-
Deinterlacing?
I am curently working with some interlaced (50i) footage that I want to ‘amalgamate’ the fields to make whole progressive frames. I know our Quantel Editbox can do this natively, but I can’t work out an effective way to do this in AE. Obioucly I can separate fields and render it out progressively, but that halfs my resolution. I want the progressive/film look, but also want to retain the full res of the shots.
I watched Andrew’s deinterlace tutorial and I may be being really thick here, but is that truly combining the fields? It seems to only be using the upper field and then duplicating it and blurring..how can I use both fields?
This is with regard partly to a thread I started yesterday about interlaced footage taking twice as long to render as progressive: https://forums.creativecow.net/readpost/2/910666?
Any help REALLY appreciated.
*Production Studio Premium / *Combustion 3
————————————-
Win XP Pro SP2 / Intel P4 3GHz / 2GB RAM / GeForce FX5200 / DeckLink Pro / Roland DS-5 monitors / Sony BVM-20G1E / DVS SDI Clipstation / 110GB boot/80GB media/600GB RAID-0 -
2 Replies
-
i’m assuming this is in regards to the producer who wanted to shoot 50i to get 25p…?
i realy think he/she needs to decide what they want in the end. if they want the ‘filmy’ look of 25p in the end, they really should shoot 25p from the begining. the footage will look better…. any thing you do inpost to create 25p from 50i will involve interpolation, and interpolated pixels are never a good as a shot pixel.
other things happen when you try to doo this, too… you r shutter angle (or shutter speed) will look tighter, twice as tight as normal. if you said that normal shutter angle is 180, the 50i-25p will look 90 (shooting interlaced essentially shoots 2x shutter speed as progressive), so you will have less motion blur to your shot footage with converted 50i than you would have with real 25p, and its hard to get that back, even with frame blending and interpolating plugins liek reelsmart motion blur.
so here’s all the processing that the footage may have to go thru to get 25p out of 50i… first, generate (or interpolate) half the vertical resolution for each frame. second, use frame blending to composite the interploated frames from the other set of fields on to your first frames from you first set of fields. lastly, you’ll probably be adding some motion blur for a natural looking shutter speed with reelsmart motion blur, which will be interpolating the movement of pixels to generate your final frames. nearly all your pixels have now been interpolated, and they jsut can’t be as clean as the original pixels.
but, if they want the smoothness of 50i, leave it 50i. you’ll need to separate fields for effecting, but render back to fields in the end. it will take 2x longer (as you found) due to ae needing to calculate 2x the frame rate to get the extra field data, but everything will be very smoooth and clean.
to shoot interlaced to get progressive is just silly.
Kevin Camp
Designer – KCPQ, KMYQ & KRCW -
Hi guys,
Thanks for the responses! No, this is for another job where I personally wanted to try avoid render time by deinterlacing and rendering progressive – but a no go it seems. Can’t believe I didn’t know about AE’s ‘problem’ of taking twice as long for interlaced. Do other compositors have the same restriction? The Editbox will render either and amalgamate on the fly in the same time – I know it’s an expensive box, but I thought AE would have caught up in certain respects…I mean I know I need a much faster machine, but under the hood I’m surprised. Hey ho.
No Moldy, the ‘shooting 50i to get 25p’ guy is still a plonker and is still talking tosh. But that job didn’t come off in the end anyway unfortunately, so maybe the client thought he was full it aswell!
We might have to invest in Magic Bullet in the future then (and a faster box of course!) I just wanted to see if I could offload some work from the E/box, but obviously not for stuff like this! My keying tools are still head and shoulders above the Quantel though, so I might see some of the job, other than the very pedestrian GFX I get lumbered with!
It’s all work…
*Production Studio Premium / *Combustion 3
————————————-
Win XP Pro SP2 / Intel P4 3GHz / 2GB RAM / GeForce FX5200 / DeckLink Pro / Roland DS-5 monitors / Sony BVM-20G1E / DVS SDI Clipstation / 110GB boot/80GB media/600GB RAID-0
Reply to this Discussion! Login or Sign Up