How can you capture even or odd fields ONLY?

[SirSolBadguy]

I want to capture video from a video game (F-Zero GX) witch runs in 60 UNIQUE fields per second. If I were to capture it at 320x240 it would look pretty blury when the action gets fast, because of the 60 fps. So I want to only capture even fields or odd fields, which would leave me with a perfectly crisp 29.97fps at 320x240, and should compress very well. I believe if I capture at 640x480, I could then remove half the fields myself, but my computer is slow and cannot capture at that high a resolution without dropping entire frames. So how can I do what I ask, in VirtualDub?

[FOO]

The obvious way is Avisynth
it has functions called SelectEven and SelectOdd
you probably can guess what they do.

Edit Sorry I didnt read your entire post. I think you have to
capture all the lines -> something x 480

You have to wonder what 320 x 240 actually does maybe it
discards every other field already

[Craig Tucker]

As Foo has alluded to if you capture with a vertical resolution of 240 vdub will only capture 1 field per frame.

[SirSolBadguy]

Yes I know how to do it after capturing it in 640x480. Here's my avs file on that:

#ASYNTHER Default (AVISource)
AVISource("C:\CAPTURE.AVI")
SeparateFields()
SelectEven()
LanczosResize(640,480)
Crop(34,15,-30,-17)
_2dcleanYUY2(0,5,2,3)
BicubicResize(448,336,0,0.5)
Convolution3d(1,8,8,8,8,3,0)

I'm just saying it would be a lot easier if I could just capture even fields only, from the very begining. That would save me the trouble of going though most of that code you see in the avs file. And also, when I capture at 640x480, it says it is using about 95% of my cpu, and every so often it drops frames. So that sucks...

Also to the other guy, I think you're mistaken. VirtualDub does not capture every other field if you cap at 320x240. It caps every field, but it downsizes them, correct? Because if it did only capture the even or the odds, then it wouldn't have such a motion blur look to it.

[Craig Tucker]

Other guy here.

This is an extract taken from virtualdubs website.

NTSC video is composed of alternating fields of 240 scanlines, and PAL/SECAM of 288. If you specify a height equal to or lower than that, the capture driver only snags one field. If you specify a taller image, both fields are grabbed. In either case when you specify a size smaller than the height of the field(s) captured, the result is then scaled down.

[SirSolBadguy]

0_o That's odd...then what could be causing the blurred frames when I cap at 240 lines? I assumed it was caused by the blending of the 2 unique fields for every frame.

[BJ_M]

its blurred because its low resolution ...

its a catch 22

[SirSolBadguy]

No, that is not the same kind of blur, moron. But nevermind anyways.

You are in breach of the forum rules and are being issued with a formal warning. Don't call moderator (or anyone) a moron..
/ Moderator BJ_M

[FOO]

Now that was sharp.

[BJ_M]

Now that was sharp.

but a little blurred around the edges i think ..









but wtf do i know ..

[Craig Tucker]

Good way to ingratiate yourself with the mods.