Confused: Why a VCR with TBC if separate TBC needed anyway?

[lordsmurf]

"Timebase corrector" is sort of like say "a car" as far as I'm concerned. Cars can be built to go fast, to haul big loads, etc. Timebase correctors can also have variations in their specific task. Generally, this error is not going to be corrected by a standalone TBC.

If you know of a certain model that will, share it. But please don't go around and give people false hopes, especially when it concerns them spending $100's on the advice. That's something that really bothers me.

[davideck]

The FOR.A FA300 standalone TBC did a good job on these errors for me.
It wasn't perfect. It wasn't as good as the JVC internal TBC.
But it was better than the DataVideo 3000.

[davideck]

I surfed my way across this unit today;
http://www.primeimageinc.com/50II_SPEC.htm

Notice that it specifies a residual timebase error of +/- 15 nsec (Approximately one half pixel width). Higher quality standalone TBCs provide this specification.

(At 720x480, one pixel width is about 74ns.)

[mike1061]

This one looks expencive. They don't say how much it costs.
Thanks Mike

[BrainStorm69]

The DPS-290 has basically the same spec. for residual time base errors.

http://www.leitch.com/custserv/products.nsf/$All/D2EEEA8D5D67FDBC85256C95005FE08C?Open&Family=Synch ronizers%20TBCs%20and%20Proc%20Amps

[davideck]

As does this unit...
http://www.for-a.com/sub_html/p_product/fa125.html

[vhelp]

OK, had to recreate the vhs test tape, so its a little different. The vhs tape was recorded using my Mitsubishi HS-U781 to record from a test DVD I created.

Here are 3 caps:

(1) one from my JVC HR-S9900U, set to "edit," (remember the "sharp" setting doesn't work right on my 9900) with the TBC/DNR "on," R3 "off";

(2) one from my JVC HR-S7600U, set to "sharp," with the TBC/DNR "on," and R3 "off";

(3) one from my Toshiba M784 with DNR "on."


JVC HR-S9900U


JVC HR-S7600U


Toshiba M784

I did not use the Datavideo TBC-3000 for any of these. I might think about using the Toshiba for capturing if I had an external TBC that corrected the distortions in vertical lines like the JVCs' internal one does.

Davideck - I seem to remember that you have a TBC other than your TBC-3000. Does your other TBC correct the vertical distortions caused by time base errors that the TBC-3000 does not?

=============================================

@ BrainStorm69 ... great post on your latest test pics above

Regarding your posted response here [or above]:

Could please give the proper steps your acheived in producing these
images, from start to finish ??

Plus, the *image* (or test vob) that you used in those pics. I'd like
to run this same test on my JVC S-VHS HR-S3910U model, and test
its various recording modes using these images, for normal; edit; sharp;
etc. modes.

I'd like to run this over the weekend.

My goal is simple.. to investigate weather or not *my* vcr will produce
the same wavy verticle lines as in the last pic for the Toshiba demo
(above) I'm hoping that they are clean, but for the time being, I await
with anticipation

Thanks,
-vhelp 3764

[pijetro]

Brainstorm69 wrote:

I wouldn't use this comparison for purposes other than what it was intended for, which is to show that the TBC-3000 does not correct time base errors that cause distortions in vertical lines

I don't understand..Isn't that what it was intended to do?? I thought that the signal pulses that generate horizontally were buffered in the TBC memory, and spit back out, to correctly replace badly timed scans.

davideck wrote:

The datavideo tbc's are good frame synchronizers (in that they guarantee continuous synch to the capture device) but they don't do much in the way of actual timebase correction.

Now i'm realy confused..You mean to tell me that a frame can get synched (ie both fields belonging to the same frame), but somehow there's still a timebase incorrection?? How does this effect continuous synch??
Any links for a better understanding??

Thanx...

[davideck]

I hope this helps...
https://forum.videohelp.com/viewtopic.php?t=279530

[pijetro]

Thanx...

I'll print it out tonight, and put it under my pillow when i go to bed..
By morning time, i should fully understand it..

Great link BTW...

[BrainStorm69]

@ BrainStorm69 ... great post on your latest test pics above

Regarding your posted response

Could please give the proper steps your acheived in producing these
images, from start to finish ??

