8 Replies Latest reply on Sep 6, 2016 6:11 PM by Arivl

    "Interpret Compositon" Script

    Arivl Level 1

      When working with vendors supplying things like matchmove or 3D, I often get projects back in the wrong framerate.  Basically, imagine I have a comp which is 100 frames long at 24fps and has tracking data for each frame.  Sometimes the comps I get back are, for example, at 30fps.  It's still 100 frames long, and all the data lines up per frame, but it's all at the wrong framerate, so the shot in this case would be playing faster than normal.

       

      At this point, I've got two options: 

       

      •I can go back to the vendor and say "Hey!  Fix this!" which will take 24hrs at least, and may still not be right.  Or:

      •I can copy the keyframe data into a text editor and change the framerate header to the proper frame rate, and paste it back in.  This works pretty well, except if there are many many layers in the project.

       

      If the composition was a footage layer, the "Interpret Footage" dialogue would solve the problem.  However, no such option exists for compositions.  Merely changing the composition's framerate would leave me with extra frames and data that doesn't line up.

       

      •The RD_Compsetter script is very useful for related tasks, but unfortunately just changes the comp framerate as you would in Compositor settings.

       

      What I'm wondering is this:  Is there a way (probably a script) to "Interpret" the composition and all keyframe data in it as a different framerate?

        • 1. Re: "Interpret Compositon" Script
          Mylenium Most Valuable Participant

          It would not be too difficult to modify some existing script or create a new one that copies the keyxframes from a source comp to a new comp, but I'm not aware of an existing (free) script. Perhaps there's such a function e.g. in Mathias Möhls various tracker-related commercial scripts...

           

          Mylenium

          • 2. Re: "Interpret Compositon" Script
            Roei Tzoref Adobe Community Professional
            Merely changing the composition's framerate would leave me with extra frames and data that doesn't line up.

            how about pre-comping the composition, in the master comp set the desired frame rate, and in the nested comp choose "preserve frame rate when nested" ?

            • 3. Re: "Interpret Compositon" Script
              Dave LaRonde Level 6

              I'd simply render out the problem comps as image sequences, import them into AE, and conform the frame rates in the interpret footage settings.

               

              Or specify the required frame rates in no uncertain terms, which seems to be the root of the problem.  Do that, and the problem goes away.

              1 person found this helpful
              • 4. Re: "Interpret Compositon" Script
                Rick Gerard Adobe Community Professional & MVP

                Arivl wrote:

                 

                At this point, I've got two options:

                 

                •I can go back to the vendor and say "Hey! Fix this!" which will take 24hrs at least, and may still not be right. Or:

                •I can copy the keyframe data into a text editor and change the framerate header to the proper frame rate, and paste it back in. This works pretty well, except if there are many many layers in the project.

                You are not understanding tracking info or frame rates or how keyframes work. Changing the frame rate in the text editor will not work.

                 

                If your comp and your footage are both interpreted as 30 fps then go into the footage and change the interpretation to 24 and go into the comp change the frame rate to 24. If the timeline is set to timecode everything should line up just fine.

                 

                It that a does not fix your tracking alignment problem then I'm not understanding the workflow.

                • 5. Re: "Interpret Compositon" Script
                  Arivl Level 1

                  Dave, this is basically the solution(s) I've landed on.  It's just a problem I've run into more than once and was hoping for a "streamlined" solution.

                   

                  But yes, both answers are valid solutions, and I've more or less resigned myself to those approaches.

                  • 6. Re: "Interpret Compositon" Script
                    Arivl Level 1

                    Rick, your advice is always most helpful, but in this case I can assure you that I do understand how tracking info, frame rates, and keyframes work.   While I'm sure I'm not nearly as expert as you, I have been working full-time in AE for the last 15 years, and taught a few classes in it, so I think I've got the basics down.

                     

                    As a matter of fact, I have tried changing the frame rate in the text editor, and I can tell you with certainty that it does work.   For shots where all I need to convert is the camera, I've used that approach, and it works flawlessly.  Were I willing to do that one layer at a time, that would be a solution.

                     

                    Unfortunately your proposed solution — while totally valid— is for a different situation, and as I mentioned, would leave the keyframes misaligned to the actual frame numbers in the composition.

                    • 7. Re: "Interpret Compositon" Script
                      Rick Gerard Adobe Community Professional & MVP

                      I've never had a problem with keyframes that were not aligned to the start of a frame. Like I said, I'm not exactly sure what you are working with.

                      • 8. Re: "Interpret Compositon" Script
                        Arivl Level 1

                        Sorry, seems I could've described my problem more clearly.  In this case I am not having a problem with keyframes being aligned to the start of a frame.

                         

                        In this case, all the keyframe data lines up per frame, but it's all at the wrong framerate, so the shot in this case would be playing faster than normal.

                         

                        So the footage sequence is interpreted at, let's say, 30fps, as is all the keyframe data fro the camera, and dozens of nulls.


                        Frame 1 contains the first frame of picture, as well as the first frame of keyframe data for the camera, and all the nulls.

                        Frame 100 contains the 100th frame of picture, as well as the 100th frame of keyframe data for the camera and all the nulls.

                         

                        The only thing wrong, from a practical standpoint is that the comp is at 30fps instead of 23.976.

                         

                        I could change the comp framerate, except that were I to do so, the 100th frame would no longer contain the 100th frame of keyframe data.   Does that explain the issue more clearly?