VHS Tape Crooked top of picture

[Chunking]

Ok,
I have a VHS tape that I want to convert to DVD. Not a problem I can record it on a DVD recorder than load it into the PC. The problem is the picture on the tape when viewed is crooked at the top. I wasn’t sure what to call that so I wasn’t sure what to search for. So sorry in advance if this has been posted. However, here is the thing. I captured this tape before on some old equipment. I had an old cheap capture card. When I converted this tape on the capture card it straightened the picture up. Great, but that capture card was unable to record at a high resolution. It was only able to capture at a small MPEG 1 resolution. The card doesn’t have any out jacks where I could use it as a pass thru. I want to capture this at a DVD resolution. Is there any software or filters that can straighten the picture out? If the old capture card can straighten the picture out I’m sure there must be some software or filters that can straighten out the picture.

[mats.hogberg]

When you play the resulting DVD back, I'm sure the warping will be outside of the visible area - IIRC, some capture cards crop the image to avoid garbage "always" present at the top/bottom of analog video. Maybe that's why you didn't notice it in your computer captures?

/Mats

[mikel]

If you are still willing to search the subject....google " tape skew "

It happens because of bad tensioning on older decks.

[Chunking]

Hmmm, the tape was warped pretty good. I didn't notice that much being cropped out. It was at least almost 1/4 of the top part of the screen. I would have noticed that much picture being gone. I think the card managed to straighten it out somehow.
thanks for the info

[SingSing]

Watch that tape with that VCR on TV, first.

[dphirschler]

My bet is the skewing is only present in one field. Your cheaper capture card probably only captured one field.

Not that it will sove your problem, but go back and take a look at that old capture card. A lot of times you can get high-res captures out of it using different software or drivers. Unless of course it is an external USB Dazzle or something like that.


Darryl

[Chunking]

It's an internal card. I don't know the brand of card off hand. I bought it off a friend. Whenever I tried to get a capture larger than 320x240 it would have distortion and be choppy. I'll take another look at the card.

[mats.hogberg]

Try capturing to a low (or no) compression AVI that you then reencode to the desired format.

/Mats

[BrainStorm69]

Sounds like "flagging" to me. Try searching for that - there are plenty of posts about it. Best resolved with a TBC (time base corrector - a piece of hardware).

[thecoalman]

Watch that tape with that VCR on TV, first.

I'd do that first, or if you already know that let us know... if looks good on the VCR to TV connection and you capture results look like this or something along thte lines of this:




Then you've probably been bitten by a false MV signal. Won't be present on your old card because it won't have MV detection. Does it have a flicker to it too?

[Chunking]

It's similar to that. It's bent at the top. It looks like that on the tv using many different VCRS. However, when i ran it thru my cheap capture card on the pc it straightened it out making it look good. however that card could not capture at a high resoulution. Now I capture stuff using a DVD recorder and just load that disc into VS9 and edit the video. It is a home video so there is no macrovision.

[thecoalman]

It's similar to that. It's bent at the top. It looks like that on the tv using many different VCRS. .

The above does not apply then. TBC will probably fix it but that will cost some dough and is not guranteed.

[gjb0219]

As Brainstorm69 and thecoalman say, it looks like you need a TBC - a good one - which hopefully would fix the problem.

FYI (and I got this tip from LordSmurf on another Forum posting) the input circuits of the Panasonic ES10 DVD recorder have a truly "magical" ability to fix such skewing problems. I used to have skewing problems with many of my older homemade (ie non-Macrovision) videotapes, even when using my JVC 9800 S-VHS VCR which incorporates some TBC circuits. But since acquring an ES10 on ebay and using it simply as a pass-through to my HDD DVD recorder for recording I have yet to find a videotape that I can't "un-skew."

[Chunking]

thanks everyone,
I was trying to figure a way to use pass thru on the card but it has no outs. I only have one tape (the girlies at the beach). So I'm gonna have to do some experimenting. I'll report my findings for future reference if I get it straightened out.

[BrainStorm69]

It would be interesting if you can find out what card it is. As mentioned, with different software or better drivers, it may be able to capture at higher resolutions. If it did straighten out the problem with the tape, it would be interesting do do some tests with it.

[Chunking]

I did a quick check. It's a conexant (not sure it's spelled right) PCI card. I'm at work now I'll get the model # when I get home. I did a quick look and I ran the tape thru the card and it straightend the picture out. I also did a quick test by recording the same tape onto a DVD and then loading into VS9. The picture remained crooked. Somehow the card manages to straighten the picture out.

[handyguy]

Looks like you might have stored your VHS cassettes laying down, thus crinkling them. Store on end if possible

[mikel]

Just another note on "skew" problems.
15 years ago, skew problems on industrial (3/4") VCRs were adjusted mechanically.
There was a small felt pad that would drag (place tension) on the supply hub.
By mechanically adjusting (with a knob) the pressure of that pad, skew problems could be
delt with. I even made a similar setup in on a couple of my 1/2" VHS decks,
making the skew adjustable from the back panel.

A lot of vhs decks that I have seen have a 3-position spring tensioner for this.
But I would not advise playing with this, unless you are comfy with
the innerds of a vcr.

[FulciLives]

I did a quick check. It's a conexant (not sure it's spelled right) PCI card. I'm at work now I'll get the model # when I get home. I did a quick look and I ran the tape thru the card and it straightend the picture out. I also did a quick test by recording the same tape onto a DVD and then loading into VS9. The picture remained crooked. Somehow the card manages to straighten the picture out.

It if is a conexant and it is old than chances are it is a BT chipset.

If that is the case (BT chipset) then you can use the btwincap WDM Video Capture Driver which can be found at the following website:

http://btwincap.sourceforge.net/

Using that driver you would want to capture at 712x480 for a NTSC source. When it comes time to encode it to DVD you can add 4 pixels to either side to make it 720x480 or you can crop it to 704x480 and encode it that way although it probably is better to encode at 720x480. If you decide you want to use 352x480 I would still capture at 712x480 then crop it to 704x480 then resize to 352x480 ... this all assumes you capture to an AVI file using a codec like HuffyUV or PICVideo MJPEG etc.

If you capture at 720x480 then your aspect ratio will be off but then again since it is only off by 8 pixels I doubt you will be able to see it as the human eye is not that sensitive to an aspect ratio error of that (very small) amount.

You don't want to capture 352x480 on a BT chipset card as it will create a very soft image. Better to capture at 712x480 then resize in software later on.

- John "FulciLives" Coleman

[zoobie]

Thought it was called it a tear or tearing...

[Chunking]

I've had it for three years so I'm thinking it's about 4 years old. If I can capture at 712x480 that would be fine as I don't think there will be much loss when I re-encode to Mpeg2. I'll try the new drivers out and see if I can capture it at a larger size.