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My AC3 Codec is not working. Help!

58746 Views 70 Replies Latest reply: Jan 3, 2014 6:40 AM by tmkee RSS
  • Bartbrn Level 1 Level 1 (10 points)
    Currently Being Moderated
    Jan 30, 2013 7:36 AM (in response to CheeMiss8)

    Got it, thanks!

     

    Don't give up on DivX -- it's just a matter of getting the right codecs (like the updated a52AC3 and Perian) and don't automatically believe, as the a52 codec page tells you, that you have to ditch Quicktime's DivX codecs. In MY case, I needed them, which I found out by moving the QT DivX codecs to a folder on an external drive, restarting, and then trying to get DivX to work. DivX would NOT work for me without the Quicktime DivX codecs back in their correct folders.

     

    f you use Firefox for a browser, go to Tools > Add-Ons > Extensions, and disable the DivX Plus Web Player HTML5 add-on. Safari and Chrome should work without fiddling about with THEIR extensions or add-ons at all.

     

    Good luck, and thanks again!

     

    Bart

  • Manfred34 Level 1 Level 1 (0 points)
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    Mar 23, 2013 1:09 PM (in response to jpdemers)

    Since the original link no longer carried the file, the one that jpdemers posted is the one that works....  Thank you!!  I had the same issue with no audio from files using AC3 using either, QT 7 or 10, or Divx...had already installed Perian some time ago, but did not have the A52 codec.  I followed jpdemers instructions and the only hiccup is that when you try to set Perian to Multi-Channel Output, it gives you an error message and directs you to the instructions(and also kind of insults your intelligence to some degree) and tells you that's not how you do it, but after i ignored all of that stuff and went back and tried the movie, it worked in all applications so....  Thanks!!

  • JennerDK Calculating status...
    Currently Being Moderated
    May 23, 2013 4:43 PM (in response to Joe Binks)

    This worked for me as well, but now it won't load the .srt subtitles files. Which it did before I changed the file. Does anyone know how to fix this?

  • William Stanton Level 1 Level 1 (0 points)
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    Oct 1, 2013 8:52 PM (in response to Bartbrn)

    I'm still mad about the "free email for life" situation…

  • William Stanton Level 1 Level 1 (0 points)
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    Oct 1, 2013 10:04 PM (in response to William Stanton)

    Anyway, I have a similar problem that's been bothering me. I'm stll using Snow Leopard v10.6.8 and .AVI files containing AC3 audio no longer work. The video plays but the audio is now just a buzzing noise… I've tried QuickTime Player, QuickTime Player 7 and QuickTime Player X. Even the official DivX Player now has this problem as well as MPEG Streamclip… VLC is the only thing left I have that can play them, but I've never liked it. I just want to use QuickTime, the only player I've used since the early 90's… Nothing on my system has changed in this time other than the available updates via Software Update control panel. Really the only thing I can think of that's actually been installed recently is the Security Update. I don't know if this is related or another problem all together but the left and right audio channels on my Mac are also now reversed (left is right and right is left)…When I brought it to the Apple store for a "genius" to look at it, their "fix" was to open the Audio MIDI Setup Application in the Utilities folder and change channel 1 to channel 2 and vice versa… A half-*** fix for something that's much deeper… The INPUT is still backwards… so any recordings I make of old records and cassettes still have their audio channels swapped unless I only listen to them on my Mac. What if I want to burn a CD and listen in the car? Go to CarToys and have my speakers on my Kenwood re-wired backwards too? W.T.F. Apple!

  • jpdemers Level 1 Level 1 (20 points)
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    Oct 2, 2013 4:10 AM (in response to William Stanton)

    W. Stanton:

     

    You might give this player a try:

    http://www.macblurayplayer.com/ac3-player-software.htm

     

    I can't vouch for it personally, and in any event I'm not running Snow Leopard so my experience would be irrelevant.

     

    The proliferation of video and audio standards and codecs is getting out of hand; they all "work" (more or less) for the users so there's no market force selecting for a single survivor.   AC3 is Dolby Labs' baby (or Frankenstein's monster); they've foisted it off on the users of their authoring software (because "better"), and it's becoming unavoidable.  AC3 files have six audio channels, to support Dolby's surround sound system. 

     

    There's plenty of stuff you can't do with OS-9, either . . . at some point you just have to upgrade.

  • William Stanton Level 1 Level 1 (0 points)
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    Oct 2, 2013 5:24 AM (in response to jpdemers)

    Update? Anyway I fixed my problem the old fashioned way, deleting the preferences file. com.cod3r.a52codec.plist located in /Users/~/Library/Preferences/

     

    More specifically just this:

     

    <key>attemptPassthrough</key>

    <string>1</string>

  • Jon Walker Level 6 Level 6 (17,520 points)
    Currently Being Moderated
    Oct 2, 2013 8:34 AM (in response to Bartbrn)

    Don't give up on DivX -- it's just a matter of getting the right codecs (like the updated a52AC3 and Perian) and don't automatically believe, as the a52 codec page tells you, that you have to ditch Quicktime's DivX codecs.