Plus, the *image* (or test vob) that you used in those pics. I'd like
to run this same test on my JVC S-VHS HR-S3910U model, and test
its various recording modes using these images, for normal; edit; sharp;
etc. modes.

I'd like to run this over the weekend.

My goal is simple.. to investigate weather or not *my* vcr will produce
the same wavy verticle lines as in the last pic for the Toshiba demo
(above) I'm hoping that they are clean, but for the time being, I await
with anticipation

Thanks,
-vhelp 3764

Test vob can be dl'd here:

http://s37.yousendit.com/d.aspx?id=32DOONQB733732KLVB6CQ7GZ5U

As for how it came into being:

I have searched over time for test images on the net and have various relatively high resolution jpeg test patterns. In this case, I only used part of the whole test image because it is 943x1479. So I cropped out a 720x480 portion and resaved as a bitmap.

Then I used Slideshow Movie Maker to create an AVI file of the image (and a couple of others, actually). I then used TMPGEnc to encode to MPEG at about 8000 or 9000 kbps cbr (I think). Then used TMPEG DVD Author to author the Test DVD.

Then used my Sony DVPNS575P to play it and my HS-U781 to record to a new, high quality VHS tape. Then captured the VHS from the three VCRs using my Avermedia DVDEZMaker using Virtual VCR and HuffyUV. Then used Virtualdub mod to screencap the same frame from each capture.

You can count frames pretty easily because there is a dissolve into that particular test pattern and you can tell exactly when the dissolve ends in each cap and count frames from there. I went 25 frames past the point where the dissolve finishes.

Let us know how things turn out, but make sure you tape the test pattern to VHS using another VCR other than the JVC you intend to test, otherwise you may not (probably will not) see any time base errors.

[mike1061]

I hope this helps...
https://forum.videohelp.com/viewtopic.php?t=279530

Is it possable to post a list of good ones, or how about the ones you think are best? I think that would save me and some other people from trolling around looking for things that we barly understand.
Thanks Mike

[davideck]

My experience has been -

The DataVideo TBCs (100/1000/3000) are valuable for eliminating A/V sync and Frame Dropping issues caused by Capture Devices (like my Hauppauge PVR-250) which get upset with tape dropouts and record gaps. They are also rather tolerant of multi-gen compounded timebase errors for tapes that are copies of copies. Nice units. However, they provide little if any improvement in image stability, and actually soften the image a bit. I compensate for this by using "edit" mode on the VCR.

The JVC TBC/DNR system does an amazing job of eliminating luminance jitters and chroma impurities, but it also softens the image and introduces (minor) DNR artifacts. It does not eliminate my A/V sync and Frame Dropping issues.

The FOR.A Commercial TBC that I have used falls somewhere in between, eliminating A/V sync and Frame Dropping issues while moderately improving image stability without sacrificing image detail. It is not as tolerant of multi-gen compounded timebase errors as the DataVideo TBC.

YMMV. A lot depends upon the source quality and the capture device characteristics. It is also possible for a TBC to make things worse on particular tapes.

For good quality S-VHS tapes, I have found that my older JVC HR-S6800 VCR (without TBC/DNR) and the FOR.A TBC preserves the most detail with minimal artifacts. My second choice is the 6800 and the DataVideo TBC. I use my JVC HR-S7600 (with TBC/DNR) and the DataVideo TBC for unstable tapes where the TBC/DNR benefits outweigh the disadvantages.

For more info -
https://forum.videohelp.com/viewtopic.php?p=1381787

Another good solution appears to be the Panasonic VCRs with internal TBC.
https://forum.videohelp.com/viewtopic.php?t=287476

[mike1061]

Thanks
Mike

[vhelp]

@ BrainStorm69

I knew I could count on you
I've D/L'ed the sample vob you posted earlier. I also liked your
in-depth response, "..how it came to be" too, thanks

(fwiw, today I spent the good part of the afternoon doing some research
on some items I made notes about during this past week. Anyways.
I found CC had a (IMHO) great sale on some no-name brand "nexXtell" DVD-R
disks.. $6.99 for 25pk, and $9.99 for 50pk. I got the 50pk.. everywhere,
even Staples had a 25pk for $19 bucks, hehe)

So, I'll use one of these as a test disk for your vob sample to burn
it on. And, I will report back, my results, soon as I can.

-vhelp 3766

[vhelp]

@ BrainStorm69.., Sorry for the OT update here..

