What's the right way to fix a field order problem?

[brassplyer]

I'm finding that video processed by Pinnacle 9 is consistently having issues with field order problems. I.e. when combining segments from good video, the end result has a field order problem. I.e. you see this blurry ghosting particularly noticeable when there's horizontal motion and when you check it with the Bob Doubler in Virtualdub, you see the "two step" effect - the subjects go up and back instead of consistently one direction.

I'm using Virtualdub as my fixit app, apparently simply using a field swap filter isn't the right way to remedy this. What's the recommended method of fixing this?

Thanks

[jagabo]

Field swap in VirtualDub does not fix field order issues. It is a fix for a very particular problem where the scan lines are stored in the wrong location.

You should be able to override the source field order in Pinnacle Studio. I haven't used Studio in a long time but as I recall, after adding the video to the timeline right click on it and select Properties. Change the field order there.

If you can't override the field order in Studio you can reverse it in VirtualDub by shifting the entire frame up (or down) by one scan line. Use the Crop function to remove one scanline from the top. Use the Resize filters letterbox option to add one scanline to the bottom.

[brassplyer]

You should be able to override the source field order in Pinnacle Studio. I haven't used Studio in a long time but as I recall, after adding the video to the timeline right click on it and select Properties. Change the field order there.

No such animal in PS9.

If you can't override the field order in Studio you can reverse it in VirtualDub by shifting the entire frame up (or down) by one scan line. Use the Crop function to remove one scanline from the top. Use the Resize filters letterbox option to add one scanline to the bottom.

I'll go through this to verify I'm doing what you're referring to.

Use the Crop function to remove one scanline from the top

The only way I see to invoke cropping is when there's a filter loaded so since you mention the resize filter, I'll load it.

This is what you're talking about?


However, when you say Use the Resize filters letterbox option to add one scanline to the bottom

It's not clear to me where in the filter you specify adding it to the bottom. And what should I be adjusting, the size options or the framing options?

[jagabo]

What you have there looks exactly right. If you look closely at the input and output panes you should see that one line has been removed from the top, one black line added to the bottom.

By the way, the Letterbox option doesn't let you specify how much gets added to the top vs the bottom. I just happen to know that adding one line will result in the line being added to the bottom.

One warning: if your source is YV12 VirtualDub will screw up the color channels. Use AviSynth to open the file and ConvertToYUY2(interlaced=true) or ConvertToRGB(interlaced=true) before giving the video to VirtualDub. If your editor will accept AVS script you can do the filtering in AviSynth instead:

WhateverSource("filename.ext")
ConvertToYUY2(interlaced=true)
Crop(0,1,-0,-0) #remove one scanline from the top
AddBorders(0,1,0,0) #add one scanline to the bottom

You can also change the field order by recombining fields:

WhateverSource("filename.ext")
SeparateFields() #separate frames into fields
Trim(1,0) #throw out the first field
Weave() #weave the remaining fields back together into frames

[brassplyer]

Doing some experimenting, I seem to get about the same result using the "field delay" filter, using Top Field First. Is there a reason why one method would be better than the other?

[lordsmurf]

If this is an MPEG file, just do this: http://www.digitalfaq.com/guides/video/edit-mpeg-field-order.htm

[brassplyer]

I'm working with DV AVI source files captured off a Digital8 camcorder. As an update, I find when actually watching examples of these "fixed" files using both the "crop one from the top and add one to the bottom" method and the Field delay method, rendered to a DVD on a TV, while they look different than the problem file - i.e. the file processed through PS9, there's still artifact problems with horizontal motion onscreen - in this case people walking in front of the camera. If it weren't for the horizontal movement, you probably wouldn't notice anything.

[jagabo]

DV should be bottom field first. Pinnacle Studio should be able to identify that correctly. Are you sure there's not something else odd about your files? Are you resizing the frame at all? Post a few small samples, before and after.

[brassplyer]

DV should be bottom field first. Pinnacle Studio should be able to identify that correctly. Are you sure there's not something else odd about your files? Are you resizing the frame at all? Post a few small samples, before and after.

Not resizing other than for the one fix attempt as advised above to crop one field from the top and add one to the bottom, which doesn't actually result in a resize.

Here's a sample from an original source file as captured from the Digital8 camcorder, used direct stream copy to make it. About 4.8 secs/16 megs. Checking with Bob doubler no back and forth.

http://www.fileden.com/files/2008/3/11/1809238/original.avi

Here's the same sample run through PS9. Checking with Bob doubler you get the back and forth motion.

http://www.fileden.com/files/2008/3/11/1809238/through_pinnacle.avi

Now using the crop fix method as described above

http://www.fileden.com/files/2008/3/11/1809238/crop_fix.avi

Now using the field delay filter

http://www.fileden.com/files/2008/3/11/1809238/field_delay_fix.avi


The issues and artifacting may not be as obvious on a computer screen, when rendered to a DVD and played on a tv they're very obvious.

