3 Replies Latest reply on Aug 15, 2011 10:24 AM by Colin Brougham

    Mixed DV & HDV "Scale to Framesize" Not Working Well

    remy4444

      I'm running CS 5 and I have a project with two media types:

      DV - 720 x 480 (1.2121) as a .avi

      HDV - 1440 x 1080 (1.333) as a .mpeg

       

      I've tried two different project settings - one as DV 720 x 480 and another as HDV 1080.  After adding both media files to the timeline I select whichever clip doesn't fit the frame and select "Scale to Framesize".  It gets the picture size CLOSE, but there's still about a 2-3 percent gap on two sides (depending on which frame setup, either the top and bottom or left and right) of the frame.  I exported the video just to make sure, and sure enough the output includes the variance of the slightly mis-matched frame.

       

      I've tried interpretting the footage of one file to match the aspect ratio of the other and that just makes it worse.  Any ideas?

        • 1. Re: Mixed DV & HDV "Scale to Framesize" Not Working Well
          Colin Brougham Level 6

          DV Widescreen and HDV/HD have slightly different display aspect ratios (DAR), due to the way that pixel aspect ratio (PAR) is calculated and expressed in Premiere Pro. As a result, DV Widescreen's aspect ratio is slightly wider/shorter than HD's aspect ratio.

           

          When you drop an HD clip into the DV Widescreen sequence with Scale To Frame Size set, it will decrease until it fits the entire image within the frame; this is why you see the black bars on the sides.

           

          Though not quite as automatic as Scale to Frame Size--and especially if you plan to export to a DV sized output, like DVD--you can manually scale the HDV clips down to fully fill the DV Widescreen frame, essentially eliminating the black bars, by using the Motion > Scale parameter. It should be right around 45.5%; you'll crop a little off the top and bottom of the HDV, but it's pretty minimal. Save an effect preset for that Motion > Scale tweak, and you can easily apply it to other HDV clips; I've got a few of them created for using different sized assets in non-matching sequences.

          • 2. Re: Mixed DV & HDV "Scale to Framesize" Not Working Well
            remy4444 Level 1

            Awesome!  That worked out just fine.

             

            Many thanks!

            • 3. Re: Mixed DV & HDV "Scale to Framesize" Not Working Well
              Colin Brougham Level 6

              Glad to help!

               

              If you're really curious about what's going on under the hood (fair warning: it's all mathy and stuff), check out this blog post from Todd Kopriva with links to a number of articles: pixel aspect ratios in After Effects CS4 and other applications in Creative Suite 4 Production Premium « After Effects region of interest. Despite being on an After Effects blog, and from the CS4 version, the information is relevant to Premiere Pro CS5/CS5.5, as well.

               

              Also, I'd be remiss if I didn't note that, should you ever be working in an HD/HDV sequence and wishing to export to something like a widescreen DVD, you'll encounter this issue again. Fortunately, there are cropping capabilities within the Export Settings window that let you account for this. Cropping a few pixels off the top and bottom of your image will allow the frame to be fully filled and eliminate the black bars.