Interlace problem on fast movement in HDV at DVinfo.net

Joel L. Young · December 15th, 2007, 08:59 PM

I have a Sony A1U and I am using Vegas to capture. I find on fast movement there is a severe interlacing problem. I've added a link below to a picture of the problem. I capture as HDV and I thought since the field order is None (progressive scan) this shouldn't be a problem. This is probably something I should know how to fix, but since I don't I thought I would ask the experts. Anything anyone needs to know to help determine the problem just let me know.

http://thecritics.tv/Samples/InterlaceProblem.jpg

Eric Stemen · December 15th, 2007, 11:39 PM

I know in premiere you have to select de-interlace to make the footage look like it's really progressive. Selecting progressive still looks like interlaced when exporting. This is for premiere pro 1....I haven't messed with vegas so it could be different for that.

Jarrod Whaley · December 16th, 2007, 12:55 AM

If you shot interlaced, then it'll look interlaced no matter how you capture it... unless you deinterlace it in post, which unless I'm reading you incorrectly, you're not doing.

Are you seeing these same artifacts on an interlaced HDTV, or just on your progressive computer monitor? Interlaced footage played on a progressive monitor will always look like this, but it will look fine on an interlaced monitor. You actually have no problem if that's an accurate assessment of the situation.

If you do see these jaggies on an interlaced display, then that's different. Either your field order has gotten reversed, or your footage is all shifted over on the timeline by 1/60 of a second, or something like that.

So which is it?

Joel L. Young · December 16th, 2007, 12:26 PM

ok, let me see if I can provide you with the needed information...

I am shooting in 1080i, but I've never set interlaced or deinterlaced or any field options on the camera. I'm actually capturing in vegas to a 720 template, so I tried in the 1080 template, but still had the same problem, just thinner lines. I have not viewed this on an HDTV. I always post my stuff online. I use a HD divx when I post to stage6. You can see this problem in the HD divx, so I traced to back to the earliest detection possible and noticed there was a problem while capturing. Can't notice on the small viewfinder of the camera. I tried reversing the field order and did not notice a difference.

I'm posting a link to one of the videos, you can first notice around 20 seconds when he moves his hands. (you will need the divx player to view this)
http://www.stage6.com/The-Critics/vi...Critics-tv-(HD)

Ervin Farkas · December 17th, 2007, 09:54 AM

Joel, when processing interlaced footage to be viewed on a computer monitor YOU NEED TO DEINTERLACE! There is no ifs and buts, if you don't deinterlace, you will get the artifacts shown on your video. Some encoding software will do that automatically when encoding to a format destined for the internet, but others won't, you have to set it manually or do it before you encode.

One of the best pieces of software I found for deinterlacing (I use it for resizing as well) is the free VirtualDub (or VDub MPEG2 when working with HDV).

Joel L. Young · December 22nd, 2007, 11:00 AM

Thank you to everyone for your help. I've been away but will try as soon as I get back. Ervin, I will try that software out. Other parts of the video that are moving come out fine, so I am guessing if I use that software on my footage I should be fine. Again thanks everyone, I'll update with what I get.

December 15th, 2007, 08:59 PM	#1
Joel L. Young Regular Crew Join Date: Feb 2006 Location: Philadelphia, PA Posts: 55	Interlace problem on fast movement in HDV I have a Sony A1U and I am using Vegas to capture. I find on fast movement there is a severe interlacing problem. I've added a link below to a picture of the problem. I capture as HDV and I thought since the field order is None (progressive scan) this shouldn't be a problem. This is probably something I should know how to fix, but since I don't I thought I would ask the experts. Anything anyone needs to know to help determine the problem just let me know. http://thecritics.tv/Samples/InterlaceProblem.jpg

December 16th, 2007, 12:55 AM	#3
Jarrod Whaley Major Player Join Date: Jun 2006 Location: chattanooga, tn Posts: 721	If you shot interlaced, then it'll look interlaced no matter how you capture it... unless you deinterlace it in post, which unless I'm reading you incorrectly, you're not doing. Are you seeing these same artifacts on an interlaced HDTV, or just on your progressive computer monitor? Interlaced footage played on a progressive monitor will always look like this, but it will look fine on an interlaced monitor. You actually have no problem if that's an accurate assessment of the situation. If you do see these jaggies on an interlaced display, then that's different. Either your field order has gotten reversed, or your footage is all shifted over on the timeline by 1/60 of a second, or something like that. So which is it? __________________ -->jarrod whaley. www.oakstreetfilms.com

December 17th, 2007, 09:54 AM	#5
Ervin Farkas Inner Circle Join Date: Aug 2005 Location: Atlanta/USA Posts: 2,515	Joel, when processing interlaced footage to be viewed on a computer monitor YOU NEED TO DEINTERLACE! There is no ifs and buts, if you don't deinterlace, you will get the artifacts shown on your video. Some encoding software will do that automatically when encoding to a format destined for the internet, but others won't, you have to set it manually or do it before you encode. One of the best pieces of software I found for deinterlacing (I use it for resizing as well) is the free VirtualDub (or VDub MPEG2 when working with HDV). __________________ Ervin Farkas www.AtlantaLegalVideo.com

December 15th, 2007, 11:39 PM	#2
Eric Stemen Major Player Join Date: May 2004 Location: Louisville, KY Posts: 378	I know in premiere you have to select de-interlace to make the footage look like it's really progressive. Selecting progressive still looks like interlaced when exporting. This is for premiere pro 1....I haven't messed with vegas so it could be different for that.

December 16th, 2007, 12:26 PM	#4
Joel L. Young Regular Crew Join Date: Feb 2006 Location: Philadelphia, PA Posts: 55	ok, let me see if I can provide you with the needed information... I am shooting in 1080i, but I've never set interlaced or deinterlaced or any field options on the camera. I'm actually capturing in vegas to a 720 template, so I tried in the 1080 template, but still had the same problem, just thinner lines. I have not viewed this on an HDTV. I always post my stuff online. I use a HD divx when I post to stage6. You can see this problem in the HD divx, so I traced to back to the earliest detection possible and noticed there was a problem while capturing. Can't notice on the small viewfinder of the camera. I tried reversing the field order and did not notice a difference. I'm posting a link to one of the videos, you can first notice around 20 seconds when he moves his hands. (you will need the divx player to view this) http://www.stage6.com/The-Critics/vi...Critics-tv-(HD)

December 22nd, 2007, 11:00 AM	#6
Joel L. Young Regular Crew Join Date: Feb 2006 Location: Philadelphia, PA Posts: 55	Thank you to everyone for your help. I've been away but will try as soon as I get back. Ervin, I will try that software out. Other parts of the video that are moving come out fine, so I am guessing if I use that software on my footage I should be fine. Again thanks everyone, I'll update with what I get.