View Full Version : Interlaced or Progressive Clip - How to Tell?


Matthew Weitz
April 23rd, 2005, 02:56 PM
Hi. I'm new to digital video editing.

I currently use Adobe Premiere 6.02.

Is there a way to determine if a clip I'm working with is interlaced or progressive? Like I have a few .avi and .mpg files, and I want to know if they were filmed with a camera that had its settings on interlaced or progressive.

Boyd Ostroff
April 23rd, 2005, 04:02 PM
Pick a section of the video that has some kind of fast motion, like a person running, a car passing, etc. Look at a few still frames in your NLE. If it's interlaced it should be very obvious, the edges of moving objects will have a comb effect where each of the 60i fields were captured. If it's true progressive you will see a blurred image in the moving parts, but the edges won't have the comb effect.

Have a look at this site for some examples: http://www.100fps.com/

Matthew Weitz
April 24th, 2005, 03:19 PM
Thanks.
What does NLE stand for?

Brandon Greenlee
April 24th, 2005, 07:48 PM
From DVDictionary:

NLE - Non-Linear Editing

non-linear – computer-based editing which permits video clips, sound, edits or special effects to be removed, replaced, moved or modified at any time without changing or overwriting the original clip.

Boyd Ostroff
April 24th, 2005, 08:00 PM
What does NLE stand for?In your case... Adobe Premiere 6.02 :-)

Matthew Weitz
April 26th, 2005, 07:59 PM
I think I got it. I used the following technique to deinterlace my clips (Adobe Premiere 6.02):

- I select the clips in my timeline.
- I choose Clip > Video Options > Field Options
- I select Always Deinterlace
- I click OK.

Do you know if there is a better way?

My end result is to get a good quality DVD.

Christopher Lefchik
April 26th, 2005, 09:14 PM
Mathew,

Is there a particular reason you are deinterlacing your clips? You will lose quality by deinterlacing them. Usually the only reason you deinterlace video is to remove stuttering, or if you are striving for a "film look." But since you are removing one of the two fields from the video frame you will lose half of your resolution, which will be particularly apparent in interlaced (non-progressive) video.

If the video was filmed in progressive mode there is no need to deinterlace. It will already have the flicker associated with film.

Rob Lohman
April 30th, 2005, 03:37 AM
Christopher: the max resolution drop (in theory) is indeed 50%. HOWEVER,
with todays more advanced algorithms the drop shouldn't be so bad. To simply
proclaim you loose half the resolution is incorrect in my opinion.

(the following piece is not targeted to anyone specific, but just my feel
on some of the technical details people can get hung up on!)

Personally I don't even care, even if I did loose 50% resolution. I care how
the end result looks and how well the movie has been crafted together
(story, visuals, editing, music, sound effects, acting etc.), not how many
"lines" of resolution it has.

Christopher Lefchik
April 30th, 2005, 07:40 AM
Christopher: the max resolution drop (in theory) is indeed 50%. HOWEVER, with todays more advanced algorithms the drop shouldn't be so bad. To simply proclaim you loose half the resolution is incorrect in my opinion.
Well, that's good to know. But would that apply to the software he is using, Premiere 6? It's over five years old now.

I do know that from my own experience with a project I rendered out of After Effects (version 5.5, I believe), where my source was interlaced and my render settings were for deinterlaced, that there was a definite loss in quality. Sure, it had the filmic "flicker," but very unfilmic digital jagged edges.

Matthew Weitz
April 30th, 2005, 01:18 PM
Mathew,

Is there a particular reason you are deinterlacing your clips? You will lose quality by deinterlacing them. Usually the only reason you deinterlace video is to remove stuttering, or if you are striving for a "film look." But since you are removing one of the two fields from the video frame you will lose half of your resolution, which will be particularly apparent in interlaced (non-progressive) video.

If the video was filmed in progressive mode there is no need to deinterlace. It will already have the flicker associated with film.

I was under the mistaken assumption that I wouldn't lose any quality.

Gotcha. Thanks.