AC3 & DTS Passthru broken in iTunes 10.4 (Cocoa 64 bits)!

Discussion in 'Apple TV and Home Theater' started by uvitor, Jul 22, 2011.

  1. uvitor macrumors member

    Joined:
    Sep 1, 2010
    Location:
    Brazil
    #1
    Hi fellows,
    the title says all: when i installed iTunes 10.4 in my Mac Pro (mid 2010, Hex) my movies stopped to play the surround track. QuickTime 7 Pro and other players play fine.
    Is that just me or others are having the same issue?
    Thank you for your time.
    PS: the MAC OSX is Lion
     
  2. uvitor thread starter macrumors member

    Joined:
    Sep 1, 2010
    Location:
    Brazil
    #2
    Anyone?
    I reverted to 10.3.1 and everything is fine including ac3 and DTS passthru. 5.1 working as it should be.
    So, because anybody answered the first post, i suppose it's just me having this particular issue, isn't it?
     
  3. EmpyreanUK macrumors regular

    Joined:
    Mar 6, 2011
    #3
    As far as I know iTunes cannot play AC3 audio without the Perian plugin —*perhaps you already have this installed, but it hasn't been updated for iTunes 10.4? That's the only explanation I can think of for why it worked when you rolled back to 10.3.
     
  4. Alrescha macrumors 68020

    Joined:
    Jan 1, 2008
    #4
    I can't reproduce the problem. Both iTunes movies (Terminator 2) and my own Handbrake-created files work fine. I am using an M-Audio Transit as my output device.


    This hasn't been the case for some time. iTunes supports multiple audio tracks and allows you to choose between then using the on-screen GUI during playback. To be fair, it has not always worked 'like magic'.

    A.
     
  5. AdrianK macrumors 68020

    Joined:
    Feb 19, 2011
    #5
    Yeah, but it doesn't ship with a decoder, I think this is what EmpyreanUK was referring too (though I understand that you're after passthrough). Anyway, it a moot point.
     
  6. shorn macrumors regular

    Joined:
    Jun 29, 2010
    #6
    I'm having a similar issue which I posted about recently, but got no reply.
    Before 10.4 I could play (mainly my own 720p/ac35.1/aac2.0) rips, and they would play fine, and I could choose either audio track.

    Now, the surround channel is greyed out, and the movie plays but I get no sound from the aac 2.0 audio either! Very strange.

    All files play fine in VLC and play perfectly in AppleTV (2).
     
  7. uvitor thread starter macrumors member

    Joined:
    Sep 1, 2010
    Location:
    Brazil
    #7
    So, are you guys doing the terminal hack to pass thru AC3/DTS to receiver?
    I'm doing exactly that.
    Maybe is indeed a perian fault, maybe not. The fact is: i'm (was) a huge fan of iTunes simplicity and was totally dedicated to convert all my movies (750 mkv bluray rips) to .mov or .m4v being complient with iTunes/Quicktime universe.
    Now, i am obligated to use Plex that doesn't read mov's subtitles!! What a stupid upgrade apple did that from day to night ******* all my movies (when a i say "all" i mean exactly ALL).
    PS: Incredibly they play well using Quicktime 7 pro. I sincerely don't understand that.
    PS 2: I used mostly iFlicks and quicktime pro to convert the movies.

    Please some advice is welcome.
    Thanks for your time guys.
     
  8. Alrescha macrumors 68020

    Joined:
    Jan 1, 2008
    #8
    No. I'm not using any hack, nor is Perian installed. For several releases now iTunes has supported AC3 passthru. The latest release works fine for me with both iTunes store content as well as my Handbrake converted files.

    A.
     
  9. uvitor thread starter macrumors member

    Joined:
    Sep 1, 2010
    Location:
    Brazil
    #9
    Could you give me your Midi setup and sound settings?
    Is it because you have a different device as output?
    Because when i undo the hack even in iTunes 10.3 the movies lack support for AC3 pass thru.
    The instructions to pass thru that i use are:
    http://www.cod3r.com/2008/02/the-correct-way-to-enable-ac3-passthrough-with-quicktime/

    Thanks.
     
  10. Alrescha macrumors 68020

    Joined:
    Jan 1, 2008
    #10
    Your instructions are three years old, a lot changes in that amount of time.

    It works the same whether I use the internal sound or the M-Audio Transit. I use the Transit only because in the past OS X did not always share the digital output well between applications, so I decided to use a dedicated device for AC3 passthru.

    My Sound and Audio Midi settings are OS X default. I do not touch them. The only thing I do is choose the audio track in iTunes. Here are pics of the settings when I am playing a movie with DD5.1 using the internal optical port:
     

    Attached Files:

  11. uvitor, Aug 21, 2011
    Last edited: Aug 21, 2011

    uvitor thread starter macrumors member

    Joined:
    Sep 1, 2010
    Location:
    Brazil
    #11
    Ok, i did exactly that and worked like a charm for my recent encoded movies in m4v format with 2 audio tracks (stereo and ac3 surround). But the majority of my previous encoded movies are .mov with just the ac3 track and they don't play without perian because iTunes don't pass thru those files (i don't know why). When i install perian, the movies that was playing nice doesn't play anymore. So, now i don't know if it worth to get rid of perian and remux all my movies again to play fine.
    Thanks in advance for your help.
     
  12. Alrescha macrumors 68020

    Joined:
    Jan 1, 2008
    #12
    I can speculate that the only format iTunes is likely to <ever> support is the one used by the iTunes Store, i.e. an m4v file with an AAC track followed by an AC3 track. Indeed, testing my old 5.1 mov files from the days before Handbrake shows that iTunes won't even play most of those.

    A.
     

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