3 Replies Latest reply on Sep 5, 2007 8:10 AM by Steven L. Gotz

    Help pixel aspect ratio and interlacing issues.

      I get CS3 Master's Collection tomorrow so I am getting ready to do a lot of editing.

      I have the most trouble when I combine different formats such as:

      -Square vs Rectangular Pixel Aspect Ratios
      -Different Size videos (720x480; 640x480; 480x360)
      -Interlaced and Non-interlaced Elements

      I have a thought about work flow using Photoshop, Premiere, and After Effects that I would love your comments on.

      I shoot in NTSC DV (720x480) (.9) and output for viewing on the web. I constantly have trouble with square and rectangular pixels and also with interlacing.

      So, I thought: "What if I were to convert all of my DV clips to 640x480 (square pixels) right away and then edit like that?" I could convert it with a lossless codec and still edit in an uncompressed format; and I would have fewer problems when moving clips to Photoshop and After Effects, or when importing square pixel elements into Premiere that I created in AE.

      I have read a lot of stuff on interlacing and pixel aspect ratio issues, but I seem to struggle a lot and waste most of my brain power on the "mathmatics" of it all.

      Can some of you give me any ideas? How do you run your workflow?


      -Mike Behrens-
        • 1. Re: Help pixel aspect ratio and interlacing issues.
          Steven L. Gotz Level 5
          Do not attempt to edit in a non DV format. The software is specifically designed to work better with DV AVI at 720X480.

          When it is time to export for the web, decide on Flash, Windows Media or Quicktime. When you export use square pixels at 640X480, or more commonly, 320X240.When you export, the Adobe Media Encoder will deinterlace for you.

          Photoshop can handle a 720X480 image with 0.9 PAR. No problem. So can After Effects.

          Edit in 729X480 and export to anything you want.
          • 2. Re: Help pixel aspect ratio and interlacing issues.
            Level 1
            Thank you, Steven, for your reply.

            I have read your articles on www.creativecow.net and quite a bit of stuff on your web site.

            So, let's say I create an After Effects or Photoshop element at 720x480 with a .9 PAR; I then bring it over to Premiere, finish editing my video, and output it @ 640x480-Square PAR and deinterlacing checked using Adobe Media Encoder.

            I know the video clips will deinterlace properly, but won't Premiere try to deinterlace the non-interlaced AE & PS elements thereby making them interlaced in the final output.

            btw... I plan to use flash as my output for the web, but I think all of the basic concepts here apply.

            Thanks again for your help,

            -Mike Behrens-
            • 3. Re: Help pixel aspect ratio and interlacing issues.
              Steven L. Gotz Level 5
              If you have a lot of non-interlaced media, then I suggest deinterlacing your video elements before you export, and uncheck the default deinterlacing in the Adobe Media Encoder.

              Just right click on each clip and under Field Options select "Always Deinterlace".

              However, you might want to just try mixing the two in a sample export first, before you go to that trouble.