any kind of field viewer

[Rafael Amador]

Hi Dennis,
FC can’t do it, but if you set your canvas at 100% in any scene with a bit of movement you will be able to know if the field order is properly set just stepping frame by frame..
You can do it in AE and Shake. I don’t know if Motion offers the option.
rafael

http://www.nagavideo.com

(and here some clips for the friends: https://www.vimeo.com/2694745 )

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[Dennis Couzin]

Rafael, I’m not sure that method can be trusted. The FCP viewer shows two fields interleaved into a frame. How do we know which of these fields will be shown first when the video is displayed interlaced? For example, suppose the camera took fields in this temporal order: …I,J,K,L,M,N,… and suppose the viewer shows a frame consisting of I&J, then a frame of K&L, then a frame of M&N, etc. These frames will look OK, with minimal zigzag. But if somehow the field order had become screwed up in the file, like …J,I,L,K,N,M… then the viewer could have shown those same decent frames, while an interlaced display of fields in the order …J,I,L,K,N,M… will have terrible jitter. I think that this can happen with some codec conversions if they are not properly applied (or not properly written). I managed to make the jitters once, and want to be sure I don’t again.

In fact, if anyone’s interested, I’ve posted 5 conversions of a 16 frame interlaced clip at https://www.mediafire.com/download.php?dnytvummgld. I don’t know if any of them have screwed up field order, but I did calculate that the fall-none.mov file contains exactly 16½ frames worth of data. The other three uncompressed files contain exactly 16 frames worth. How did that extra ½ frame (= 1 field?) get into that file — thank you, FCP — and what does it imply for the field sequence in fall-none.mov?

[Andy Mees]

Can’t be done in FCP Dennis … rubbish eh? Go to Apple’s FCP feedback page and explain what it is you are wanting to do and why it would be useful for you:
https://www.apple.com/feedback/finalcutpro.html

… let them know that you are downloading and installing the AVID Media Composer 14 day free trial in order to get the job done:
https://www.avid.com/forms/info.asp?iTrackingID=MC35TRIALDL

[Dennis Couzin]

Thanks Andy for both suggestions.
Voilà, Avid Media Composer 3.5 is in my Thinkpad now.

Problem 1: The 8-bit QTs import fine, but the 10-bit uncompressed QTs import as all white. I can step through the frames, so the clips are there, but I just see white. I installed Avid Codecs PE to no avail.

Problem 2: I can only step through frames. How does one step through fields in this application?

[Dennis Couzin]

This strand has shifted to the Avid Editing forum https://forums.creativecow.net/readpost/45/871644
where surprising results are presented.

[Andy Mees]

LOL. I had imagined you would be installing the AVID trial on your Mac so the first condition wouldn’t have occurred … as for the apparent field order issue that you are seeing, its probably/possibly just a incorrect interpretation during the AVID import.

[Dennis Couzin]

I’ll keep the discussion going on here and also at https://forums.creativecow.net/readpost/45/871653.

If Avid QuickTime import can’t be trusted to keep field order straight, then how can Avid be a method for checking the field order in a QuickTime file?

I did the basic experiment. Some video came out of a Sony DCR-VX2000E. It was definitely shot as DV-PAL. I captured it with FCP using the DV-PAL preset. (There is no option for field dominance in the capture settings.) I put it in the timeline and set sequence settings to DV-PAL with lower field dominance. I rerendered and exported a QuickTime using current settings. Then I set sequence settings to DV-PAL with upper field dominance. (This is the wrong setting for DV-PAL.) I rerendered and exported a QuickTime using current settings.

I imported both QuickTime files to Avid and stepped through their fields. Both showed the field reversal: 1 step backward; 2 steps forward; 1 step backward; 2 steps forward; etc.

It appears that either FCP exports DV-PAL QuickTimes incorrectly or else Avid imports DV-PAL QuickTimes incorrectly. DV-PAL is not an obscure codec. The error seems too large to be possible (unless FCP or Avid is known making for big errors).

[Dennis Couzin]

Andy Mees, I don’t get your LOL that I installed the Avid trial on my PC. Would you dare install it on a Mac having FCP installed? The Avid software was pretty agressive on install. Windows XP screamed and begged not to continue the install. But I can flush my PC easily after the trial. Is there no danger that installing Avid will disturb an existing happy FCP installation on a Mac?

Oh, my finding the fields out of order was a false alarm. I needed to set the field dominance in Avid before letting it import the QuickTimes. It surprises me that a QuickTime file of interlaced video isn’t organized into fields. Is it organized into frames? Does it not even specify which lines of the frame are temporally first? How can a QuickTime player do a good job of deinterlacing without that information?

[David Roth weiss]

[Dennis Couzin] “I don’t get your LOL that I installed the Avid trial on my PC. Would you dare install it on a Mac having FCP installed? The Avid software was pretty agressive on install. Windows XP screamed and begged not to continue the install. But I can flush my PC easily after the trial. Is there no danger that installing Avid will disturb an existing happy FCP installation on a Mac? “

Dennis,

For the record, when it comes to installing and uninstalling apps without doing damage, Apple is vastly superior to Windows. The Windows registry is notorious for clinging onto remnants of everything ever installed, which is something the Apple OS for the most manages to avoid.

I’m no Apple fanboy, just a long-time Windows user who really appreciates this major difference between the the two operating systems.

David Roth Weiss
Director/Editor
David Weiss Productions, Inc.
Los Angeles

POST-PRODUCTION WITHOUT THE USUAL INSANITY ™

A forum host of Creative COW’s Apple Final Cut Pro, Business & Marketing, and Indie Film & Documentary forums.

[Dennis Couzin]

David, I feared that Avid would install its own codecs which would confuse FCP, so I did it the cautious way: making a bootable partition with both FCP and Avid on it. I put them together since Avid needed FCP’s codecs to read the 10-bit uncompressed 4:2:2 QuickTimes exported by FCP.

Anyhow, field stepping in Avid found none of my sample QT clips to have their fields out of time order. It was all a false alarm.

I think there are two completely different ways to have screwed up fields. The first kind shows up as wild jittering when there is motion, especially when viewed on a CRT, but looks perfect when there is no motion. In this kind, the order of the fields comprising each frame is reversed, so, as the fields are stepped, action goes 1 step backwards, 2 steps forward, 1 step backwards, 2 steps forward, etc.
The second kind is subtler and shows up as exaggerated interlacing, the same with or without motion. In this kind, what should be the even lines are odd lines and what should be odd lines are even lines. In each frame, instead of presenting lines 1,2,3,4, etc. in correct geometrical order, it presents lines 2,1,4,3, etc.

The first kind of screw up definitely happens. Since a small error in coding could produce the second kind, I suspect it happens too.
The first kind of screw up is best examined by watching a moving subject field by field. Avid lets you do this while FCP doesn’t. It doesn’t matter whether the motion is horizontal, vertical, or at an angle, since it’s a temporal problem.
The second kind of screw up is best examined by looking at any one frame from a clip where some part of the image is perfectly still. Set the view to exactly 100% and study the pixels along a sloping edge in the image using a loupe.

The first kind of screw up is wrong “field dominance”. I don’t know if the second kind has a name.

Chris Pirazzi, who obviously understands this stuff, does not make the distinction clear in his “All About Video Fields”.