    Not sure if QT X works the same way as QT 7. Basically, for those who don't already jnow, QT 7 re-initializes the codec component list each time the app is opened. (That is why you have to close and reopen the app every time to make changes to your system's QT codec component configuration such as when performing codec conflict tests.) In any case, the order in which components are listed in this list depends on the order in which codec component were installed on your system. (Can't remember if this is a LIFO or FIFO ordering since it has been many years since I last had to re-install codecs or perform any conflict tests.) This is why, as the individual above pointed out, some users end up have problems when installing multiple codecs for the same compression format while other do not. The warning on the Perian site was originally designed to totally prevent any possibility conflict issues on a system—even when used by a novice.

     

    SJAUG.png

    iMac, OS X Mountain Lion (10.8.5), 3.4 GHz Quad Core i7, 12GB 1333 MHz
  • Jon Walker Level 6 Level 6 (17,520 points)
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    Oct 2, 2013 8:50 AM (in response to William Stanton)

    I'm stll using Snow Leopard v10.6.8 and .AVI files containing AC3 audio no longer work. The video plays but the audio is now just a buzzing noise…

    Again, for those who may not already know about this, this "noise" symptom usually indicates the audio is being output whithout first being decoded.

     

     

    I don't know if this is related or another problem all together but the left and right audio channels on my Mac are also now reversed (left is right and right is left)…When I brought it to the Apple store for a "genius" to look at it, their "fix" was to open the Audio MIDI Setup Application in the Utilities folder and change channel 1 to channel 2 and vice versa… A half-*** fix for something that's much deeper… The INPUT is still backwards… so any recordings I make of old records and cassettes still have their audio channels swapped unless I only listen to them on my Mac.

    Dis you (or the Apple "genius") also check both the Player built-in audio channel assignments/output channelization under both your own and a secondary user account to determing if this problem was local or global and/or determin if it was the file or the player malfunctioning?

     

    SJAUG.png

    iMac, OS X Mountain Lion (10.8.5), 3.4 GHz Quad Core i7, 12GB 1333 MHz
  • Jon Walker Level 6 Level 6 (17,520 points)
    Currently Being Moderated
    Oct 2, 2013 9:05 AM (in response to William Stanton)

    Update? Anyway I fixed my problem the old fashioned way, deleting the preferences file. com.cod3r.a52codec.plist located in /Users/~/Library/Preferences/

     

    More specifically just this:

     

    <key>attemptPassthrough</key>

    <string>1</string>

    Actually, this would not have been my first choice for a troubleshooting operation but appears to explain the AC3 audio problem mentioned above. My guess would be that this file became corrupted and was unconditionally bypassing the internal decoder software. The "passthrough" option is normally needed/used if you are sending the AC3 audio directly to the optical audio putput for external decoding. However, your fix indicates the issue was local and probably would have been caught immediatedly if you had tested to see if the issue was global to the system or local to the user account.

     

    Am curious. Did not understand if your L/R channel problem was limited to AC3 encoded audio or to all audio in general? When I originally read you comment, I had assume you were referring to non-AC3 audio which may have been a mistake. After reading this comment I amy now wondering if the secondary audio problem was only with AC3 encoded data and, if so, did the PLIST fix also eliminated the secondary issue. (I.e... for my own edification—just curious.)

     

    SJAUG.png

    iMac, OS X Mountain Lion (10.8.5), 3.4 GHz Quad Core i7, 12GB 1333 MHz
  • William Stanton Level 1 Level 1 (0 points)
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    Oct 2, 2013 10:50 AM (in response to Jon Walker)

    it wasn't my first choice/guess either… and you're right about catching it with another user. i actually made a second account and copied the component over and it worked. it was at that point that i checked the .plist file. what baffles me is how the passthrough option was turned on magically by itself. i don't even see any way to change that setting in the control panel… odd but glad it works now regardless. about the swapped audio channels though, yes they're still like that. and it's not just the line input and speaker output. for example, converting older lossless files from years ago as a test. the new .mp3 files encoded with itunes now have the channels reversed. i've confirmed this by comparing both files and sure enough sounds that were playing only on the right channel on the original files are now on the left channel of the .mp3 file and vice versa…

  • William Stanton Level 1 Level 1 (0 points)
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    Oct 2, 2013 11:11 AM (in response to Jon Walker)

    all audio sources are effected, not just a "player" for example: system preferences > sound > output: slide balance bar to the left and you hear the alert sound on the right and vice versa. i've tried recording with quicktime player, audio hijack, audacity and a few others and they all have the same result. even some youtube videos i've come across with comments like "my left ear is lonely" on some video with sound only on the right but it's backwards on my mac lol. i have an old maxell cd laser lens cleaner, the one with the speaker and channel tests on it. just listening to the cd, either from itunes, or quicklook, or anything else that can play a cd, even toast. the channels are swapped… drag the cd audio track to the desktop and open the .aiff file… swapped. hope you get what i'm saying now. and again apple's fix is to open the midi settings and reverse the channels. not a real solution as any audio files created on this machine will still have their audio channels swapped while listening to them elsewhere (unless you swap the speakers)!