Well, unfortunately my attempt at making a test DVD from your "Vts_01_1.vob"
(on a newly purchased CC no-name brand 50pk -R disks) but the file failed to
play in my Apex AD-1500 player. Nero had complained that the file dumped into
it was not dvd compatible.

(I had installed Nero v5.5.10.45 bundle version that came with my
Optorite burner, while connected to internet here, but I turned down option
to reboot for now, so that I could burn a quick test -R disk)

I will try other measures to get a -R disk properly burned, and perform
the tests that I am eagerly wanto to do.

(fwiw, today I spent the good part of the afternoon doing some research
on some items I made notes about during this past week. Anyways.
I found CC had a (IMHO) great sale on some no-name brand "nexXtell" DVD-R
disks.. $6.99 for 25pk, and $9.99 for 50pk. I got the 50pk.. everywhere,
even Staples had a 25pk for $19 bucks, hehe)

-vhelp 3768

[BrainStorm69]

@vhelp - different approach. Here is a new DL of the whole TS_VIDEO directory of the test. You should be able unzip into a VIDEO_TS folder and burn to DVD without authoring, etc.

http://s37.yousendit.com/d.aspx?id=3EQ4AG90C66LF1UXUV2FM6AA7I

[vhelp]

Thanks again BrainStorm69 for your assistance with your new vob file.

(But, I will D/L it later on, when I finish up with some other things
I have on my agenda. I do want to test it out on my AD-1500 player
to be sure that it was not *your* vob file that was at fault, but was
rather something I have to do regularly during these situations.. no-biggy)

I will follow-up with my success shortly, as I found out what I was doing
that cause my earlier AD-1500 player's failure.

-vhelp 3769

[vhelp]

Ok. I met up with success. This time, I took a different approach as
BrainStorm69's new vob file would indicate that I did in my own attempt..

Here's the receipe, case others want to try their hand on it w/ *their*
VCR / DVD player setup:

** using TMPGenc, open MPEG Tools
** de-mux the vob file into *.m2v and *.mp2 files
** now, open the beloved ifoEdit tool and re-author to new
... vob; ifo; bup; files, and point to a blank video_ts folder and save there.
** using your DVD burner of choice (mine was Nero) author to .50 cent DVD-R.

That's it. Now run your own tests using your given setup.. good luck

Next, I'll post my results now..

-vhelp 3770

[BrainStorm69]

@vhelp - definitely looking forward to your results.

[vhelp]

OK, here are my results.. as originally planned for this weekend

I had to re-do them because I found out (at the tale end of my smiling face)
that I had an S-VHS tape in the vcr during the recording tests. And that
had wared me out, and so I took a break and rested up for a while.

It is my guess or belief that..

Several things can "sway" the results to some degree or another. For instance,
comparing one capture card to another. Or, comparing one DVD player to another,
or VCR's, or vhs taps, etc, etc. So, there is no perfect set of test results,
only as perfect as your given setup will allow, is your next to best/perfect
test result.

I did notice that on Regular tapes, there is aparent noise. I guess this is
normal for these tapes. After souly using S-VHS tapes in my many recording
projects and for so long, I had forgoten how noisy Regular tapes can be.

And after working with S-VHS type recordings for so long, I can safely say
that my guess is that this format is next closest thing comparitable to Analog
Cable tv quality. Not a bad comprimise.

And last, regarding the tape quality playback of the recording.. please
note that this VCR brand does not have any DNR (noise reduction) circuitry
what-so-ever. So, as you are viewing these pics, please bare that in mind.

(by now, you know I gotta have a remark or too, to fit into a closing)

.
.

OK. So I made THREE recordings for this test scenario.

