stacking TBC - what effect does this have on a transfer?

[P_Townshend]

Hey,
I have a JVC SVHS deck equipped with TBC/DNR and also have an AVT-8710 (which works flawlessly, by the way) and am wondering that, if using the AVT unit in conjunction with the JVC SVHS TBC/DNR function what am I to expect?

has anyone had any experience with this? Will there be any artificially induced artifacts because of this?

Thanks in advance,
Darreni

[gshelley61]

The more devices a video signal is run through, the more degraded the signal will become. Artifacts and video noise compound with each additional step of processing. However, the cleaned and stabilized video output from the "DigiPure" DNR/TBC processor in your VCR probably won't be noticeably degraded with only one additional pass through the AVT-8710, and can actually be enhanced further with the adjustments on the device.

[qlizard]

Test it and let us know.

[Dr_Layne]

I run a JVC SVHS HR-S9800U with TBC on thru a Datavideo TBC-1000 Every once in a while I will run into a tape that will cuase frame drops on my datavideo DAC-100 even with the JVC's TBC on. So I keep them both on. It's a pain when you are an hour and a half into a two hour capture and you drop frames.

Steve

[fmctm1sw]

Test it and let us know.

I too have a SVHS VCR with a built in TBC (Toshiba) and am considering getting a TBC-1000 or AVT-8710. I would also be very interested in the results of testing (before I shell out $300)....

[lordsmurf]

I've been using a JVC 9800 TBC passed into a DataVideo TBC-1000 for at least a year now.

No adverse affects, in fact, I get better video because of it. The signal is about as purified as it can get.

I'm about to add another device or two in the line-up, but I've been paying attention to different things (such as my S/N posts and PMs to various people). Even adding another device or two, I should be fine.

[DVWannaB]

I've been using a JVC 9800 TBC passed into a DataVideo TBC-1000 for at least a year now.

No adverse affects, in fact, I get better video because of it. The signal is about as purified as it can get.

I'm about to add another device or two in the line-up, but I've been paying attention to different things (such as my S/N posts and PMs to various people). Even adding another device or two, I should be fine.

lordsmurf,

I have the same set-up as you do. What other pieces of equipment are you looking to add? Maybe it is something I should be looking at also. Thanks.

[lordsmurf]

I'm in the process of getting some detailers and proc amps.
gshelley in this forum has been doing the same things recently.

I've sought out these product:
Sign Video (aka Studio 1, aka Vidicraft)
Vidicraft
Elite Video
Archer

I've gone after detailers and proc amps. They're often called enhancers, stabilizers, etc. These are not the crap anti-MV devices though, these are for enhancing detail, and correcting color and video values. They have NO USE for MV or stuff like that. This is to improve the video signal.

New, some of these are generally $300-600 each. Used, you can find bargains as low as $10 on eBay, though some are still about $200 or more. Quite a few are about $50 or more each.

Specifically, I went for the Elite BVP-4 Plus, the Vidicraft Detailer II or III, and the Sign Video DR-1000.

I should have all these soon, and will test them out for a while.

This will all be in a chain, with existing TBC-1000, JVC 9800 DNR/TNC, possibly JVC DRM10 DNR, and then 1-2 of the new items. Likely the detailers always for VHS, the proc amps when needed.

Oh, and I think I need a new desk. This stuff doesn't fit anymore. In fact, I need a bigger office. The floor is becoming my desk. Good storage closet would be helpful too.

[pluche]

I also use a Datavideo TBC 1000 but in de chain I add my old Kramer SV-4E super VHS corrector which allows me to adapt color, video gain and definition; its a kind of semo-pro machine which I still kept from the days of analogue video camera;
for average tapes, an increase in video gain and a slight decrease in definition does the job and finally gives me a better quality than the original tape; color correction depends on the tape; the machine has a splitter so I can immediately judge the settings

[fmctm1sw]

This is all very interesting to me. I like seeing what other folks use for playback hardware... Currently I have 3 VCRs and a 6 way switch. I'm looking in to a TBC. I also found a A -> D converter that advertises a TBC built in and picture controls as well. Depending on cost (the only one they had was a version without the TBC), I may look into that...

