Field order

[zoobie]

Is there a way to double check the field order of a cap?
Didn't see a tool...
No problems...just want to see for myself.
Thx

[jimmalenko]

There used to be a guide in the guides section here, but I cannot seem to locate it.

[thecoalman]

99.9% of the time it depends on the capture source. DV devices are BFF, capture cards are TFF.

http://www.videohelp.com/forum/viewtopic.php?t=257631

[zoobie]

Yes...I noticed that.

I guess it's included with most editors
People have the fields mixed up
Perhaps a tool to make this clear would help

[jimmalenko]

Ya-ha .... found what I was looking for earlier.


http://forum.videohelp.com/viewtopic.php?t=194728

[manono]

No offense, but I don't find that thread to which you linked helpful at all. Well, fmctm1sw had it right, but he was too terse, and was ignored anyway. If you have AviSynth installed, then, quoting from the DecombTutorial.html:

To determine the field order, make an Avisynth script that serves the raw clip without any processing. If it were an AVI, then just AviSource() would be used. For our examples, we'll use AviSource(). Add a script line to separate the fields using top field first, as follows:

AviSource("C:\Path\To\Video.avi")
AssumeTFF().SeparateFields()

Now serve the script into VirtualDub and find an area with motion. Single step forward through the motion. Note whether the motion progresses always forward as it should, or whether it jumps back and forth as it proceeds. For example, if the field order is wrong, an object moving steadily from left to right would move right, then jump back left a little, then move right again, etc. If the field order is correct, it moves steadily to the right.

So, if it plays smoothly, your clip is TopFieldFirst (TFF), and if it jumps back and forth, it's BottomFieldFirst (BFF).

If it's a vob or mpg, then you use MPEG2Source after making a D2V project file using DGIndex:

MPEG2Source("C:\Path\To\Video.d2v")

[jimmalenko]

No offense, but I don't find that thread to which you linked helpful at all.

Are you talking to me ?

[manono]

Yeah. I understand this stuff, and I found all the discussion and contradiction nothing but confusing. Besides, not everyone uses TMPGEnc. By the same token, not everyone uses AviSynth, but, in my opinion, at least for something like this, as well as for many other things, they should.

[jimmalenko]

Yet ironically the method as described essentially is doing the same thing (removing one entire field) ?

[manono]

I'm one of those that doesn't use TMPGEnc, but no, the AviSynth method isn't removing one of the fields. What it's doing is splitting the video into its component fields, and assigning one of them to play first (TFF, in the example). So, following that script, if the source was 720x480 and 29.97fps, the script will give you a video of 720x240 and 59.94fps. If you play it and it plays smoothly, it really is TFF. If you play it and it plays jerkily, it's really BFF. And if you then replace AssumeTFF() with AssumeBFF() and play it, it should play smoothly. It's foolproof and, based only on what I read in your link, and remembering back to my TMPGEnc days so many years ago when I needed it for IVTC, the AviSynth method for determining field order is also easier.

Oh, and I forgot to mention, if your source is a vob or mpg, you open it in DGIndex and run the Preview. The Information screen that opens up will immediately tell you the field order.

[zoobie]

I see it in TMPGEnc now...the default wizard threw me off.

My neighbor got a high speed connection and a dvd burner. He doesn't do video but grabbed all these aps and handed them to me on 2 data discs. Old versions of Vegas, Pinnacle, TMPGEnc, Vdub, tons more. I'm only now going thru them because I haven't needed anything.

[jimmalenko]

but no, the AviSynth method isn't removing one of the fields.

Sorry, bad choice of words.

It's foolproof and, based only on what I read in your link, and remembering back to my TMPGEnc days so many years ago when I needed it for IVTC, the AviSynth method for determining field order is also easier.

Yeah, possibly. I am just the messenger though after all.

Although learning to script isn't exactly the easiest for the type of people who don't know what their field order is. Personally it really doesn't bother me, as I know what I'm getting, every time

[jagabo]

Although learning to script isn't exactly the easiest for the type of people who don't know what their field order is.

Put this AVISynth script in VirtualDubMod's Template folder as TestTFF.AVST:

#ASYNTHER TestTFF
[DirectShowSource("%f")]
AssumeTFF()
BOB()

When you open a file with VirtualDubMod use the "Use AVISynth Template" pulldown at the bottom of the Open Video File dialog to select the TestTFF template. Now you don't have to write a script every time you want to test.