MP4 files that skip?

Discussion in 'Apple TV and Home Theater' started by JMEANS, Jun 3, 2013.

  1. macrumors regular

    Joined:
    Jun 9, 2012
    #1
    So I have a few MP4 that for whatever reason when imported into iTunes skip or better description would be stutter along when playing in iTunes and are basically unwatchable : (

    The quality of the file is great just doesn't play properly, any known culprit you can think of that would cause suck an issue?

    After dropping into 'file info' software the audio looks normal but the video info reads AVC even though the file has the .mp4 extension, that right? Thanks Jim
     
  2. Moderator

    SandboxGeneral

    Staff Member

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    Sep 8, 2010
    Location:
    Detroit, Michigan
    #2
    I assume that the files play just fine in another player before going into iTunes right?

    Any change of ripping them again and directly into iTunes?
     
  3. thread starter macrumors regular

    Joined:
    Jun 9, 2012
    #3
    Yes perfectly fine in VLC. ITunes certainly imports them due to the mp4 container, but somewhere along the line within the file there is a factor that doesn't contain complete mp4/ iTunes compatibility.... Weird

    On another note what is AVC video file?
     
  4. Moderator

    SandboxGeneral

    Staff Member

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    #4
    H.264/MPEG-4 AVC
     
  5. thread starter macrumors regular

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    Jun 9, 2012
    #5
    Thanks pretty much what I thought with AVC, however with the file stutter, my best guess is an audio thing, I will run it thru Mp4Tools and add a 2 channel track?
     
  6. macrumors 65816

    Joined:
    Sep 16, 2007
    #6
    Try play it QuickTime X. The iTunes player has always been horrible for me.
     
  7. macrumors 603

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    Jun 7, 2011
    #7
    Can you upload the shortest of them somewhere (e.g., copy.com - it has 20 GB free) so that we take a look?
     
  8. thread starter macrumors regular

    Joined:
    Jun 9, 2012
    #8
    Thanks for asking, but all i can do is send along this direct info from the file. This is after i ran the .avi file thru MP4Tools adding a 2 channel audio and changing the container to .mv4

    Again it plays fine in VLC and can import to iTunes, however when it plays in iTunes it stutters a long...

    I have changed containers with many files I haven't Handbreaked myself and have had success, however some are picky like this one. Thanks again for any help you can send my way - Jim


    [​IMG]
     
  9. Idgit, Jun 6, 2013
    Last edited: Jun 6, 2013

    macrumors 6502

    Joined:
    Mar 14, 2004
    #9
    Your MP4 does not contain a h.264 video file. It looks like it's an Xvid-encoded Mpeg-4 file. I suspect that is the source of your problem. Transcode it with Handbrake (with audio passthrough).
     
  10. macrumors 603

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    Jun 7, 2011
    #10
    Yup, it's Xvid, this is why there are problems.
     
  11. thread starter macrumors regular

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    Jun 9, 2012
    #11
    thanks everyone

    but crap : ( really didnt want to handbreak (transcode) a movie that has all ready been transcoded, quality will be reduced i suspect.
     
  12. macrumors 6502

    Joined:
    Mar 14, 2004
    #12
    It's already a high bitrate file, so I wouldn't worry about quality loss. Set Handbrake to RF18 and the difference will be negligible.

    Or, given that your file is a Scene torrent, download a proper h.264/x264 BluRay rip.

     
  13. dynaflash, Jun 6, 2013
    Last edited: Jun 6, 2013

    macrumors 68020

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    Mar 27, 2003
    #13
    Yes, it will. but depending on what settings you use ... it is possible to reduce quality but have it all but visually undetectable depending on your source and settings. While I don't want to get into the semantics of what you can or cannot see ... it is possible *usually* (there again depending on source) to get a decent transcode to where you basically can not tell the difference with the naked eye.

    However it looks like you have an xvid (divx) video track ... that does not bode well as they kind of suck to begin with ... pardon the expression.

    While its outside the scope of this post ... video transcoding is a bit of a shell game when it comes to quality loss ... you can lose quality in places where the human eye has a hard time detecting it. If done properly ... you will never notice .. and frankly who cares about quality loss that you can't detect ? I know I don't. It may show up in some ssim or psnr number from the encoder but frankly typically that does not please the human eye.
     
  14. thread starter macrumors regular

    Joined:
    Jun 9, 2012
    #14
    thanks guys, very familiar with HB and the ins and outs, i usually rip my own collection of blu's etc but i am finding HD versions of films like GHOSTBUSTERS 2 and JAWS 2 etc that have not yet been released on Blu, so i go looking on PB for HDTV captures such as this file to get an HD copy.

    I will try HB and see if i notice a significant change and honestly I usually dont, my concern mainly was not wanting to reduce the file size any.

    thanks again
     
  15. macrumors 68020

    Joined:
    Mar 15, 2012
    #15
    I think you may have opened a can of worms with that statement, Dynaflash! :eek:

    But I totally agree and wish we would get past this "anything that is not a bit-for-bit copy is unacceptable to watch". That approach causes a lot of people to spend a lot more time and money getting their movies on their media players than is necessary.
     
  16. macrumors 68020

    Joined:
    Mar 27, 2003
    #16
    I thought the same thing right after I posted it. oh well in this case with an xvid video track there isn't much choice as remuxing is not an option if I understand the situation correctly.
     

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