converted .AVI audio out of sync

Discussion in 'Apple TV and Home Theater' started by From A Buick 8, Dec 9, 2012.

  1. macrumors 68030

    From A Buick 8

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    #1
    Hello, I am having an issue with .AVI files that I am converting for iTunes. The audio is out of sync. I am converting using HB. The AVI files play fine (audio in sync), but after the conversion playing them on the apple tv the audio is not in sync.

    I can play the .AVI file on the ATV ( using air video) and the audio is in sync, so it must be a setting I am missing during the HB conversion. I really want these in iTunes for easy playback.

    I doubt it matters but these are old VHS tapes that were converted to .AVI files.
     
  2. macrumors 6502

    Joined:
    Mar 14, 2004
    #2
    Open the file up in Media Info and look to see if it has a packed bitstream. If it does, unpack it with Batch Unpacker and convert the unpacked AVI using Handbrake.

    If that doesn't work, try converting it with Quicktime Player or MPEG Streamclip (which uses Quicktime). Just use one of the presets, like the Apple TV 2 one. For some reason, Quicktime can sometimes successfully convert problematic AVIs where Handbrake and other ffmpeg-based converters can't.

    I have also had some AVIs that just could not be converted without audio sync problems. There was just something funky about them.
     
  3. thread starter macrumors 68030

    From A Buick 8

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    #3
    thanks i will try this, these are old episodes of MST3K, my son has recently found the joy of that program and we have seen all that netflix has to offer.
     
  4. thread starter macrumors 68030

    From A Buick 8

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    #4
    Not sure if the bitstream is packed or not, here is what i see when I open it in media info. Also when i play the file in iTunes on my iMac the audio sync issue is not there, it only shows up when streaming on the ATV
     

    Attached Files:

  5. macrumors 6502

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    #5
    Whatever app you're using, doesn't seem to display enough information. Try VideoSpec [free] or the open source MediaInfo.

     
  6. thread starter macrumors 68030

    From A Buick 8

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    #6
    I had used media info, here is what i see with video spec
     

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  7. macrumors 6502

    Joined:
    Mar 14, 2004
    #7
    Thanks for that screenshot. The big thing that stands out to me is that your AVI doesn't contain a XVID or DivX video file, but rather a MS MPEG-4 v2 video file. That is most likely the source of your sync problems.

    The audio is also in mono, not stereo. So I'm not surprised that you had sync problems.

    My first suggestion would be to look for better quality files. Yours is low-res, mono, and encoded with a old, non-standard codec. You might want to try your public library. I've gotten many TV DVDs for old shows from our library system and ripped them.

    However, if you still want to convert that file, make sure you have the latest Perian codec installed and try converting the video file with Quicktime. You might have to tinker with the settings. Keep the audio to mono. If you're lucky, it'll work.
     
  8. thread starter macrumors 68030

    From A Buick 8

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    #8
    Thanks for the help i will give that a shot.

    ----------

    Is it weird that the converted files does not have the sync problem when played through itunes on my mac, and only shows up when streamed through the ATV
     
  9. macrumors 6502

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    Mar 14, 2004
    #9
    That's interesting. In the converted file, what HB preset did you use? Is the audio track AAC stereo or AAC mono?
     
  10. thread starter macrumors 68030

    From A Buick 8

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    #10
    Here is a screen shot of the same file as a .m4v
     

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  11. macrumors 6502

    Joined:
    Mar 14, 2004
    #11
    The only thing that stands out is the High@2.1 profile. Is that from the Apple TV 3 preset? Might want to try a Main profile encode.

    I would try a re-encode using the iPad or Apple TV 2 preset in Quicktime to see if it works. If it does, the problem is with Handbrake and certain files.
     
  12. thread starter macrumors 68030

    From A Buick 8

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    #12
    All I have, is the Quicktime player I was thinking about getting quicktime though. Looking at the Mac App Store i do not see it
     
  13. macrumors 6502

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    Mar 14, 2004
    #13
    You use Quicktime Player to export the video file to another format. But you can use MPEG Streamclip, which is an excellent free app.
     

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