[DVWannaB]

Oh, and I think I need a new desk. This stuff doesn't fit anymore. In fact, I need a bigger office. The floor is becoming my desk. Good storage closet would be helpful too.

If you are getting a larger office and new desk, I will too. I am getting everything lordsmurf gets.

[DaveS]

Currently I have 3 VCRs and a 6 way switch.

what switch are you using? A switch would make things easier but I was afraid of the extra noise from a cheapo circuit city $24 switch..there are others our there but they cost...plugging and unplugging cables gets to be a hassle but to me it keeps the signal a little better..not sure if it really makes a noticable difference though

[lordsmurf]

I refuse to use a switch. I see MASSIVE quality problems unless it's an expensive pro switch. For that much money, I'll get off my lazy butt and move wires around.

[gshelley61]

Every connector, wire, adapter, switcher, processor, A/D converter or other device the signal goes through, the more chance there is for signal degradation and interference noise. The more direct the connection, the better. And use good to excellent quality shielded cables! No $3 cheapies...

[DaveS]

I refuse to use a switch. I see MASSIVE quality problems unless it's an expensive pro switch. For that much money, I'll get off my lazy butt and move wires around.

that's my feeling .. I looked into some switches but they were a few hundred $, min. haven't seen any on ebay but haven't looked...the cables are expensive enough, so I'll just keep using those - it keeps the runs shorter too

[fmctm1sw]

Currently I have 3 VCRs and a 6 way switch.

what switch are you using? A switch would make things easier but I was afraid of the extra noise from a cheapo circuit city $24 switch..there are others our there but they cost...plugging and unplugging cables gets to be a hassle but to me it keeps the signal a little better..not sure if it really makes a noticable difference though

It's a Japanese market Ascii brand with S-Video inputs for each of the 6 inputs. It didn't notice much difference. Maybe I'll do some testing and see exactly how much noise is generated. I just could dig behind my vcrs and computer anymore with all the testing I was doing. Maybe I'll ditch it when I get a permanent setup...

[fmctm1sw]

Sorry, in a hurry....

Switch:



No switch:



No switch and DNR in "soft" position on VCR:

[gshelley61]

Does that switch has some kind of DNR? Is it a powered signal distributor/amp? The second frame (straight from the VCR) has the most detail, with a bit more noise. I prefer clarity over a soft picture, but some like the "smoothed" low-noise look.

[fmctm1sw]

Does that switch has some kind of DNR? Is it a powered signal distributor/amp? The second frame (straight from the VCR) has the most detail, with a bit more noise. I prefer clarity over a soft picture, but some like the "smoothed" low-noise look.

I was going to describe it exactly the same way. I was going to say the switch resembled my Toshiba VCR when I use the DNR in "soft." It's just a dumb box, not powered. I know you don't have the benefit of the original bitmaps, but with the switch in the path, the picture is actually "bent" or "warped" slightly. I also prefer sharpness over a softer look. My original plan was to use the switch to test my VCRs to find the right setup. But, each of them has it's own strengths and weaknesses. So I left the switch there and never thought about it.

[lordsmurf]

I think that switch is just limiting resolution, no DNR.

I personally like clean video, be it soft or sharpness. Just clean.
The big reason I got the detailer was to re-extract detail after images are softened to remove noise. The detailed images will hopefully be as sharp as the original, but without the noise.

[fmctm1sw]

The big reason I got the detailer was to re-extract detail after images are softened to remove noise. The detailed images will hopefully be as sharp as the original, but without the noise.

That is my biggest problem with my captures. I've tried all kind of filtering schemes and everything I tried removed detail to some degree. I just didn't like it. That's why I pretty much just capture and encode straight up. I'd love to get rid of that noise and keep detail...

