De-interlace advice at DVinfo.net

Dan Brockett · January 13th, 2008, 04:34 PM

Hi all:

I am finishing up an edit for a project that was shot on two DVX-100a camcorders. Mini DV obviously. One was shot 30p and it appears that the second angle was shot interlaced. Cutting between the two looks rather strange as one angle has the softer progressive look from the 30p, while the other angle looks "live".

I want to de-interlace the interlaced camera angle to get the clips to match better. When I apply FCP's de-interlace filter, the overall look is closer but I notice pretty nasty aliasing with stair-stepping. Didn't there used to be a trick with duplicating the video track, then applying the de-interlace filter to both, one with upper field order first, then one with lower, then combining them somehow? Is this ringing a bell? Are there other, better ways to de-interlace without going out to Compressor? This show has a ton of clips and everything is already cut so I would rather not have to take all of the clips out of FCP, if possible. Any advice for me? Someone mentioned that DVDSP has a de-interlace feature so in theory, when the client authors the DVD, he could de-interlace? Would that mess up the 30p clips though since they are already de-interlaced?

G5 Dual 2.3
4GB RAM
FCP 5.1.4
QT 7.2
DV material
Final output DVD

Thanks,

Dan

Aric Mannion · January 15th, 2008, 10:33 AM

I may be totally wrong here, but I would really test this out on a DVD before you go de-interlacing!!
DVDs are interlaced and if you go ahead and de-interlace, the dvd process will interlace it again, and your quality may drop from the process. I understand the 30p looks different, but I'm pretty sure all SD DVDs have to be interlace.
Am I wrong about this?
See how different it looks on the DVD, don't go by the timeline. Also if it were me, I would try shooting with the shutter speed on 30 in the future, that may make the interlaced video look less "live".

Dylan Pank · January 16th, 2008, 01:18 PM

Dan, what you're looking for is a blend de-interlace. The process you're talking about is a manual blend de-interlace, called something like "real sex" or something similarly daft. Try the (free) Too Much Too Soon FCP filters - there is a good de-interlace filter in there with a ton of options.

And I'd avoid the 30/s shutter speed unless you like overly blurry movement.

January 13th, 2008, 04:34 PM	#1
Dan Brockett Inner Circle Join Date: Feb 2006 Location: Los Angeles, California Posts: 2,109	De-interlace advice Hi all: I am finishing up an edit for a project that was shot on two DVX-100a camcorders. Mini DV obviously. One was shot 30p and it appears that the second angle was shot interlaced. Cutting between the two looks rather strange as one angle has the softer progressive look from the 30p, while the other angle looks "live". I want to de-interlace the interlaced camera angle to get the clips to match better. When I apply FCP's de-interlace filter, the overall look is closer but I notice pretty nasty aliasing with stair-stepping. Didn't there used to be a trick with duplicating the video track, then applying the de-interlace filter to both, one with upper field order first, then one with lower, then combining them somehow? Is this ringing a bell? Are there other, better ways to de-interlace without going out to Compressor? This show has a ton of clips and everything is already cut so I would rather not have to take all of the clips out of FCP, if possible. Any advice for me? Someone mentioned that DVDSP has a de-interlace feature so in theory, when the client authors the DVD, he could de-interlace? Would that mess up the 30p clips though since they are already de-interlaced? G5 Dual 2.3 4GB RAM FCP 5.1.4 QT 7.2 DV material Final output DVD Thanks, Dan

January 15th, 2008, 10:33 AM	#2
Aric Mannion Major Player Join Date: Apr 2006 Location: Boston, Massachusetts Posts: 616	I may be totally wrong here, but I would really test this out on a DVD before you go de-interlacing!! DVDs are interlaced and if you go ahead and de-interlace, the dvd process will interlace it again, and your quality may drop from the process. I understand the 30p looks different, but I'm pretty sure all SD DVDs have to be interlace. Am I wrong about this? See how different it looks on the DVD, don't go by the timeline. Also if it were me, I would try shooting with the shutter speed on 30 in the future, that may make the interlaced video look less "live".

January 16th, 2008, 01:18 PM	#3
Dylan Pank Major Player Join Date: Nov 2004 Location: Portsmouth, UK Posts: 611	Dan, what you're looking for is a blend de-interlace. The process you're talking about is a manual blend de-interlace, called something like "real sex" or something similarly daft. Try the (free) Too Much Too Soon FCP filters - there is a good de-interlace filter in there with a ton of options. And I'd avoid the 30/s shutter speed unless you like overly blurry movement.