The last, S-VHS test, made its way into this test by accident, and was actually
the first test run I made before I had discovered it was not a regular vhs tape
for this test. Anyways, here are results, from Worse to Good:

** test.pattern.ad1500.rca_vcr.svid.advc.ep.1.png ---- reg. vhs tape, EP
** test.pattern.ad1500.rca_vcr.svid.advc.reg.1.png --- reg. vhs tape, SP
** test.pattern.ad1500.rca_vcr.svid.advc.svhs.1.png -- S-VHS tape, SP

In block diagram form:

AD-1500[out: RCA] -> VCR[in: RCA, r-VHS, EP][out: S-Vid] -> ADVC-100[in: S-Vid]
AD-1500[out: RCA] -> VCR[in: RCA, r-VHS, SP][out: S-Vid] -> ADVC-100[in: S-Vid]
AD-1500[out: RCA] -> VCR[in: RCA, S-VHS, SP][out: S-Vid] -> ADVC-100[in: S-Vid]
AD-1500[out: RCA] -> sony.vcr[out: RCA] -T- JVC.vcr[r-VHS, SP][out: S-Vid] -> ADVC-100[in: S-Vid]
AD-1500[out: RCA] -> sony.vcr[in: RCA, r-VHS, SP][out: RCA] -> ADVC-100[in: RCA]

And here was how I manufacture them:

** setup is for both, Regular and S-VHS tapes.
.
** Equip: Apex AD-1500 dvd player - Output: RCA wire
** Equip: DVD-R test disk
** Equip: JVC S-VHS HR-S3910U - Input[RCA] / Output[S-Video] wire
** Equip: regular vhs tape, (and S-VHS tape)
** Equip Setting: "Edit mode"
** Equip: ADVC-100 (DV) capture device - Input[S-Video and/or RCA] wire (pend test)
.
** I set the AD-1500 player in repeat mode while I recorded several takes to tape
.
** When I was finished recording to tape, I proceeded to capture to DV, the tape.
** I used my ADVC-100 (dv device) to capture the whole (5 minute) recording.
** Then, I ran the DV AVI file [type 2] inside vdub and from the timeline, I
** picked out the best pic(s) and saved to .BMP file: vdub->file->save_image_seq

Note, RCA = Composite (just dif. words)




** test.pattern.ad1500.rca_vcr.svid.advc.ep.1.png ---- reg. vhs tape, EP




** test.pattern.ad1500.rca_vcr.svid.advc.reg.1.png --- reg. vhs tape, SP




** test.pattern.ad1500.rca_vcr.svid.advc.svhs.1.png -- S-VHS tape, SP




** test.pattern.ad1500.rca_vcr.svid.advc.svhs.1.png -- reg. vhs tape, SP, Sony SLV-685HF to JVC HR-S3910U
(note, the sony vcr is old, and dirty most likely aiding to recorded results )




** test.pattern.ad1500.sony.rca_sony.rca.advc.sp.1.pn g -- added Tue, Jan 24, 2006
-- AD-1500 -to- sony.vcr[r-VHS, SP], (sony[r-VHS, SP] -to- advc -- all RCA wire --


I'm sure that the above test receipe could be improved or the steps modified.
Otherwise, I think I got everything down, that I needed to get down -- I hope
And for those just comming in to this thread now, please read from page one.

From the Video Workstation of,
-vhelp 3774

[davideck]

vhelp - GREAT pics!

What was the Playback VCR? Nice stable playback.
Was the SVHS tape capture a VHS recording?

Man, the noise difference between SVHS and VHS tape is amazing.
What brand of tapes did you use?

[vhelp]

vhelp - GREAT pics! -- Thanks.

What was the Playback VCR? Nice stable playback.
Was the SVHS tape capture a VHS recording?

I'm not sure what you mean here. I recorded BrainStorms69's test vob file
(I had problems initially with it, till I found a work-around by using ifoEdit
to recompile [author] to a new DVD set of files, then burned to DVD-R disk with Nero)

Then, I played the test vob inside my Apex AD-1500 dvd player, via RCA wire to my vcr.
Then, I made serveral types of recordings to S-VHS and Reg. vhs tapes, in EP and SP, and
Then, I hooked up the vcr's output lead, output: S-Video to my ADVC-100 input: S-Video
and captured the tape while it played.

But I want to point out that what causes most of VHS transfer problems is
the devils servant, Macrovision. Because these F up your anything and
everything (you know what they all are) you have issues with either of
frame drops, or distorsions of several kinds.

But, because I my *source* video was not Macrovision'ised, there were no
issues to contend with for any of my devices. That is a key element to
consider when *capturing* sources from VHS.

