4 Replies Latest reply on May 30, 2010 6:46 PM by Jeff Bellune

    Scaling 720p to NTSC DVD Widescreen

    MarkCohenDev

      Premiere Pro CS5

       

      I have 1280x720p24 footage (square pixels) that I would like to put on a DVD in widescreen format.

       

      I create a 720x480 sequence with a widescreen 16:9 pixel format.  Great, because scaling 1280x720 to 720x480 and stretching the image to 16:9 should maintain the original display aspect ratio (1280/720 == 16/9 and 853.3r/480 == 16/9).  Except it doesn't in Premiere.

       

      It scales the 720p footage too much horizontally, leaving black bars on each side, so that when the resulting DVD video is played, the 16:9 image (now approximately 854x480 pixels, or a 16:9 display aspect ratio) contains my footage skewed to something less than 16:9.  I realize that this is probably because premiere uses the pixel-aspect-ratio based on a 704x480 resolution scaled to 16:9 image, but it's a poor way to handle 16:9 video for a 720x480 frame.

       

      How are other people handling this problem?  It seems silly for me to have to manually create 704x480 video when 720x480 should handle this footage fine.  And it also seems silly for me to have to manually scale my 720p footage to fill the entire 720x480 frame rather than premiere doing it automatically.

       

      one.jpg

        • 1. Re: Scaling 720p to NTSC DVD Widescreen
          Jeff Bellune Adobe Community Professional

          The PAR is correct as you're seeing it in Pr.  Starting in CS4, Adobe updated the PAR values of all their video apps to match the BBC standard.  The thin black bars you are seeing are aesthetically objectionable, but technically accurate.

           

          However, even on a widescreen HDTV, the set's overscan will hide the black bars and your audience will never see them.

           

          -Jeff

          • 2. Re: Scaling 720p to NTSC DVD Widescreen
            MarkCohenDev Level 1

            Thanks for the response, Jeff.

             

            One problem is that most, but not all, of our users will be viewing these DVD's on computers, which won't have the overscan problem.  But that's not the biggest problem.

             

            When this video is rendered as an MPEG-2 video, Premiere sets the DAR flag in the MPEG2 elementary stream header to 16:9, like it should.  Since the video frame is 720x480, the video player correctly reads that DAR from the header and scales the frame from 720x480 to 853/480 (16:9).  The problem is that now the aspect ratio of my original 720p video is incorrect since Premiere, when compositing, thinks it's cute to scale the video for a 704x480 frame instead of a 720x480 frame because it assumes a 1.21r PAR on a 720x480 frame (which scales to 872/480; which is, of course, no longer a 16:9 DAR).  Thus, our video ends up being incorrectly scaled.  This is a deal-breaker for us.  Seems the only solution is to crop our video vertically so that it would scale correctly from a 704x480 frame even though it's being placed in a 720x480 frame.  So then our originally video will end up being cropped vertically and then cropped both horizontally and vertically on overscan displays, but at least it would retain the original display aspect ratio of the 720p footage.

             

            I suppose I'd have better luck melting a glacier with my breath than having my way.  I guess I'll compose in Premiere at 1280x720 and encode with a tool that lets me decide how to scale the video.

            • 3. Re: Scaling 720p to NTSC DVD Widescreen
              Colin Brougham Level 6

              You're making it way more difficult that you need to: simply crop 8 pixels off the top and bottom of the frame during export, and it will scale correctly to a 720x480, widescreen DVD.

               

              Crop settings:

              crop_setting.jpg

              Without crop, output looks like this:

              output_without_crop.jpg

              When you crop 8 off the top and bottom, output looks like this:

              output_with_crop.jpg

              • 4. Re: Scaling 720p to NTSC DVD Widescreen
                Jeff Bellune Adobe Community Professional

                What Colin said.

                 

                -Jeff