FlipVertical and Cropping

[Seraphic-]

Is it "safe" to Crop and FlipVertical a video at the same time you deinterlace it? I thought it would save time doing them all at once, but would it cost quality? I mean, should I deinterlace first, and then Crop and FlipVertical after or does it matter?

[krieger2005]

To be secure do it after Deinterlacing.

[hanfrunz]

To be secure do it after Deinterlacing.
if you crop a even number of lines (2,4, etc) you will not have any problem, because you don't unintentionally swap the fields. You can crop as many pixels on the left and right as you want. (but try to be mod8 or mod16). If you crop first you will increase speed.

EDIT:
If you flip the image upsidedown you will change the fieldorder, so crop a odd number of lines before!
hanfrunz

[krieger2005]

And how is it with flipVertical()? In general the Fieldorder should change. Is there more to take care of?

[Guest]

If you deinterlace first, the video becomes progressive, so you can flip vertical without worrying about the field order change.

[krieger2005]

I understand the Question in that way, that Seraphic- ask, if he/she can use "FlipVertical" before Deinterlacing. In that way the order should be flipped also.

The other question for me is, if the deinterlacer would work also so good, when the video is flipped.

[Seraphic-]

Well, with my new capture card it seems I will no longer need to use "FlipVertical" as the video is no logner upside down.

Anyway, he as in I was cropping from 720x480 to about 632x444. So i'll just deinterlace first and crop after as I don't want any quality loss.