[gshelley61]

The Vidicraft Detailer is great because the variable detail and sharpening adjustments really work and are quite powerful. Depending on the source, a small or relatively large amount of enhancement can be used before too much video noise and grain become an issue. The variable enhancement noise reduction adjustments on the Vidicraft (VNX and Black) can also be applied to tone down some of the introduced noise, though in some cases it might be better to not use these and simply turn down the Detail and Sharpness.

The JVC DVD recorder does a good job of suppressing some noise during the encoding process, so when I use the Vidicraft Detailer I try to push the enhancement to the point where I have as much detail as possible, without excessive noise and edge ghosting - then let the JVC take care of some of that. It is a fine line, though. For each new source, a bit of trial and error and short recording tests using various settings is advisable. And don't over-do the enhancement... use all of the adustments (Detail, Sharpness, VNX, Black) sparingly if you like a smoother, less noisy picture. Push them up higher if you like a more detailed image with a sort of grainy, film-like appearance. Too much enhancement results in annoying motion artifacts and excessive video noise.

The display type has an effect, too. Direct view CRT's are very forgiving and conceal quite a bit of noise (that's why broadcast signals can look pretty good on them). Fixed pixel, high resolution displays (LCD, DLP, etc.) are not good at masking noise and therefore all flaws in the video signal are revealed. Their advantage is when they are fed a clean, high res image they look fantastic.

[Steen4]

Reading through this thread has inspired me to post the results of some informal compression testing I did after I received my Datavideo TBC-1000. The object was to determine what effect, if any, stacking tbc's would have on signal compressibility.

source: jvc hr-s9911u
external device(s): datavideo tbc-1000
capture device: philips saa7108-based capture card (ok, ok, gainward geforce3 64mb powerpack!!! golden sample w/vivo)
computer: screw it...see the computer details button at the top of the byline
capture program: virtualvcr resolution 352 x 480/half d1
capture codec: picvideo mjpeg, quality 19, luminanace changed to 2, chrominance changed to 3

I am using the mjpeg codec for a couple of reasons: first, it's what I use for my longer captures; second, it achieves a higher level of compression, thereby making the effects of reconfiguring the devices a little easier to quantify. By the same token, though, I didn't want to use anything lower than 19 with mjpeg. Posting the outrageous compression ratios achieved with lower settings would have smacked of hyperbole. Anyway, on to the numbers.

hrs9911u: mode edit/soft, tbc on/off
tbc-1000: active/physically bypassed

Testing involved capturing a short clip with moderate amounts of movement (from the sci-fi channel) in S-vhs mode, sp speed, using s-vhs tape (so many details...) and capturing through the s-video connection to virtualvcr, where the compression ratios are displayed.


1. vcr: edit/tbc off, tbc-1000: active - compression: 3.349
2. vcr: edit/tbc on, tbc-1000: active - compression: 3.274
3. vcr: edit/tbc on, tbc-1000: bypassed - compression: 3.240
4. vcr: soft/tbc off, tbc-1000: active - compression: 4.216
5. vcr: soft/tbc on, tbc-1000: active - compression: 4.508
6. vcr: soft/tbc on, tbc-1000: bypassed - compression: 4.606

I would have bet my life (ouch!) that using both tbc's in tandem would have given more stable, hence more compressible results. This arrangement, however, provided only middling results in comparison to just using one or the other, depending on the vcr's playback mode. What happened?
Finally, before I release my observations into the wild to be perused (and savaged) at large, a couple of things: first, the jvc's tbc shifts the picture slightly to the left and condenses/narrows the image a little. Does anyone else see this? Second, I didn't do any testing in the vcr's auto mode. Do you think I should have? Would it have changed the gist of the information? Lastly, some might wonder why I didn't perform 'raw' captures for comparison to the processed ones. It's really nothing to bother about. TBC's are an indispensable element of obtaining a quality capture (all you have to do is see it once to believe it), so posting information about the raw captures would really have been a waste of everybody's time, and at some point, you have to start applying Occam's razor to it, in a manner of speaking.