External audio clip runs slower than video

Discussion in 'Digital Video' started by avalon4053, Dec 28, 2009.

  1. avalon4053 macrumors newbie

    Dec 28, 2009
    Hello, I have a situation where I have a concert video clip and external audio clip that runs slightly slower than the video. I want to mix the audiotrack of the video and the audiotrack of the external audio clip (like 60% volume audiotrack1 and 40% volume audiotrack2) and of course now I have a problem. After about 2 minutes, they go so much out of sync that you can't use it.

    Currently I only have iMovie 09 - any way of getting this done in iMovie? If not, where else?

    Best from Switzerland, avalon
  2. spinnerlys Guest


    Sep 7, 2008
    forlod bygningen
    It looks like the video (shot on DV or what?) and the audio (recorded where?) have different sample rates.

    Can you identify the sample rates of both video and audio?
  3. xStep macrumors 68000

    Jan 28, 2003
    Less lost in L.A.
    I think spinnerlys is on to the problem.

    The easiest way to convert the external audio file might be to import it into iTunes, change the default import encoding of iTunes to an appropriate codec, sample size and sample rate, then tell iTunes to convert the file via a right click.

    I'd probably just use QuickTime 7 to inspect each files specs.
  4. treehorn macrumors 6502


    Aug 21, 2007
    I've had this problem many times thanks to having crappy soundfeeds that need to be augmented by CDs and while changing the audio (which I'm guessing is in 44.1khz - CD Quality, instead of 48ghz - DAT/Video Quality) will probably help, I'd be prepared if I were you to having to do a lot of massaging - cutting the audio every couple of minutes to slip it a couple of frames to keep it on track.

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