1 Reply Latest reply on Jul 22, 2011 8:49 AM by Mylenium

    Mismatch between preview and output




      I'm new to After Effects, and having some problems with a project I'm working on..


      It's a fairly simple project, just some tracking and replacing elements in a video clip.

      Everything looks fine in the RAM preview, things line up and the timing looks good.


      However, I run into problems when I want to render the final result.

      Everything seems to be off, with regards to the timing. It looks like all my keyframes

      are off by a few frames, leading to misalignment.


      As I said, I'm new to After Effects (this is my first attempt at editing any kind of video),

      and I suspect I screwed up right at the begining of my project.

      The original footage is 23,970 fps, but I changed the composition framerate to 23,976 fps.

      Can't remember why exactly, I suspect it had something to do with tracking in Mocha..

      Could this be the reason my output is off?


      Any tips on how to correct this, without trying to figure out how many frames each pre-comp

      is off, and manually correcting them? I have about 20 elements which would need editing..


      Any help is much appreciated!

        • 1. Re: Mismatch between preview and output
          Mylenium Most Valuable Participant

          If you cahnged the comp framerate, anturalyl you would also have to forcibly override the source footage framerate in the footage interpretation. Other than that you could be seing issues with interlaced footage where in the "inbetween" areas, that is the alternate field, your motion is interpolated linearly from the preceding even field to the next one on a whole frame basis, making it look misaligned because it is in teh wrong position, naturalyl. Check that, too. If all fails, force conform your footage to a "clean" framerate e.g. by time-stretching it and rendering a suitable clip for mocha. You can always go back to the original then or time-stretch back later or scale the keyframes temporally. Many ways to skin the cat....