One of the first things that cought my eye were the stableness of
the Virtical Lines. I thought for sure, that I would get very
bad and wavy line, and was expecting the worse. I was wrong

You know, when I first initiated the test, (as I noted earlier) and
reviewed the captured AVI source, I couldn't believe how great it
had looked, and I was pretty stunned. I was so overwhelmed, that I
wanted to post my results right away, but then I pulled out the tape,
(what ? ..its an S-VHS tape -- oh no) and that was the end of my world,
and I shrivalled up into a tiny raisin.

So, after I got my barings together, I restard with an old tape I made
of the Sydney 2000 Olympics, (packed away in a storage box full of VHS
tapes for one day to transfer to DVD how ironic) and use that
tape for the regular vhs tape test, EP and SP mode recordings.

Man, the noise difference between SVHS and VHS tape is amazing.
What brand of tapes did you use?

As for the S-VHS tape brand, I wish I knew. But I don't know. but
what I do know is this.. I've made so many recordings on-top of other
recordings on that tape, and I use it regularly, and I also know that
it is *serveral* years old. But, if there is a way to tell, by looking
at the tape areas and/or numbers printed.., I'm all ears as to what brand
it is

I was gonna do an S-VHS EP mode recording, but I got frustrated on
account of my wanting to close out this planned weeked promise of
completing these tests. Well, I ran into some trouble, and it took
longer and some extra work. But I guess the results paid off.

-vhelp 3775

[davideck]

I realized after I posted that you had listed the vcr...sorry.

It sounds like your SVHS tape capture is an SVHS recording, while your VHS captures are VHS recordings?
So the noise difference may also be due to SVHS vs VHS recording?

[vhelp]

It sounds like your SVHS tape capture is an SVHS recording,..

YES. During the time I was playing the AD-1500 dvd player vob file,
I was recording it to my vcr, with two grade levels of tapes..

First recording (while AD-1500 player is still playing, in repeat mode)
was with an S-VHS tape, and the vcr automatically configures itself
with SVHS attributes.

Second recording (while AD-1500 player is still playing, in repeat mode)
was with a regular VHS tape, and the vcr automatically configures itself
with the regular VHS attributes for this grade level.

..while your VHS captures are VHS recordings?

YES again, as indicated in above's explanation.

So the noise difference may also be due to SVHS vs VHS recording?

Precisely

I don't use regular vhs tapes anymores. Other than what I have still,
and/or in storage, waiting for the final transfer to DVD or other,
I sometimes might use a regular tape for tests and things, like this
one.

When you record to a regular vhs tape, and the source is video, I would
not worry so much on the noise level. But rather consentrate on the
archival transfer and MPEG methods. I know I've said this before, but..
for most transfer type projects, the better method of MPEG encoding
is best done with CBR and highest bitrate your given dvd player(s) will
allow or play without hickup. I regularly use CBR and 9000 bitrate in
all my Capture and Encode to DVD type projects. These are mainly from
my DV captures. And, the reason why I chose DV as the codec of video
is on account of my dv device PROS. No drop frames, perfect audio sync,
and pure clean video.

( Man, I can't wait till I finally get back my old Analog Cable hookup.
Suppose to be this later part of this week. I choose Analog for its
purest nature. Non-digital, meaning no MPEG / MPEG artifacts such as
blocks, DCT blocks, pixelsations, etc, etc.

And, recording to S-VHS tapes will prove better than the digital ones
because of what I mentioend above, about the mpeg artifacts and all.
Better to put up with slight Analog Cable noise then the MPEG ones. )

Sorry, I guess I ran farther than I was suppose to in this topic.

-vhelp 3776

[BrainStorm69]

One of the first things that cought my eye were the stableness of the Virtical Lines. I thought for sure, that I would get very
bad and wavy line, and was expecting the worse. I was wrong

@vhelp - I haven't got the time right this minute to review your post in detail (halftime of Mavs game and getting kids in bed), but I think the reason for the stablity (i.e., no wavy lines) is because you used the same vcr to record as you did to playback for capture. One of the main points of my original test was to specifically use different record and playback vcrs. I think you are much more likely to see time base erros in that situation than if you record and playback on the same vcr.

Be back later to review more carefully. BTW, thanks for all the effort!

[vhelp]

@ BrainStorm69

I had (good and lazy) reasons why I did not use another VCR. Mainly
on account of not wanting to dig it out of the closet. But, the other
vcr is an old Sony one. The brand, if it matters, is: Sony SLV-685HF

But, if you insist..