  • Jon Walker Level 6 Level 6 (17,520 points)
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    Oct 2, 2013 11:36 AM (in response to William Stanton)

    all audio sources are effected, not just a "player" for example: system preferences > sound > output: slide balance bar to the left and you hear the alert sound on the right and vice versa. i've tried recording with quicktime player, audio hijack, audacity and a few others and they all have the same result.

    Did you ever reset the global MIDI settings modified by the Apple "genius" rep?

     

     

    what baffles me is how the passthrough option was turned on magically by itself.

    Not that unusual for the PLIST files to become corrupted. Though it usually results in things like the player crashes and such.

     

     

    i don't even see any way to change that setting in the control panel…

    It is usually done automatically by the system. For instance, the Apple DVD Player may change to "passthrough" when it opens if it sees an external decoder available. (E.g., I use an external Logitech amp/spearker system for playing AC3 6-channel audio from the DVD Player or VLC.) If QT is then opened but does not re-initialize the audio setting, notes the changed setting, and writes the modified "passthrough" setting to the PLIST file—well, that might explain the "magical" change... Or it could be either something as simple as flipping the switch setting when the PLIST is opened and writing the change back to the file when the QT app is closed or just flipping the setting switch when writing another change to the PLIST file. As the saying goes, "..it happens!"

     

    SJAUG.png

    iMac, OS X Mountain Lion (10.8.5), 3.4 GHz Quad Core i7, 12GB 1333 MHz
  • William Stanton Level 1 Level 1 (0 points)
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    Oct 2, 2013 1:01 PM (in response to Jon Walker)

    i don't have any special hardware hooked up to the mac so that's not it. i'm putting this one on the list of things apple does to sababage snow leopard in order to try to force users into upgrading to lion (see: webkit for snow leopard for more info). if i change the midi settings back, the sound output channels are still swapped. i left it backwards so audio that was encoded previously and also LIVE audio will at least playback correctly. in other words, i have to leave the left and right channels reversed in the midi setup app if i want to be able to move the balance slider to the left and hear the alert sound on the left channel…

  • Jon Walker Level 6 Level 6 (17,520 points)
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    Oct 2, 2013 6:39 PM (in response to William Stanton)

    i don't have any special hardware hooked up to the mac so that's not it. i'm putting this one on the list of things apple does to sababage snow leopard in order to try to force users into upgrading to lion (see: webkit for snow leopard for more info).

    Which probably implies the switch setting was corrupted during a normal read/write action.

     

     

    if i change the midi settings back, the sound output channels are still swapped. i left it backwards so audio that was encoded previously and also LIVE audio will at least playback correctly. in other words, i have to leave the left and right channels reversed in the midi setup app if i want to be able to move the balance slider to the left and hear the alert sound on the left channel…

    Must have misunderstood what you previously stated. Had assumed you had indicated that the Apple "genius" had reversed the left and right channels globally for your speaker configuration in the MIDI app...

     

    Sorry for taking so long to get back to you. Wanted to run some tests on my own system but could not find the file I had previously created from my Scotch DVD Masintenance Kit disc. Had to make another copy but had to wait for my conversion queue to empty before creating the replacement file. In any case, as a result of my tests, I was able to determine that the QT channel assignments about which I had previously asked but did not receive a response, functions as a soft switch—not a hard one. As a result, here is what I would recommend doing:

     

    1) Reset global system for normal playback (channel 1=Left, channel 2=Right) operation.

    2) Play your "Test" file in the VLC player (or QT X) app to determine correct orientation of Left and Right channels during "normal" playback.

    3) Open the same file in the QT 7 Pro player app and, if necessary, change the Left/Right channel assignments so that the Left and Right channel content play through the same Left and Right speakers as they do from the VLC (or QT X) media player.

     

    Theoretically, your problem should be resolved at this point. Basically, the VLC ( and QT X) player appears to ignore any channelization settings made in QT 7 Pro and plays the file back as it it were hardwired to the global MIDI speaker configuration. That is, whatever was recorded (correctly or incorrectly) to the left and right channels are played back through the speker setting controlled by the MIDI Setup app. However, QT 7 Pro can be set to rechannel (or reverse) the Left and Right channel assignments during QT 7 playback but these settings do not effect how VLC (or QT X) plays and ignore your MIDI Setup app speaker configuration. Since these tests were made on a Mountain Lion system, I then had to transfer the test file to my Snow Leopard platform to repeat them. The results were the same under Snow Leopard.

     

    Based on these results, it would appear that...

     

    1) If channels are reversed in either the VLC or QT X player, then you need to change your MIDI Setup app speaker configuration.

    2) If channels are reversed in the QT 7 Player, then you need to use QT 7 Pro to reset the channel assignments.

     

    SJAUG.png

    iMac, OS X Mountain Lion (10.8.5), 3.4 GHz Quad Core i7, 12GB 1333 MHz

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