Vertical line "jitter"

jkraus wrote on 1/3/2005, 10:52 PM
I would appreciate some help.

I have had this problem before. After rendering video looks fine on PC, but after making DVD the vertical lines (especially when the scene is panning) is jumping all over the place, make you sick to watch.

Before, I thought I fixed this by using a better encoder (using Render to VFW Avi then encoding with CCE) but having the problem again. I suspect it is something to do with Interlace, but I know just barely enough on this subject. Am I on the right track? I see the "switch" in Vegas about interlace, but I have tried too many different tacts to know if this was even helping.

Thanks in advance

Joe

Comments

farss wrote on 1/3/2005, 11:02 PM
Have you done anything at all to the footage? FXs, pan/crop etc?
What camera was it shot with?
Is EVERYTHING set to lower field first apart from the mpeg encoder?
What bitrate are you encoding the mpeg-2 at?
Bob.
Grazie wrote on 1/3/2005, 11:50 PM
Apologies to just to confirm this, but, you do mean Vertical? You don't mean horizontal? . .. G
jkraus wrote on 1/4/2005, 7:46 AM
OK, here are the stats:

Shot with Sony TRV33
Rendered as :Video for Windows" avi
Encoded with CCE at 8Mbps
I don't know what is meant by "everything set to lower field first..."
Yes, I mean vertical

But, again, it looks fine in preview mode of DVDA, just after making a DVD an viewing on the TV, so I thought interlaced related.

Any more thoughts?

Joe
jkraus wrote on 1/4/2005, 8:27 AM
It appears to me that I may need a more precise description, as interlace may not even be the issue.

When I watch the resultant dvd on TV it looks fine until the scene action is a pan. Then any verticla lines (like the edge of a building) "jitter" back and forth (vibrate left and right) as the pan happens, making you almost dizzy.

This vertical line "jitter" stops whenthe pan stops.

Any help is appreciated.

Joe
Barry_Green wrote on 1/4/2005, 10:40 AM
It does sound like you have a field-order problem, like your field-order got reversed.

If so, it would indeed look fine on a computer display, which displays both fields at the same time. But on television, the fields are displayed one after the other, at equal increments in time, and were imaged one after the other... if you get the field order "backward", it would play field 2, then field 1, then field 4, then field 3... resulting in the behavior you've described.

When motion stops, the field order is much less relevant (i.e., on a still shot).

So I'd say it's most likely a field interlace issue. When you go to make your MPEG-2, check whether you have "upper field first" or "lower field first" selected. Whichever you have, reverse it and try again, it should fix your problem.
jkraus wrote on 1/4/2005, 1:11 PM
Thanks You!

I was not aware of "field order" but since I have read the Vegas 5 manual at work and now understand. It indeed sounds like it could be the problem. The only thing I changed in the default template for "Vidoe for Windows" avi was the video quailty setting was from "good" to "best".

Could this be the problem? Or perhaps using CCE as my encoder (does it also have a settingfor field order?). Or is this just the random luch of the draw?

In any case, thanks for your help and I will try tonight when I get home.
Barry_Green wrote on 1/4/2005, 1:55 PM
Don't know anything about CCE, but I would suspect that it does have its own setting for field order.

You can verify where the error is coming in by playing back your rendered .AVI through the camera onto a television. If it still looks good, then the problem is not caused at that stage, and would be due to your CCE settings. If the rendered .AVI has the same motion problem, then obviously it was introduced based on the settings you used to render out your footage.
jkraus wrote on 1/4/2005, 9:56 PM
Barry, you are the man!

Indeed it was a field order problem. One interesting twist though. I capture from a Sony TRV33 inot Vegas. It says the media is "lower field first". I render to VFW avi as Lower Field First. I then Render in CCE, but the only way I get to jitter to stop is select Higer Field first in CCE (counter intuitive), the lower filed first selection induced the jitter.

Go Figure?

Anyway, its working, so thanks!

Joe
farss wrote on 1/4/2005, 10:20 PM
From memory the standard for all DVD mpeg-2 is UFF, I agree very confusing. Just stick to the supplied templates and all will be well.
Bob.