11 Replies Latest reply on Mar 22, 2009 8:41 PM by Jim_Simon

    Is this an interlacing problem? Screenshots included.

      Hi i'm wondering if someone could point out an error in my workflow and settings. To best explain it I made a webpage that has screen shots of each step and the end outcome which I believe to be an interlacing issue.

      so here's the web url
      http://www.albertoh.com/misc/Question.html

      Any help would be greatly appreciated.

      Thank you in advance.
        • 1. Re: Is this an interlacing problem? Screenshots included.
          Bill Seper Level 1
          My version of Premiere is a few years old, so there are some settings I'm not sure of, but I also don't understand what you're saying on the web page notes. Your camcorder can shoot at 24P, but you say, "Notice the frame rate at 29.97 which I believe the camera shoots at". Yet you set your project to operate at 24P? You lost me there. Is your footage 24P or 30P or 60i? From the screen cap you showed at the bottom it certainly looks interlaced as though it were shot at 60i. If so, why are you setting your project at 24P to begin with? Are you trying to take 60i footage and edit at 24P in hopes of converting it to 24P in the process? That won't work too well. If you shot it at 60i, then set your project to 60i. Always edit at the same frame-rate and type (interlaced or progressive) that you shot at. Now if you want to take your finished 60i movie after you're done and then convert it to 24P there are products like Magic Bullet and DV Film Maker that can do that for you. Obviously it won't be quite as good as shooting at 24P to begin with, but they get reasonably good results.
          • 2. Re: Is this an interlacing problem? Screenshots included.
            Level 1
            I used scenefile f6 which is 24pa on my dvx camera. So I know I shot it in 24pa, however my understanding is that the camera will add extra frames when it records to tape to make it 29.97. It flags these frames in the firewire data stream which editors like FCP and Premiere should be able to read and remove those frames during the 2:3:3:2 pulldown. This would effectively then conform the footage back to 23.98.
            • 3. Re: Is this an interlacing problem? Screenshots included.
              Dan Isaacs Level 2
              I am not sure, but have you tried setting the field order to upper or lower? Perhaps PPro needs to know the original field order of the pulled-down material in order to remove the pulldown.
              • 4. Re: Is this an interlacing problem? Screenshots included.
                Bill Seper Level 1
                "...my understanding is that the camera will add extra frames when it records to tape to make it 29.97."

                Oh yeah, my bad. I don't have a 24P cam myself, but I do remember reading something about that.
                • 5. Re: Is this an interlacing problem? Screenshots included.
                  creig bryan-mUOxt4 Level 1
                  Er, ah, is that you Jim? (smile). Er, (smile), that is...

                  Keep Smiling
                  • 6. Re: Is this an interlacing problem? Screenshots included.
                    Jim_Simon Level 8
                    I would not expect to see that kind of interlacing on a freeze frame. My best guess is that you did actually shoot in 24p, not 24pA.

                    Despite Adobe's claim that a 24p sequence can be used for both, what I understand of the two processes is that pulldown cannot be correctly removed from normal 24p footage (which is why 24pA was invented in the first place). So trying to use 24p footage in a 24p sequence might very well explain what you're seeing.
                    • 7. Re: Is this an interlacing problem? Screenshots included.
                      Level 1
                      i'm 100% positive that I shot the footage in 24pa unless my dvx is defective.

                      I haven't tested this out but perhaps instead of using the 24p preset I should use the 29.97 sequence in order to interpret the 23.98 footage properly. I know that in other editors like FCP if you start with a capture 23.98 frame rate and do the 2:3:3:2 pulldown it will randomly delete frames to get from 29.97 to 23.98. So the end result would be random progressive frames deleted while some interlace frames are still mixed in.

                      Fact is, there is definite interlacing which is causing the horizontal displacement and short of starting over with another editor, i'm not sure what to do.

                      I tried to even do some testing and capture some test footage last night, but I couldn't get the capture to recognize my dvx. Instead my built in webcam kept turning on. Very frustrating.
                      • 8. Re: Is this an interlacing problem? Screenshots included.
                        Level 1
                        So after thinking about it some, I'm thinking that since the footage was captured via onLocation and not through tape and firewire, the DVX flags that mark the 3:2 pulldown frames are no longer applicable. Thus trying to properly remove the pulldown in premiere is impossible cause the flag information is no longer there.

                        My guess is that onLocation is only good for when you're not shooting 24p or 24pa.
                        • 9. Re: Is this an interlacing problem? Screenshots included.
                          Jim_Simon Level 8
                          Very possible. I've only ever used OnLocation for standard 30i footage myself.
                          • 10. Re: Is this an interlacing problem? Screenshots included.
                            Curt Wrigley Level 4
                            I would try capturing a segment directly to a 29.97 preset. Looks like you're adding pull down twice.

                            But; at 24frames there is an inherit problem with "big pans". Pans must be done slowly at that frame rate.
                            • 11. Re: Is this an interlacing problem? Screenshots included.
                              Jim_Simon Level 8
                              That's true, but the issue then is usually one of motion blur, not interlacing.