Deinterlacing Fast Motion Footage at DVinfo.net

September 29th, 2007, 07:04 AM

I've got some footage that I've sped up. That track has a Mike Crash deinterlacer on it - however when I output the sped up footage, it appears interlaced. Is there a way around this?

I'm guessing it needs to deinterlace AFTER being sped up but how do I do this, since the velocity isn't an FX that I can put in a certain order...

Gian Pablo Villamil · September 29th, 2007, 08:15 AM

No, it's the opposite. You need to deinterlace the footage first at its regular speed, then apply a velocity change to the now-progressive footage.

This is because the process of speeding up will drop frames, and those missing frames contain information that the deinterlacer needs.

Fortunately, it is very easy to set this up in Vegas:

1) Load your media
2) Apply the MC Smart Deinterlacer
3) At the bottom of the Video Event FX dialog, look for the little timeline
4) There should be the text "Smart Deinterlacer" with a little triangle just to the left of it
5) Click on the triangle - it should flip over to point the other way (sharp end towards the left)
6) Apply your velocity changes, other effects, etc.

The little triangle is called the pre/post toggle, and is used to set whether effects are applied before or after the rest of the rendering process.

Any effects that should be applied to raw frames should be "pre", before Vegas does any kind of frame rate change or interpolation. Deinterlacing and noise reduction are in this category.

September 29th, 2007, 09:07 AM

ahh right, so for example, for reducing combing when zooming in on footage, you would deinterlace PRE, (pointing to the left), so that it's a progressive frame, then it zooms in on that... rather than zooming in on it, creating the combing FIRST then attempting to deinterlace it

correct?

thanks

Gian Pablo Villamil · September 29th, 2007, 11:35 AM

Exactly.

It's practically impossible to remove combing once you've scaled the video - deinterlace filters are looking for alternating single pixel lines.

Quote:

Originally Posted by Jonny Brady

ahh right, so for example, for reducing combing when zooming in on footage, you would deinterlace PRE, (pointing to the left), so that it's a progressive frame, then it zooms in on that... rather than zooming in on it, creating the combing FIRST then attempting to deinterlace it

correct?

thanks

September 29th, 2007, 11:39 AM

hmm, well perhaps you can help me with this? 'cause that's not working for me...

http://www.dvinfo.net/conf/showthrea...=104451&page=2

Gian Pablo Villamil · September 29th, 2007, 11:53 AM

Just posted in that thread too.

Make sure you're using either the Mike Crash filter OR Vegas built-in deinterlacing, not both.

September 29th, 2007, 07:04 AM	#1
Guest Posts: n/a	Deinterlacing Fast Motion Footage I've got some footage that I've sped up. That track has a Mike Crash deinterlacer on it - however when I output the sped up footage, it appears interlaced. Is there a way around this? I'm guessing it needs to deinterlace AFTER being sped up but how do I do this, since the velocity isn't an FX that I can put in a certain order...

September 29th, 2007, 08:15 AM	#2
Gian Pablo Villamil Regular Crew Join Date: Mar 2006 Location: New York, NY Posts: 138	No, it's the opposite. You need to deinterlace the footage first at its regular speed, then apply a velocity change to the now-progressive footage. This is because the process of speeding up will drop frames, and those missing frames contain information that the deinterlacer needs. Fortunately, it is very easy to set this up in Vegas: 1) Load your media 2) Apply the MC Smart Deinterlacer 3) At the bottom of the Video Event FX dialog, look for the little timeline 4) There should be the text "Smart Deinterlacer" with a little triangle just to the left of it 5) Click on the triangle - it should flip over to point the other way (sharp end towards the left) 6) Apply your velocity changes, other effects, etc. The little triangle is called the pre/post toggle, and is used to set whether effects are applied before or after the rest of the rendering process. Any effects that should be applied to raw frames should be "pre", before Vegas does any kind of frame rate change or interpolation. Deinterlacing and noise reduction are in this category.

September 29th, 2007, 09:07 AM	#3
Guest Posts: n/a	ahh right, so for example, for reducing combing when zooming in on footage, you would deinterlace PRE, (pointing to the left), so that it's a progressive frame, then it zooms in on that... rather than zooming in on it, creating the combing FIRST then attempting to deinterlace it correct? thanks

September 29th, 2007, 11:39 AM	#5
Guest Posts: n/a	hmm, well perhaps you can help me with this? 'cause that's not working for me... http://www.dvinfo.net/conf/showthrea...=104451&page=2

September 29th, 2007, 11:53 AM	#6
Gian Pablo Villamil Regular Crew Join Date: Mar 2006 Location: New York, NY Posts: 138	Just posted in that thread too. Make sure you're using either the Mike Crash filter OR Vegas built-in deinterlacing, not both.