Field Order A/B or Frame-Based?

astrovideo · Post by **astrovideo** » Thu Apr 26, 2007 3:28 am

Hi,
What is the difference between using Field Order and Frame-Based Frame Types? How do I know which one I should use when creating a disk from a file?

Thank you,
-Russ

Black Lab · Post by **Black Lab** » Thu Apr 26, 2007 3:33 am

The short answer is your project's field order should match your clip's field order. Digital video is primarily Lower Field (Field A), analog Upper Field (Field B). Frame-based is for computer monitors or progressive scan TVs (or slide show only projects).

Post by **Ken Berry** » Thu Apr 26, 2007 5:42 am

Just to expand very briefly on part of the short answer: digital video from a mini DV digital camera is normally Lower Field First, though from mini DVD and hard disk digital cameras it is normally Upper Field First.

astrovideo · Post by **astrovideo** » Thu Apr 26, 2007 2:25 pm

Is there a way I can examine my particular clip, and see what frame-type it is?

Thanks.

Ken Berry wrote:Just to expand very briefly on part of the short answer: digital video from a mini DV digital camera is normally Lower Field First, though from mini DVD and hard disk digital cameras it is normally Upper Field First.

Black Lab · Post by **Black Lab** » Thu Apr 26, 2007 2:36 pm

As previously stated, if you are using a Mini-DV or Digital8 camcorder then your field order is Lower Field (Field A). If you are capturing from an analog source, or if you are using a DVD or Hard Disk camera then it is usually Upper Field (Field B).

The only way to determine if you are correct is by burning a test to a DVD-RW. If the resulting DVD is jumpy when viewed on an interlaced TV, then you have the incorrect field order. If it plays smoothly then you guessed right.

astrovideo · Post by **astrovideo** » Thu Apr 26, 2007 3:22 pm

Thank you very much!

GeorgeW · Post by **GeorgeW** » Thu Apr 26, 2007 11:09 pm

The confusing thing is that some software will call Field-A (as upper field first), and Field-B as Lower field first. So if you are using other tools, you really have to know what they mean when they label their field order (Upper/Top is self explanatory, but Field-A/B or Odd/Even can get confusing...).

There are ways to determine your field order by using Virtualdub or other scripts in AVISYnth. You can do a search at videohelp.com for those types of tools to help determine your field order -- or as mentioned, burn to disc and see if you guessed correctly...

Regards,
George

Post by **Ken Berry** » Thu Apr 26, 2007 11:15 pm

George -- to add to the confusion, I think Field Order A is in fact Lower Field First!!!!

astrovideo: once you have captured a clip, then simply right click the clip within VS and select 'Properties'. That will normally tell you what Field Order is used on that particular clip. Once you know, you make sure all subsequent steps in editing and authoring maintain that same Field Order for a project involving that clip and others like it.

GeorgeW · Post by **GeorgeW** » Thu Apr 26, 2007 11:20 pm

Ken Berry wrote:George -- to add to the confusion, I think Field Order A is in fact Lower Field First!!!!

That's exactly my point, some software will treat Field-A as Upper (opposite Ulead's older software with the A/B designation). So unsuspecting folks might come here and read Field-A is Lower, but then go try something else and find out that Field-A is Upper...

Regards,
George

Post by **Ken Berry** » Thu Apr 26, 2007 11:27 pm

Ok -- sorry George, I hadn't quite seen the point you were trying to make.

But to add still more to the confusion, some programs don't even use the Upper/Lower or A/B terminology, but use Bottom and Top. GSpot is one such program which springs to mind!