Quick fields clarification!….

[Barend Onneweer]

If you’ve got a couple of minutes, I wrote an article about the options years ago:

https://library.creativecow.net/articles/onneweer_barend/deinterlacing.php

It’s old, but most of it still stands.

For de-interlacing your best bet is still FieldsKit. Magic Bullet does a great job, too – but renders slower.

Bar3nd

Raamw3rk – digital storytelling and visual effects

[Kevin Camp]

[Jimmy Brunger] “I’ve done the drop into comp>set comp fr rate to 50fps and stepped through using each diff variant of interpret footage…It appears to not have fields, as every other frame is static. However, when I change the field separation there is a slight shift on the image. Have I got this right – if footage is progressive in it’s origin or deinterlaced then changing interp footage shouldn’t make any difference to the image? So why is this footage looking different? Also, part of the image look a bit ‘torn’ and jaggy no matter how you interpret it..does this mean it’s been poorly deinterlaced?”

if you see every other frame is a duplicate when you double the frame rate in a comp (and no frame blending is applied) then the footage is progressive. the shift you see when changing the field separation settings is probably due to the incorrect setting of separating fields for that footage (incorrectly choosing to separate fields will degrade the image). the torn, jaggy look of some footage despite the settings sounds like poor deinterlacing, as you thought.

[Jimmy Brunger] “If anything DOES have fields I want to combine the fields so everything I have is progressive (don’t want to be doing any interlaced renders) so do I need something like Re:Vision’s FieldsKit or will just separating fields and rendering progressive yield good results? I always thought that if you render separated footage progressively then you only get half the information?…though I have read elsewhere on the cow that AE still renders both fields, but both at the same time? Surely if that was the case there would be no need for something like FieldsKit…”

not to steer you away from a good plugin like fields kit, but you can get ae to utilize the fields that are being ‘thrown away’ by enabling frame blending (frame mix, not pixel motion). when the fields are separated correctly, ae will deinterlace both sets of fields and blend the two resulting progressive frames together to make one frame. you may still get some artifacts from the interlacing, but you might give it a try to see how it works on your footage. sometimes enabling the preserve edges option in the interpret footage window can help the edge artifacts.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Jimmy Brunger]

Thanks guys. Looks like this piece of footage has been badly interlaced before I got it then..I’ll just have to live with it. Will try the Frame Mix thing on a progressive sep render and see how it comes out. FieldsKit is really cheap though, so might give that a go aswell

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