing ******** playing around with words that they very likely don't even remotely comprehend.

Stupid consumers don't know any better or care. More knowledgeable consumers get confused. And the more advanced consumers can smell the stink of bullshit from 100 yards away.

[jagabo]

VCRs with TBCs have line TBCs. These correct horizontal sync errors resulting from slight variations in drum rotation speed. This most obvious result of this is to make vertical lines straight rather than wavey (this is a big killer for MPEG compression). Line TBCs can't fix the loss of vertical sync from badly damaged tapes. The result with most video capture devices is a loss of sync between the video and audio. See this post:

https://forum.videohelp.com/viewtopic.php?p=1438915#1438915

Stand alone TBCs are usually full frame TBCs. These capture full frames of video and output a constant, time base corrected, stream of fields. They continue to output a clean signal even on loss of vertical sync (repeating the last good frame in order to maintain a constant signal). This helps prevent loss of A/V sync. Full frame TBCs may not correct horizontal sync errors.

[lordsmurf]

He's referring to DVD recorders.

[jagabo]

He's referring to DVD recorders.

Sorry! I got here from the front page and didn't notice the section it was posted in.

I imagine a TBC in a DVD recorder would be a line TBC since they're cheaper.

[spiritgumm]

Can anyone tell me if this is vertical or horizontal signal problem with my vhs tapes? While playing the vhs, the video looks fine but if I put the vcr display on, it wiggles left-right.
When trying to dvd-record from these tapes, there are certain moments which will effect most of the dvd recorders I've tried - screen flashes slightly white like a loose cable.

[davideck]

Can anyone tell me if this is vertical or horizontal signal problem with my vhs tapes? While playing the vhs, the video looks fine but if I put the vcr display on, it wiggles left-right.

Yes, assuming that the OSD looks stable with an off-air source.
The OSD generator tries to synchronize to the source.

The OSD wiggling indicates that there is timebase error in the VHS source.
(It also demonstrates how well your TV is compensating for it.)

[spiritgumm]

I don't understand the explanation - the question was: is it a vertical OR horizonatal issue? It seems there is a separate solution to each, so I need to know which I need to correct for. Or does "yes" mean it's both vertical AND horizontal?
I don't know what OSD is either.

[davideck]

Sorry -

OSD = On Screen Display = vcr display

I was attempting to explain why the vcr display wiggled left-right; horizontal displacements of vertical edges...this suggests timebase error.

If the vcr display wiggled up and down then that would suggest vertical sync errors.

[spiritgumm]

Thanks! So I should seek a Line TBC, not a full frame TBC. I guess this is all obvious- special vcrs have Line TBC's to correct vcr-generated problems...just saw a post by 'Smurf that "line TBC's are worthless":
https://www.videohelp.com/forum/archive/t250528.html
The contradictory info about video equipment are like discussing politics. I think I'm going to cry.

[lordsmurf]

Don't take what I said out of context. The so-called "TBCs" found in DVD recorders do nothing and are worthless. The ones in S-VHS players are a godsend, and are true line TBCs.

[spiritgumm]

I didn't mean to take your comment out of context - sorry about that. If Line TBC's are the answer, are they available separately? I'm not going to look for old JVC vcr's.

[davideck]

How about an old Panasonic VCR...

https://forum.videohelp.com/viewtopic.php?t=287476

It sounds like your timebase errors are significant enough to benefit from a VCR with an internal TBC.

Are these first generation tapes, or are they copies of copies?

[spiritgumm]

My problem vhs tapes are from trades (copies of copies). Seems like most of the equipment discussed on that link are vcr's with internal Line TBC, except for the TBC1000 and Feral A4:2:2 which I thought were full frame TBC, not Line TBC. What I was wondering was are there are any stand-alone Line TBC? I'd rather not get another vcr.

[FulciLives]

My problem vhs tapes are from trades (copies of copies).

VHS can benefit from Line and Full Frame TBC's but BEWARE ... errors on multi-gen VHS tapes (applies to Beta and Hi8 etc.) cannot be fixed.

The TBC will be helpfull to an extent yes but the error is already "imbedded" into the signal if it is a copy of a copy so only SO much can be done.

- John "FulciLives" Coleman

[davideck]

I agree with FulciLives.

http://www.questronix.com.au/info/info_tbc.htm

There are standalone TBCs which do a fine job of timebase correction.
But it is hard to predict how any TBC will react to multi-gen embedded errors.

[spiritgumm]

Yes, the problem is on the vhs tape but it's not visible (except for when using Vcr onscreen display), and recording Vcr-to-Vcr is fine. Problems arise when I go Vcr-to Dvd. Dvd recorders are suppose to have the advanced equipment but they mess up. That's what's so vexing.
t

[lordsmurf]

They don't "mess up" but rather they expect a clean signal. Analog equipment did not care, and that's one reason multi-gen VHS was unwatchable crap 9 times out of 10.

[MeekloBraca]

TBC/Noise Reduction on some of these DVD players may not be much to you buffs, but its better than nothing and it is noticable on some tapes.

[spiritgumm]

I was reading Capmaster's TBC explanation- it sounds like a full frame TBC will "fix" both horizontal and vertical signals, not just vertical. Also sounds like a TBC can potentially make vhs signal problems worse, which is why the dvd recorders I've tried have messed up. The exceeption was the Panny es20 which wasn't effected by the major signal problems, but frequently gave me a loose-cable effect when there was no problems.