What is Time Base Corrector (TBC) and do you need it?

[@martontichi8611]

thank you very informative video. i love you channel just came across it and there is so much useful and professional info here.

[@maxheadrom3088]

Thank you, sir! Excellent video!!!!

[@Lfe-l8n]

Some of old vhs c recorded by a mitsubishi camcorder in the 90s have picture roll during the first second of a sequence... i d k why this problem appears on the tape ... i use a jvc with tbc inbuild for the play-back but the picture roll still persist a little 😢

[@ConsumerDV]

My VHS camcorders also stabilize the picture horizontally, but show an occasional picture roll on bad tapes. I run these through a Digital 8 camcorder, which has a stronger TBC. I've yet to acquire a DVD recorder to use a TBC.

[@Lfe-l8n]

@@ConsumerDV thanks, i think is better if maybe a choose a good external Tbc. I think the tbc inbuild in the jvc camcorders are good to preserve the frame but gives some littles picture roll ... not the best when we want to save our precious memories

[@KNOFGHD1]

Which specific 80's VCR are you refering to ? I've never seen a "standard vhs deck" with a "built in tbc" here in europe. Super-vhs i sure did.

[@ConsumerDV]

I said "hi-end VCRs", not "standard VHS deck". I went through dozens if not hundreds video magazines published in the 1970s, 1980s and early 1990s. You can see everyone was feeling that digital video was right around the corner since mid-1980s. Many VHS machines were marked with huge "DIGITAL" labels only to mean either digital pause mode or digital effects or digital picture-in-picture. Some of them had a TBC, and I got an impression that 1987-1990 were the years when TBC was about to become a standard feature for top-level VCRs. The June 1990 issue of "Video" magazine published the article "Top decks adopt a picture-fixing feature". I suspect that movie companies had their hand in stifling the adoption of TBC, they did not want consumers to make better copies, just like they were fighting double-cassette video decks and they were recording off-the-air television earlier. I am surprised they had agreed to CDs, but back in the early 1980s a PC HDD capacity was only 5 to 80 MB, so the labels felt safe. Anyway, I cannot provide specific model numbers for Europe, all I can suggest is to go through magazines, sorry.

[@ivok9846]

​@@ConsumerDV yeah, "digital" in 80s and 90s is what "ai" is today, advertising gimmick that...well..doesn't really work...esp. in this field. i recently saw ebay listing fro toshiba 'v3' technology, but i dunno if they called it tbc. i think i have some review in "video magazine" from 90s for that deck. so it may be that "digital picture improvements" were separate to "proper" tbc, which indeed was only on s-vhs decks, i think. ie i don't think you can find tbc on non-svhs deck. there is toshiba m781 ad in video magazine feb/march '96 and review of m-761 in dec '95. ad talks about DNR, and article is called "heads first" (19micron heads for slp...frankly that days nothing about standard speed which uses different set of heads). article carries sentence "slp playback looked equally fine with and without them" while talking about 19micron heads. which is nonsense, as slow speeds use 2 different heads. that's why sp/lp models have at least 4 heads. ad says m781 is first vcr with DNR. shows noise lines in before/after image. ie dnr removes loise lines. neither vcr is advertised as having tbc, tbc is never mentioned. in europe there were not much of, for example, toshibas, hitachis or mitsubishi vcrs. i guess they sold stuff where market was bigger. i would say even jvc was less sold in europe, where panasonic and sony were probably best sellers. and some german brands, but that was probably all made in japan (for example fisher..that was probably sanyo underneath). some philips, some grundig. dunno how much of those were dutch/german products. ie who made mechanisms they used etc. toshiba m781 boasts 6 video heads, so that would be one pair for each of speeds, sp, lp and slp(also called ep). that issue of v. magazine has a short description of mitsubishi hs-u760 deck. s-vhs. tbc not mentioned, in either article or on front panel of vcr. so probably not even all s-vhs decks had tbc.

[@KNOFGHD1]

@@ivok9846 Nope that's toshiba Pro Drum version 3, totally different than a TBC. it's a way to assemble the drum and preamp together so there is less noise on the picture due to interferences. Pro Drum is great i have tested two vcr's with it

[@ivok9846]

@@KNOFGHD1 yeah, 2nd paragraph of my reply says tbc is never mentioned in context of Toshiba v3. I was recently wondering (when one of my VCRs malfunctioned) could it be that preamp was inside head drum. but it wasn't. how was power supply to that v3 preamp done, via one more coil on rotary transformer, but feeding power to drum instead of carrying video signal to main PCB? that would mean it has 6 (video heads) + 2(hifi) + coil to supply head preamp. geez.... that's a lot. overall I dunno if v3 can beat Sony hifi models from late 90s, but I doubt it. it's already too sharp video image.

[@KNOFGHD1]

@@ivok9846 what you can do is foil-shield the ribbon cable ( to reduce E.M.I) that goes from the drum's pcb to the preamp, you might gain something (less noise). SP use 2 heads, LP use 2 different heads that's 4 heads. 2 more Heads for Hi-Fi sound (one for left/right channels) that's 6. On "pro decks" there is another head (flying erase head) for precise editing. Can be 7 heads. not couting the Audio/control and Erase heads otherwise that's 9 total

[@ivok9846]

i need to dload this clip and inspect doc hollywood... i miss miss anna.

