5 Replies Latest reply on Nov 13, 2012 9:51 AM by 3-1415

    Video/Audio speed unsynced


      The audio seems to play at a slightly higher speed than the video in Ae.

      You don't notice it in the beginning, but after just under 40 min it reaches a few seconds. It's not relative to where you begin the preview, but to the work area.

      No difference between auido and RAM preview.

      Some of the material is in the ever-dreaded .mp4 format, but the problem occus for .avi aswell.

      The problem is not composition-specific, as a separate composition, with only one 40-minute long avi layer, has the exact same problem.

      I have not been able to determine wether it's the auido that's too fast or the video that's slow. It appeared quite recently, so it's not something with the files themselves.


      Ae CS6.11.0.0378, I think

      Demo version

      7,9 g ram allocatable

      Win7 proffesional

      Only .avi and .mp4, can't tell much more than that


      And don't tell me to extract the audio and add it separately. I wan't to solve the problem, not circumvent it.


      Also, don't be suprised if i've just missed some obvious part of how it's supposed to work. I'm still quite new to this.

        • 1. Re: Video/Audio speed unsynced
          Mylenium Most Valuable Participant

          What is your footage interpretation? What your audio sample rates and timebase? That aside, "circumventing" it by separating audio and video is a valid solution even if it may be inconvenient.



          1 person found this helpful
          • 2. Re: Video/Audio speed unsynced
            3-1415 Level 1

            Interpretationconf.pngCouldn't find the interpretation config file, this screenshot is all I can come up with.

            The sampling rate was set to default, 2048. However, when I increased it to maximum,  8192, the video delay became slightly smaller, but it was still there. Is there anyway to get it even higher?

            I don't really know much about the timebase. Wish I could tell you more.

            • 3. Re: Video/Audio speed unsynced
              Dave LaRonde Level 6

              There's one thing I see that's certainly wrong: the frame rate.  It shouldn't be 23.970, it should be 23.976, and yes, that tiny-little variation makes a difference.


              I'd like to know how you're RAM Previewing a clip that's 40 FLIPPIN' MINUTES LONG with just 8 gigs on your machine.  People with 64 gigs of memory can't prevew for that length of time, so how are you doing it?


              Something just doesn't add up here.  You can start by describing in detail how you do your RAM Previews.

              • 4. Re: Video/Audio speed unsynced
                Mylenium Most Valuable Participant

                Agree with Dave. Ever since fixing a few things in CS4 in terms of framerates and pixel aspect ratios, The Adobe video tools are über-exact and require the proper values. That 6 microseconds sounds like about right making your audio drift noticeably after a while...



                • 5. Re: Video/Audio speed unsynced
                  3-1415 Level 1

                  Thanks, dave. Correcting it screwed up my frame-frozen layers a bit, and crashed my after effects a couple of times (with an 17:18 error message that reappeared as soon as I removed it) before I got around to convert some of the mp4:s to avi, but in the end it seems to have worked.


                  " yes, that tiny-little variation makes a difference."

                  I'm not at all suprised. In fact, I suspected that it was a centimal or so that was the problem.



                  "I'd like to know how you're RAM Previewing a clip that's "40 FLIPPIN' MINUTES LONG"

                  It's really quite short.(Edit: 00:03:16:??) It's just that I accidentally placed it near the end of a 40-minute work area, and haven't found ot how to move the entire composition. Sorry if I confused you.