0 Replies Latest reply on Oct 30, 2013 5:38 PM by Guy Burns

    How to remove extra frames?

    Guy Burns Level 1

      This is more a technical exercise than anything else. I have chosen a Tupperware commercial (38.6 MB, MPEG2) as my test file: https://archive.org/details/tupperware_2


      I'd like to know what's going on with this file.



      Image Size

      Quicktime reports the file as: MPEG2 muxed, 320 x 240, 29.97 fps, PAR =1, 4069 kbps. QT plays it as described. i.e. a landscape-type image, 320 x 240.


      MediaInfo and MPEG Stremclip report the file as MPEG2, 352 x 480, 4:3, 29.97 fps, interlaced, bottom field first.


      Premiere reports the file as 352 x 480 (1.8182), 29.97 fps, LFF. It sees the file as (352 x 1.8182) x 480 = 640 x 480.



      Interlaced or Progressive?

      When I step through the video in QT or Premiere one frame at a time, I can see no evidence that this video is interlaced. i.e. I was expecting to see slightly blurred images regularly as the 3:2 pulldown came into play. But no, as I step through the video it seems to be to be progressive.


      This is what I think has happened to this video. Please feel free to point out any errors.


      1. In 1961 this video was shot at 24.000 fps on film.
      2. At some stage it was converted to 29.97i  for showing on USA television, but that is not the version I am seeing here.
      3. At some other time the original film (24 fps) was converted to 29.97p by doubling up five film frames every second so that the original 24 become 30. i.e. ABCDEE FGHIJJ KLMNOO PQRSTT UVWXYY



      Ques 1

      What is the technical name for adding frames in the way described above?


      Ques 2

      How can the extra frames be removed? It should be as easy as selecting the first frame and then asking the software to automatically remove frame 6, 12, 18, 24, 30 to get back to the original. What software can do that?


      Ques 3

      If the file is progressive, why is it reported as interlaced?