Larger then normal black bar when using TBC

[gammer]

I normaly get a black horizontal bar on the left side of my screen when I capture from VHS. It is small enough that it gets covered up by the overscan on the tv.
However, if I run my VHS source through my VT2500 TBC, sometimes this black bar is so big that the overscan does not cover it up.

Is this normal?

I have been using the clip and mask feature in TMPGEnc for the time being to fix it. But I wonder if there is a way to adjust this within my TBC?? I'm worried that I am losing picture on the right side of my screen if somehow the TBC is pulling the picture to the right.

I can provide screenshots if it would be more helpful?

Thanks,
gammer

[edDV]

I normaly get a black horizontal bar on the left side of my screen when I capture from VHS. It is small enough that it gets covered up by the overscan on the tv.
However, if I run my VHS source through my VT2500 TBC, sometimes this black bar is so big that the overscan does not cover it up.

Is this normal?

What you are seeing is horizontal delay. Defined as video delay relative to the horizontal sync pulse.
I haven't seen this. What capture card are you using?

Is there an active input to the VHS deck? Where is it coming from? Try disconnecting this input and see if there is a change.

[gammer]

What capture card are you using?

ATI AIW 7500.
But as you will see with the screen shots below, this problem seems to occour when the TBC is in the chain. I don't think its the video card.

My set up: VHS player to Leitch VT2500 TBC to ATI AIW 7500 capture card.

Is there an active input to the VHS deck?

There is nothing being inputed into the VHS deck.
Also I have tried differnt VHS players with all the same result. This big black bar appears when I use the TBC.

Here are some screenshots of what is going on and an explanation before each screenshot (please note: these were all taken from the same VHS movie from the same VHS Deck. The only variable is the TBC and the position where the movie is at):

This is with the TBC at a point in the movie where the black bar is covered up by the overscan.



This is with the TBC at a point where the black bar is not covered by overscan.



This is without the TBC at a point in the movie where there is almost no black bar.



This is without the TBC, but the black line is back, but covered by the overscan, almost like the first image that has the TBC



Should also note that this happens with other movies, not just with the one in this example.

[edDV]

The black bar is caused by horizontal sync being first stripped from the video and then replaced by the TBC.

High end TBC's have the following modes to deal with the issue:

Internal / External Sync
This selects whether reinserted sync comes from the original video (delayed) or from an external source or from the TBC itself.

Horizontal Phase
Adjusts video horizontal video position relative to the sync pulse.

The block diagram and adjustments on high end TBCs are well documented and understood. Consumer TBCs remain a mysterious black box.

This is without the TBC, but the black line is back, but covered by the overscan, almost like the first image that has the TBC
...
Should also note that this happens with other movies, not just with the one in this example.

This may be a clue. You say this happens without the TBC in the loop. Is this from the VCR just hooked up to the AIW? Are there any inputs to the VCR? Try unhooking them.

[gammer]

This may be a clue. You say this happens without the TBC in the loop. Is this from the VCR just hooked up to the AIW?

Yes. It seems like at certain points during this movie the black bar is thicker then other times. Even when the TBC is not hooked up...just VCR strait to the AIW.

I'm not sure if you are familiar with the movie I am capturing - Mystery Scienc Theater 3000? Anyway, when its during the part where they are not watching the cheesy movie, the black bar is normal. But when they are watching the cheesy movie, the black bar is thicker. Again, this apparent with or with out the TBC in the loop. However, as you can see from the pics, the TBC makes the black bar worse as you explained by stripping the horizontal sync and replacing it.

Are there any inputs to the VCR?

There are no other inputs hooked up to the VCR.

So from what you are saying there might be a way to adjust this?

[gammer]

One more thing...
If you look at the second picture, you can see that there is almost no empty seat in the pic in the lower right corner, but in the fourth pic you can almost see half of the empty seat in the lower right corner.

This is what makes me concerned about losing some of the picture on the right side.

[edDV]

One more thing...
If you look at the second picture, you can see that there is almost no empty seat in the pic in the lower right corner, but in the fourth pic you can almost see half of the empty seat in the lower right corner.

This is what makes me concerned about losing some of the picture on the right side.

Since the MST3000 creatures are watching an old movie, the aspect ratio difference could be causing the black side bars (narrow ones) in the original video.

Your first and second picture clearly show a right position shift.

[gammer]

edDV

I fixed the problem.
I started to explore the circutry on the TBC board and found a very small adjustment marked "HPOS".
I grabbed a very small screwdriver and adjusted it. As I turned it, it moved the Horizontal position and I lined it up as best as I could.

Now I have to go back and re-capture all of the ones that were done before I fixed it

Thanks for your help,

gammer