[VonMagnum]

Is there a way to preserve Auro3D audio in a pure PCM format (i.e. Red Tails doesn't wrap Auro3D in DTS-MasterHD like other discs, but has it as pure PCM on the disc).  If I use MakeMKV and dump the disc with PCM, it won't see the Auro3D track on my Marantz receiver (the DTS wrapped ones work fine).  I'm not sure if the problem is MakeMKV or KODI or something else.  It only sees PCM 5.1, not Auro3D signal at all.  I have to play the disc via BD player to get it.   Auro3D is encoded in the 24-bit PCM file in both cases, but I think the multi-channel output of KODI may be the issue.  I'm not sure how a BD player does it differently (does PCM "bitstream" ?  Passthrough setting makes no difference.  Thanks.

Have you selected Best Match or fixed your PCM output in Kodi's System Audio settings. Optimised isn't always a good fit. 

I've tried all three.  It doesn't work under any of them.

AIUI Auro3D is carried in a PCM signal - which wouldn't be described as being 'bit streamed or passed through' as it's not a compressed format like DD/DTS/TrueHD/DTS HD etc. Also make sure your volume is at 100% in Kodi?

The Marantz 7010 receiver behaves a little differently with "bitstream" versus "multi-channel PCM over HDMI".  You CAN apply a Dolby Surround Upmixer or Neural X or even the Auro3D upmixer to multi-channel PCM, but I don't think it normally detects encoded signals over multi-channel PCM (i.e. it probably expects PCM is already decoded by the player as that is normally the case whether through a PS4 or KODI, the multi-channel output is typically a bunch of already decoded channels).  I assume something is different about Auro3D over PCM from say a Blu-Ray player that it's able to pick it up as opposed multi-channel output.  My PS4 can decode Dolby or DTS to multi-channel PCM, but if it does so, the Atmos or X signal is not passed through.  I just get 7.1 at most.  The LG UP875 UHD BD player cannot and does not decode DTS or Dolby to multi-channel PCM, but it can play Auro3D that's encoded in PCM.  Maybe there's no fundamental difference other than the decode versus just passing it on?  If so, then that would imply that Auro3D "should" be able to be played back via a MKV file, but something is going wrong along the way that it's not seeing the data.  I figured maybe the data was damaged/destroyed when I tried encoding Handbrake to FLAC 24, but it didn't detect it on the MakeMKV direct rip either and I can't get a more direct PCM dump than that.

I do know I tried turning off the "keep audio device alive" and "send inaudible noise" type settings in case they somehow interfered, but it still didn't detect it.  There's always a chance MakeMKV is somehow destroying the signal also.

I'm guessing there is some tunnelled audio data in the PCM signal that can be destroyed?

I believe the Auro3D "height channels" are stored in the least significant bit(s) of the 24-bit multi-channel PCM signal.  I think the base/bed channels are played from the 5.1 PCM that's already there.  This then gives you 5.1 + however many height channels that are included (4-6 typically for Auro 9.1 to 11.1 while Auro 13.1 adds rear lower surrounds as well).[/quote]