-vhelp 3777

[vhelp]

Ok. I modified my previous post of all the test pic samples and have
now included another one, but this time, according to BrainStorm69's
request.

I used my Sony SLV-685HF vcr for this last test's closeout and
analysis. Thus, I hooked up my AD-1500 dvd player to the Sony vcr, and
RCA wire, and recorded to the Sony in SP mode w/ regular vhs tape.

Then, I took the tape out of the Sony, and shuved it into the JVC vcr and
pressed record, and SP mode.

Then, finally, captured the JVC vcr to my ADVC-100 (dv device) and used
same method with vdub, noted above in previous post to obtain .BMP pic,
finalized to .PNG file as other pics.

(note, because its been so long since I used this vcr regularly and feature'wise,
I can't recall proper "optimum" setings, and as such, I just popped in a tape
and started recording)

Please see the above, [page 2] for more info and latest pic.

Enjoy, thank you, and have a good night sleep.

From the Video Workstation of,
-vhelp 3778

[BrainStorm69]

Ok. I modified my previous post of all the test pic samples and have
now included another one, but this time, according to BrainStorm69's
request.

I used my Sony SLV-685HF vcr for this last test's closeout and
analysis. Thus, I hooked up my AD-1500 dvd player to the Sony vcr, and
RCA wire, and recorded to the Sony in SP mode w/ regular vhs tape.

Then, I took the tape out of the Sony, and shuved it into the JVC vcr and
pressed record, and SP mode.

Then, finally, captured the JVC vcr to my ADVC-100 (dv device) and used
same method with vdub, noted above in previous post to obtain .BMP pic,
finalized to .PNG file as other pics.

(note, because its been so long since I used this vcr regularly and feature'wise,
I can't recall proper "optimum" setings, and as such, I just popped in a tape
and started recording)

Please see the above, [page 2] for more info and latest pic.

Enjoy, thank you, and have a good night sleep.

From the Video Workstation of,
-vhelp 3778

Well, it appears as though what I thought would be the case is - taped on one vcr and played back on another = time base errors. It looks a little noiser also. As far as optimal settings for capturing with the Sony, I don't think there is much to set on those old Sonys (I have a couple) as long as you had auto tracking on. I think most of the other things you may have available on the Sony, such as Automatic Picture Control (APC) and "edit" mode, only affect playback, and not recording.

One question realted to the recording with the JVC on VHS tape. Does your JVC support SVHS-ET recording? If so, are you sure that the VHS recording on the JVC wasn't done in SVHS-ET mode? My experience with SVHS-ET is that it does give a bit better resolution, but more noise than regular VHS recording. Those VHS tapes just were really not made to handle the bandwidth, I think.

I think that most VCRs exhibit some time base errors on pre-recorded VHS tapes also. In comparing captures of various pre-recorded VHS tapes played on my JVCs with the TBC on vs. caps from other VCRs without TBCs, I have frequently noticed subtle time base errors in the caps from VCRs without TBCs. They are not easy to see without comparing exact frame screen caps unless there are vertical straight lines in a particular scene, but they are there. I'm interested in that as well as tapes made on different vcrs because I also have a significant number of pre-recorded VHS tapes to back-up.

One thing that is significant, as Davideck pointed out - the S-VHS cap was WAY better and less noisy than the VHS caps. I got a great deal on some S-VHS tapes the other day at Fry's. They are TDK S-VHS Pro tapes that originally sold for 7.99 apiece that I got for 90 cents apiece. I bought every one they had (11 in total). I'll certainly be using those (rather than VHS tapes, no matter how good) for any more video taping I do in the future.

Also, I'm hopeful we can get some other folks to use this test with VCRs without built-in TBCs, but with commercial grade external TBCs to see if the commercial grade TBCs can remove or lessen the waviness caused by time base errors that the Datavideo TBCs don't.

Finally, vhelp, thanks again for your efforts on this!! I think threads like this help us all to better understand our hobby.

[davideck]

the S-VHS cap was WAY better and less noisy than the VHS caps.

This may be dependent upon the VCR.
I notice that your Toshiba VHS VCR pics of VHS playback are clean.
I also notice that your JVC SVHS VCR pics of VHS playback are noisier, similar to vhelp's VHS pics.

Perhaps the JVC SVHS VCRs do not perform as well with VHS tapes as the Toshiba VHS VCR?