5 Replies Latest reply on May 26, 2013 8:32 AM by Steven L. Gotz

    I need to skip half the frames... suggestions?

    SLTyPete Level 1

      I'm capturing film-to-video using a new device. It grabs two video frames for each film-frame.

       

      The nice thing about this: I can use temporal filtering of the frame pairs to eliminate much of the noise in the source capture.

       

      The painful thing about this: typically, the first of each frame pair is defective around the edges (due to the way the shutter works) and I **really** want to drop half the frames.

       

      It just doesn't look good when I leave the frames in place.

       

      Thus, my question. Is there a method or plugin or ??? that can skip half the frames in a clip? Or, how hard would it be to write such a plugin?

       

      Your thoughts mucho appreciated.

       

      Pete

        • 1. Re: I need to skip half the frames... suggestions?
          SteveHoeg Adobe Employee

          Create a sequence at exactly half the frame rate of your footage and place your clip in that. Using that sequence in place of your footage will skip alternating frames.

          • 2. Re: I need to skip half the frames... suggestions?
            Dave Merchant MVP & Adobe Community Professional

            Setting the clip to 200% speed will automatically drop half the frames, but it's hard to control which. You'd also need to disable frame blending on export.

             

            In After Effects it's easy as you have frame-by-frame trimming controls - again you would start by doubling the clip speed, but if necessary you can zoom right in and delete frame 1 to swap which frames are retained. There's no unwanted frame-blending in AE.

            • 3. Re: I need to skip half the frames... suggestions?
              Steven L. Gotz Level 5

              Dave's answer made me curious. Sorry Dave, but that isn't accurate.  Steve's answer in post #1 works, but when I tried it, it started with a 1 and then shifted to a 2. I am not sure why.

               

              I just tested using the 200% setting to eliminate every other frame, and then setting the result to 50% to regain the original speed of the video and it worked perfectly. Premiere Pro was dead on. This may require progressive instead of interlaced footage (I didn't check), but Pete's is likely progressive.

               

              The following screen capture explains my test.

               

              • 4. Re: I need to skip half the frames... suggestions?
                SLTyPete Level 1

                Hi all,

                My sincere apologies for disappearing... some Real Life (medical issues) intervened for a few months.

                 

                The double/half solution works perfectly. Not only that, but it seems robust enough to use in a variety of ways.

                 

                For example, if I modify the interpretation of the clip (rather than do all this through sequences), I can tell Premiere Pro to imagine that my clip is a 59.94 clip instead of 29.97... and I *think* (not tested yet) can even tell it that it's interlaced and change between upper/lower-first fields to decide which one is retained or dropped.

                 

                In any case, this works perfectly.

                 

                The original data isn't really I or P... it is captured film with two captures of each film frame. One while the film is moving, one while it is not in motion. Of course I need the non-moving frames.

                 

                THANK YOU THANK YOU!!!!

                 

                Blessings,

                Pete

                • 5. Re: I need to skip half the frames... suggestions?
                  Steven L. Gotz Level 5

                  Glad you are doing better, and glad we could help.