berndporr

Q: no sound when creating an itunes itmsp 5.1 package

Hi all,

 

I'm using compressor

 

I've got an uncompressed quicktime file which contains 5.1 sound (L,R,C,LFE,Ls,Lr) and with that I make an itunes package.

 

I export it as SMPTE 5.1 sound with additional stereo downmix: (L,R,C,LFE,Ls,Lr,Lt,Rt).

 

When I play the resulting Pro Res 422 HQ the audio is just zero / silent.

 

I'm sure it worked two weeks ago but now it's just silence.

Mac mini, iOS 9.2

Posted on Feb 3, 2016 1:03 AM

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Q: no sound when creating an itunes itmsp 5.1 package

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  • by berndporr,

    berndporr berndporr Feb 3, 2016 1:06 AM in response to berndporr
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    Feb 3, 2016 1:06 AM in response to berndporr

    ...I should add that in the compressor preview the sound plays fine and the downmix to stereo is also perfect. Just the pro res output is silent.

  • by berndporr,

    berndporr berndporr Feb 4, 2016 11:14 AM in response to berndporr
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    Feb 4, 2016 11:14 AM in response to berndporr

    In order to test if it has something to do with the iTunes package management I've just created a Pro-Res 422 HQ file from the uncompressed 5.1 quicktime file and again there is no audio in it. The subtitles seem to import fine but there is no audio.

    Note that again the quicktime is 5.1 (L R C LFE Ls Rs) and I've exported to Pro-Res 422 HQ with SMPTE audio (L R C LFE Ls Rs Lt Rt).

  • by berndporr,

    berndporr berndporr Feb 4, 2016 12:13 PM in response to berndporr
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    Feb 4, 2016 12:13 PM in response to berndporr

    If I do "copy audio tracks from source" then it works.

     

    Conclusion is: when using the new audio options (converting 5.1 to SMPTE, etc) which allow for example the matrix stereo down mix then there is a problem.

  • by berndporr,

    berndporr berndporr Feb 4, 2016 12:50 PM in response to berndporr
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    Feb 4, 2016 12:50 PM in response to berndporr

    I've narrowed it down to the following problem:

     

    5.1 (L R C LFE Ls Lr) --> SMPTE (L R C LFE Ls Lr Lt Rt)

     

    just creates silent audio in the pro res output.

     

    What it should do: copy the first 6 channels over and then calculate the matrix stereo channels Lt Rt. None of this happens. I'd call it a bug.

     

    Apple: it would be great if you could fix it really soon. I'd like to submit my film to your aggregator. Otherwise I can just submit in stereo (which works).