VOB rendered version of the original file

http://www.fileden.com/files/2008/3/11/1809238/original.VOB


VOB rendered version of the same sample through PS9

http://www.fileden.com/files/2008/3/11/1809238/thru_ps9.VOB

[jagabo]

Good job putting those samples together. Here's what I see:

original.avi: this is a normal, bottom field first, DV AVI file

through_pinnacle.avi: this is a DV AVI file but there is something very messed up with it. The two fields are no longer separate. They have been blended to together in some odd way.

crop_fix.avi: DV AVI again but something went wrong with your field reversal process. The two fields are no longer separate, they're blended together in some odd way.

field_delay_fix.avi: similar to crop_fix.avi but maybe not quite as bad. Something's gone wrong. By the way, I didn't know about this VirtualDub filter! It must be a fairly recent addition. I do most of my filtering in AviSynth now so I hadn't noticed it.

original.vob: this is a normal, bottom field first, interlaced MPEG 2 file. It should play properly when burned to a DVD (DVD MPEG 2 can be either TFF or BFF). Although, if you're mixing TFF and BFF material the editing/authoring software may get confused. How did you make this?

thru_ps9.vob: once again there is something seriously wrong with this video. The two fields are no longer separate and blended in some odd way.

Given that something went wrong with both your field reversed AVI files something must be going wrong within VirtualDub or the encoder. Did you start with original.avi? Did you do any other filtering? What DV decoder did you use? What DV encoder? Did you force a colorspace on the input or output (Video -> Color Depth in VirtualDub, or maybe in your DV codec)?

Another problem with exporting as DV AVI: after reversing the field order the frames are TFF. But there is no way (as far as I know) for a DV encoder to flag its video as TFF. Most editors will assume it's BFF. You need to find some way of convincing Pinnacle that it's TFF. Unless, of course, Pinnacle is already assuming TFF for some reason.

[brassplyer]

Given that something went wrong with both your field reversed AVI files something must be going wrong within VirtualDub or the encoder.

The problem I believe is in Pinnacle Studio's re-rendering to DV-AVI. The problems seem to be when taking the original files, editing them together as one DV file - or just re-rendering to DV as you saw with the "through_pinnacle.avi". The original file that looks okay was captured through Pinnacle - and I guess it's technically really just a transfer, with the camera dumping the bitstream to the hard drive, using PS -via my Soundblaster Audigy's Firewire port. PS9 doesn't seem to mangle it at that point.

Did you start with original.avi?

In the examples above, I started with a piece of one of the original source files as dumped to the h/d directly from the cam. "original.avi" which as you see looks okay is simply a piece of that file direct stream copied via Virtualdub.

Did you do any other filtering? What DV decoder did you use? What DV encoder?

No other filtiering, using Mainconcept DV codec 2.4.16

Did you force a colorspace on the input or output (Video -> Color Depth in VirtualDub, or maybe in your DV codec)?

Here's the MainConcept configuration window as it's currently set.

[jagabo]

Looking very closely at through_pinnacle.avi it looks like the frame has been resized vertically by a small amount. That is probably the source of your problems. The question becomes where does that happen?

Why can't you use original.vob? Where did that come from?

[brassplyer]

Looking very closely at through_pinnacle.avi it looks like the frame has been resized vertically by a small amount. That is probably the source of your problems. The question becomes where does that happen?

Why can't you use original.vob? Where did that come from?

I made the .vob files to show that the problem or lack thereof came through with conversion to .vob - i.e. DVD - as well. If the original looks okay, the vob looks ok and vice-versa.

I made a DVD out of the project and it looks fine on a TV. The problem seems to be when Pinnacle creates a DV avi file. I did a preliminary test of a short segment checking "change fields order" on the Mainconcept configuration window and that seemed to get rid of the problem, at least on initial inspection. Generally the only reason I would create an AVI would be to then create an mp4 or other file to put up online or to use that AVI as part of a larger Pinnacle project.

And actually, now that I think of it, I may have also had problems when applying filters in Vdub. If checking the field order box makes the difference, maybe I just have to remember to do that.

[brassplyer]

[s:f75b9d74fa]So far it appears this field order setting on the codec configuration window is the key. I just made a DVD out of a test file that had been run through Pinnacle but this time with the change field order box checked - the file checks out with the Bob Doubler test, and the DVD looks fine on the tv.[/s:f75b9d74fa]


Nevermind, I see there are severe problems with a file created that way.