Lower or Upper field first

[JohnDale]

Hi
Iam using VS10. I recently had a problem with jittery video after burning a DVD. Found the solution to the problem (wrong field selected) by reading through the forum. But i am still a little confused. From what i understand it doesn't matter wether upper or lower field is selected when transfering from a Digital camera via firewire as long as the same field is selected throughout the project (from camera to DVD). Is this correct?
I also transfer my old home movies from VHS to the computer VIA the Digital camera (firewire) again from what i understand upper or lower field doesnt matter (as above). I always transfer to the computer as DV (AVI) wether from the digital tape or VHS.

Thanks for your help.

[sjj1805]

The FIELD order is determined by the method of transfer into your computer.

If the source is DIGITAL
Camcorder to hard drive via firewire
You require LOWER field first.

If the source is ANALOGUE
Mainly from a TV Card
You require UPPER field first.

If the source is a still image
Mainly from a digital camera or scanner
You require FRAME based.

Like every golden rule there are exceptions but these are in the minority.

[blplhp]

Hi Steve,

Your answer regarding the field type for digital photos confused me a bit.

I assume that if your VS project is comprised mainly of DV footage (DV_AVI from a digital camcorder) and mixed with a few still images (I always use photos in my projects with .bmp format), your editing Project Properties and your rendered video file Properties should still be set to Lower Field First, correct?

I assume that even a project that is comprised of a photo slideshow (from digital photos) only for playback primarily on a TV set, you would still render the project using Lower Field First, correct?

I thought that Frame Based field type was primarily used for playback on a computer system, and that Upper Field First (analog source) and Lower Field First (digital source) field types were primarily used for playback on DVD players hook-up to a TV set?

Thanks in advance for your clarification.

[Black Lab]

I have always used Lower Field First (w/my Sony Digital for my videos, and even when mixed with stills, plays fine on a TV.

[blplhp]

Jeff,

Exactly. I have always done the same, that's why Steve's answer confused me a bit.

And again, I would assume that using Lower Field First for a slideshow DVD is what is best if viewing the final product on a TV.

[Black Lab]

Now that I think about it, I have done one DVD that was exclusively a slideshow, (I'm sure) used LFF, and it played fine on a TV.

I would assume that using Lower Field First for a slideshow DVD is what is best if viewing the final product on a TV.

Like they say, "there's one way to find out".

[Trevor Andrew]

Hi

When you capture/transfer your video from cam-corder via firewire and select DV as the capture format, you have no property options to select.(other than DV-Type1)

What you have in the camera is what you get in the transferred files.
These are Dv-Avi ( it will be lower field)

If you select another capture format (mpeg-Dvd-Wmv etc) then you may change the capture settings,the video data is re-coded during capture.

With Dv-Avi you have no choice as to field order, being digital it will be Lower Field.

Field order for my slide shows reflects the order that I normally use for my video.

If I were to create a slide show with no video content then the order could be either, it would not matter. As my slide shows usually contain some video I stay with lower for digital.

Trevor

[sjj1805]

Don't confuse Digital Camera with Digital Camcorder.

Camera = still images - Frame based
Camcorder = moving images = Field based.

If your mixing still images (slide show) into a video then use the field relating to the video. Also in this situation apply anti-flicker.
Please view this post for details of how to apply Anti-Flicker
http://phpbb.ulead.com.tw/EN/viewtopic. ... 7309#87309

[PuzZLeR]

Greetings folks,

First time poster here although I've been reading for some time. I have learned an awful lot. Thanks!

I'm really clueless when it comes to this lower, upper and frame based stuff. What is this all about? Is there some informative link or tutorial regarding this that someone can post for me?

As well, I capture most of my video from my personal stand-alone DVR and dump it on my PC via DVD-RW for Ulead VS 10 to do its awesome edit magic.

Some of it is digital (recordings from TV and a digital satellite dish) and some of it is analog (VHS tapes I am converting). Then again, once it has been captured, isn't it all digital anyway? Maybe I missed the boat somewhere but if anyone can clarify I'd really appreciate it.

Then again, I've rendered, and re-rendered, certain video clips from upper to lower to upper, etc., at times not sure what I was doing. What's going to happen to these clips and what should I do about it?

Thanks so much in advance. You all rock!

[Black Lab]

Here's a general description - Fields and Frames.

[Ken Berry]

A little confusingly, the Field Order A in the Video Help explanation is Lower Field First in Video Studio (it was Field Order A up to and including VS8, though, and some other editing programs still use this terminology).

To take the explanation a little further, if simplistically, depending on the encoding method used, a half frame using Lower Field First (LFF) will, as the term implies, come first, then be followed by the other half frame. Another encoding system will have the upper half frame displayed first, and this is then called a field order using Upper Field First (UFF). But it is only after the micro-second involved in displaying both half frames that you have a complete frame displayed which your eye sees as a single frame.

But if you get the order around the wrong way, your eye will detect minor errors. You will get some jitter or straight lines during a panning shot will look jagged, even though a full frame is displayed. To correct the jitter or jaggies, you simply reverse the field order. If your video has been processed using LFF, then use UFF instead, or vice versa.

