Bottom scan line sync problems from VHS & Hi-8 captures

[majyk]

Hello,

I've been browsing and searching and haven't quite seen any posts regarding my exact problem, so here goes...

To start at the end, I'm having a consistent problem during capture from both VHS and Hi-8 sources where the bottom few scan lines seem to go out of sync. I would appreaciate it if some of you could take a peak at a couple of samples that I've posted and hopefully give me some suggestions. There is one each of a Hi-8 capture (lovely ground shot from a zoo) and a VHS capture (auto racing). The full-size files are 8 and 6 MB respectively, so I've also created "sm" versions that are smaller in screen size and length, but still show the problem. Those are only 6xx KB each.

http://home.comcast.net/~h0wdyd0/sample1.mpg
http://home.comcast.net/~h0wdyd0/sample1sm.mpg
http://home.comcast.net/~h0wdyd0/sample2.mpg
http://home.comcast.net/~h0wdyd0/sample2sm.mpg

The capture card in question is one of the relatively new ATI TV Wonder Elite cards (PCI) based upon their highly touted Theater 550 chipsets. I will say that with my newbie taste and sensitivities, I am satisfied with the overall quality of these captures aside from this little problem.

My system is a recent HP xw4300 workstation with a P4 3.2 GHz single processor. I got this system to do CAD, so the video display card is an ATI FireGL V3100 card (PCI-e 16x) targeted for that function. With boxes of VHS tapes of old auto races and a dozen or so precious 8mm and Hi-8 Home video tapes, transferring them to DVD is a secondary use for this relatively high horsepower system.

I have downloaded the latest ATI drivers to no avail. I spoke to ATI technical support and they essentially blame the sources. While that is certainly possible, the fact that the problem is so consistent over a couple of different sources (VCR and Hi-8 Video Cam) as well as several tapes of various age, I am skeptical. Perhaps there is some incapatibility with this card in my system - the display card, perhaps, or some other driver or OS service running. I have yet to try swapping in a different display card, but I guess I may end up trying that.

Before I go out and get a different capture card to try (I'm thinking of the Hauppauge PVR-250), I'd like to get some opinions from some folks with some experience.

Thanks to all in advance.

Best regards,
Mike

[FulciLives]

It is normal.

That is there on all analog videotape sources be it VHS or S-VHS or Hi8 or Beta etc.

You do not see it on your TV because a TV has OVERSCAN meaning that the extreme edges (all 4 sides) are never seen 100% ... most TV's have a 5% - 10% overscan.

A computer monitor has no overscan so you see the extreme edges (all 4 sides).

Some people like to crop off the bottom then add black to it. For instance cut off 8 pixels from the bottom then replace with black. However, generally speaking, this can't be done at the capture stage but can be done when you encode to MPEG in software (assuming you capture to a high quality AVI type format first then use a software encoder to get to a MPEG-2 DVD spec file).

It ain't no big thing to leave it as be but personally I crop and add black ... in the old days ... now I have a stand alone DVD recorder which records the image as is so like I said no big deal either way.

You may relax now

- John "FulciLives" Coleman

P.S.
Just to confirm I did watch the first clip you posted.

[majyk]

Thank you for your reply (and sorry it took so long for mine, after your incredibly prompt response!).

Now that I finally broke down and asked this question, wouldn't you know that I ended up stumbling on the answer in another post. Now I know that what I'm seeing is a result of the heads switching from one to the other on the playback device. As you say - perfectly normal. I did a search on "head switching" and there are a bunch of posts on this...

Oh well, one good thing about my experiencing this problem - I was forced to find this excellent forum and the whole new world of Advanced Video Capture has been opened up to me.

I could well have been off on my merry way, simply capturing all of my old analog tapes direct to MPEG and with little editing onto DVDs. Heck, I would have whipped through my collection in no time!

Now, however, I know all about optimizing my playback with a good VCR, using a TBC to clean up problem tapes, capturing to AVI with VirtualDub, and processing the files with filters, etc. to clean things up before converting to MPEG. I now want to wait until I upgrade all of my hardware before I do this!

Wait - is that really a good thing? Perhaps ignorance truly would have been bliss...

Nah, I don't think so. I'm enough of a techno-geek and really only want to do this once, so I may as well do it well. I'll probably just get started with what I have and gradually improve the hardware as my knowledge improves.

Thanks again for the help and Best regards,
Mike

[thecoalman]

Wait - is that really a good thing? Perhaps ignorance truly would have been bliss...

:P Welcome to the abyss....

[lordsmurf]

Now, however, I know all about optimizing my playback with a good VCR, using a TBC to clean up problem tapes, capturing to AVI with VirtualDub, and processing the files with filters, etc. to clean things up before converting to MPEG. I now want to wait until I upgrade all of my hardware before I do this!

(I see the light bulbs flashing in your head)

Welcome to the club. 8)

This just proves the site works, and now you're on your way to making high quality DVDs, assuming you actually get the hardware and do the process.