[@NBAONDVD]

I have many TBCs

[@ivok9846]

ok, there indeed is some horizontal jitter that tbc cured, but what's your resizer that makes his shirt so jaggy even after tbc? what compression was used on capture? could you provide short source sample?

[@ConsumerDV]

The tape is not the best quality, indeed. The DV version has only one audio channel, my fault. Also, I could adjust procamp on the VC500. On the other hand, the Digital8 camcorder is brighter than all my other capture tools. TBC ON: VHS -> SVideo -> Digital8 camcorder with TBC ON -> DV (107 GB): mega.nz/file/16VEBAzL#j1gxBO6ZBC5xmvaapgyHN6rjGQcgasNdmzDl1mbRmAY No TBC: VHS -> SVideo -> Diamond VC500 -> VDub into Cineform (96 GB): mega.nz/file/d6M2FY4C#inzwjfYGmbRNBf-Fa3KR4uTL6k9IiwU-IUaXKzhoJGQ

[@ivok9846]

​@@ConsumerDV thanks, i can't even post links on yt, any sort of links...last time i checked....luckilly sizes are in MB, not GB. in the beginning of the video, tbc version, when he enters, my god those blinds look bad!!! i mean i'm usually talking how bad pre-recorded tapes are in regard to image sharpness, but this is not that, this is just whole another level of bad resizing! who released this tape? maybe it's just ntsc lores, but...damn.... something i wanted to rise before, but my replies were not being published so i skipped it: ivtc is not perfect and can sometimes pass combed frames, that's why her hair was combed, not h. jitter. vdub's IVTC filter is not decombing non-tbc footage at all. selecting top or bottom field first, doesn't help. what format does diamond output anyway, mpeg2? usb device? i'm converting some vhs, i'll show you preserved v.sync even with ff (fast forward) and extra noise on the tape. that's on top of stuff i already posted (ep on sp speed and pure white noise...hehe). but yeah, i do get h.jitter, it's easy to see on subtitles, but not easy to see on all other elements of the picture.

[@ConsumerDV]

The Diamond outputs uncompressed 4:2:2 8-bit. I prefer using Cineform for capturing, but maybe I should switch to lossless. IVTC filter is not perfect, but most of the time it works.

[@ivok9846]

​@@ConsumerDV diamond is the card i didn't have nice words for in prev. video (comments) too, right? slanted image? load that video to vdub2 and inspect frame counter on the bottom: it's dropping frames like mad! if u use "deinterlace" filter in vdub, and do "unfold fields" and "double framerate tff" you'll see there's no ntsc 2:3 pull down pattern there, 2 fields should be repeated, then 3, then 2 again etc.....(inspect wiki article on telecine, 2:3 chapter). no wonder ivtc is not working. my god that device is flawed, i hope it wasn't expensive. btw. how can it be uncompressed when it's usb2.0 device? usb is not even close to datarates of uncompressed 422, i don't even know if usb3 would cut it.... i think it captures to mpeg2 first(for proper interlacing support). dunno what software u use to end up with anything else. 2kliksphilip used something simillar (magix usb device) for his vhs project. also interesting experience with s-vhs machine(incredible difference between his old vcr and "new" s-vhs with tbc), although i doubt his diagnostic/repair is ok, you don't lose chroma because of vcr mechanics. once you watch that video, my comments will be clear. video iis called "VHS Tapes to Digital - preserving my childhood".

[@radpopl]

@@ConsumerDV Digital8 may seem brighter because it outputs a signal in the range of 16-255 rather than 16-235.

[@ivok9846]

still can't post links, not even yt....and i can't reply to thread i started..... posted few more clips on yt channel for this account. sd, hd and point-resize(nearest neighbour) could be slightly better (for yt) if the mpeg2 step was removed (mjpeg straight to mp4), but i won't be changing my destination format (laced mpeg2) because yt is crap anyway, and new codecs (divx, xvid, 264, 265) don't like noise too much. but vhs on yt can look better than 95% of people are doing it. i mean, i've found just two yt channels that are properly transferring analog video....one on frank zappa, and another that did some hi8 and vhs with vapoursynth qtgmc...oh yeah, another is "video dump". i can do qtgmc on the fly (for playback of laced mpeg2) on newer pc anyway. AND sony lcd tvs have good denterlacers and scalers. that's why i don't care about tbc, not much h or v. sync issues there (even with damaged tape capture is not stopping) and it would introduce some blurring. and i hate any blurring. if i was in this for the money, and many tapes would have much timing issues, then yes. this way, no.

[@lordsmurf]

You're really mixing up a lot of terms and concepts in this video, and that may lead to a person buying the wrong TBC (or non-TBC item) for their digital conversion needs. Yes, TBCs are needed. And yes, the correct TBC will improve quality. But not necessarily for the reasons stated in this video. For starters, ancient broadcast TBCs really have no overlap, nothing to do with modern TBCs made for consumer analog videotape formats. "TBC" is a wide term, with many loose definitions, and it has changed over the decades.