Generally speaking, video captured from an *analogue* source comes into your computer via some capturing device as a digital signal using UFF. If it comes from a mini-DV digital video camera, including one used for pass-through of analogue capture, it will almost invariably use LFF. But there are exceptions. A lot (all?) of mini DVD disc cameras, for instance, use UFF, as do some (all?) hard disc digital video cameras. Some higher end capture devices which are hardware encoded to capture analogue video, will use LFF instead of the more usual UFF for analogue capture. So you have to find out about this before you get too far into your editing.

Video Studio, like most editing programs, can handle UFF, LFF and Frame Based/progressive scan video with no problems. BUT -- and its a BIG 'but' -- any single project can only use one Field Order. Of course, you can have different projects on one DVD, and you can burn the separate projects using different Field Orders on one disc because if otherwise processed properly, they will be DVD-compliant regardless of whether they use LFF or UFF or Frame Based. But you can't have a single project which mixes video using both UFF and LFF.

As for slideshows, still images are already a single frame. They don't need the half frames to come together to display properly. They can thus use Frame Based properly. I know all the people above have said they use LFF (or sometimes even UFF) when doing slideshows or displaying still images as part of a larger video. I happen to use Frame Based for my slideshows (with anti-flicker switched on), though of course if I include photos in a video, then they take on the Field Order used by that particular video...

And at the end of the day, this does not matter. If a still image -- a single full frame, remember -- is displayed using LFF or UFF first, then each "half' frame is still a single frame displayed twice. So the end result is the same.

As a final comment, a computer monitor is quite different from a standard (analogue) TV. In effect it is similar to a digital TV which uses progressive scan. It can happily display Field Based and Frame Based video correctly (though you will still get jaggies etc if you use the wrong Field Order). An analogue TV, however, will have difficulty with video which started life as UFF or LFF video as opposed to a Frame Based still image. A progressive scan TV, on the other hand, because of the technology involved, will display Frame Based video properly, and in effect will convert a Field Based video signal on the fly to display properly as well.

Some analogue capture devices, including, as I understand it, the popular Adstech DVD Xpress DX2, uses Frame Based, or more correctly, progressive scan, as its scanning method because more and more people have progressive scan TVs. However, again as I understand it, once captured as Frame Based, it can be easily and successfully processed in Video Studio using a Field Order, and display properly on both analogue and digital TVs after being burned to DVD.

Here endeth the lesson...

[PeterHF]

It's been a while since I took this stuff in university but here's what I remember about interlaced video.

The whole idea about interlaced video is to handle motion as best as possible given the fact that the video stream is limited to 'painting' the entire screen 30 time a second. If you do this, the motion is quite jittery. So they came up with the idea to refresh the even lines and then the odd lines 60 times a second. You only refresh half the screen for each one of the passes but the overall effect is that motion looks better this way because of the combination of a certain amount of persistence on the screen and what your eye and brain does with the information.

It only takes a moment to realize that one must display the lines in the same order they are recorded. Suppose, for example, an object is moving across the screen from left to right at a constant rate therefore moving the same amount each 1/60 of a second and the video is captured upper frame first. Let's say that at time zero the object at position A. If we are capturing upper frame first then the first upper frame will show the object at position A. If the object moves X amount in 1/60 second, the first lower frame will show the object in position A + X and so on. The object's position will be as follows:

A (first upper frame)
A + X (first lower frame)
A + 2X (second upper frame)
A + 3X (second lower frame)

. . . and so on.

Now imagine if you played back this sequence lower frame first instead of upper frame first. You would have:

A + X (first lower frame)
A (first upper frame)
A + 3X (second lower frame)
A + 2X (second upper frame)

. . . and so on.

As you can see, you MUST play the video back in the same sequence it was shot or the motion will be very jittery.

To my knowledge, there is no way to changed the order of the original video without losing quality.

It is also important to realize that there is no complete image of the object at any given point in time so de-interlacing the image will necesarily reduce it's quality. Mind you, smart de-interlacing schemes can do a pretty good job of filling in the missing lines, you cannot get a perfect conversion.

[Ken Berry]

Thank you for the excellent and simply explained answer.

Re your last point, the latest progressive scan TVs appear -- at least to me -- to do more than just a "pretty good job" at conversion. To my perhaps tired old eyes, it seems perfect.

As far as I am aware, these TVs don't have any extra hardware just to process DVDs with Field Order, do they? Since just about every DVD of which I am aware will have one or the other Field Order, they need to have a very high order of quality in their conversion...

However, I am happy to acknowledge that I may have missed a point or two along the way (though not in your excellent explanation)...

[PeterHF]

Thanks Ken, for your kind words.

As far as progressive scan TVs are concerned, I'd have to read up them to shed any light on the subject, sorry. But you've sparks my interest. Perhaps I'll have something to say in the next couple of days.

Best regards,
Peter

[maddrummer3301]

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