7 Replies Latest reply on Oct 4, 2016 5:06 AM by Rick Gerard

    Timewarp breaks frames

    MichaelV.

      Hello everyone,

       

      I'm having a problem with timewarps ... whenever I use the effect the videoframe gets "broken" as seen here. The keyframes are simple from 100 speed to 0. If I change it from 100 to 50 the one "broken" videoframe is gone, but occures at another frame looking differently. My effect settings are the standard ones - meaning I only changed the "speed".

       

      Footage is a .mov file

      I'm using After Effects 2015 - Version 13.6.0.165

       

      My system:

      Xeon E5-1650 v3 @3.5 GhZ

      AMD FirePro W5100

      32 GB RAM

      Windows 10 64-bit

       

      Anyone else having this problem and a solution/workaround (maybe Premiere)?

       

      Sorry for my English - it's not my native language.

       

      Thank you and best wishes

        • 1. Re: Timewarp breaks frames
          Mylenium Most Valuable Participant

          Well, have you actually checked your framerates? This usually happens when your comp framerate and footage interpretation are out of alignment and naturally then the math in the effect gives wrong results.

           

          Mylenium

          • 2. Re: Timewarp breaks frames
            MichaelV. Level 1

            I have everything on 25 FPS ...

             

            Edit:

            I even get it if I add it to the footage without changing the effect at all. The footage by itself is totally fine and any other animation except to time works :S

            When I set it back to 100 all is fine again Even only a speed of 99 totally breaks the footage - some frames are total blackscreened.

             

            Unbenannt.PNG

            • 3. Re: Timewarp breaks frames
              Mylenium Most Valuable Participant

              You are working in 32bit, which doesn't exactly make sense. Switch to 8bpc or 16bpc.

               

              Mylenium

              • 4. Re: Timewarp breaks frames
                Dave LaRonde Level 6

                I don't trust footage like mp4/mpeg/h.264 to work properly when playing around with time, due to the way the footage is compressed.  I recommend transcoding a test clip to a different media container & codec.  I like transcoding to quicktime movies in Photo JPEG, JPEG 2000, Animation, PNG or ProRes codecs.

                • 5. Re: Timewarp breaks frames
                  MichaelV. Level 1

                  Tried Dave's solution: JPG worked the best where at one point I only had 1 black frame, but I can never get all frames working properly. The broken footage even occurs if I only slow down from 100 to 70, so I think it really does not matter how strong the timewarp is.

                   

                  I even get it when I use a picture without any motion and use the timewarp effect on it ...

                   

                  Unbenannt.PNG

                   

                  There are even weird frames like this one:

                  Unbenannt.PNG

                  Where the footage even changes its position

                  • 6. Re: Timewarp breaks frames
                    MichaelV. Level 1

                    After updating to the latest version it seemed to be fixed ... but in the end nothing changed.

                     

                    No one ever had this problem on the adobe forum?

                     

                    • 7. Re: Timewarp breaks frames
                      Rick Gerard Adobe Community Professional & MVP

                      I've never seen this problem using image sequences or frame based production codecs. I have seen weird things happening when you try and time remap video that has inter-frame compression.(MPEG for example) Inter-frame compression looks at many frames and makes a single frame that has most of the image data for that frame. It relies on the CPU to guess where the pixels are moving in the other frames and as long as you don't monkey with the playback speed it usually does a pretty good job of guessing where the pixels should be. When you change the speed slightly using time remapping things can easily get fouled up.

                       

                      The solution is to transcode your footage to a suitable frame based format or image sequence so that the only calculations that are made when changing speed are based on the differences in the position of the detail between one frame and the next. I never try and time remap AVCHD or MP4 footage without first converting it to an image sequence or a frame based intra-frame codec.

                       

                      Check out this article for a better understanding of how compression works. Intra-frame vs Inter-frame Compression | Wolfcrow