I'm not sure if this is the right place to discuss this, so please move this to the right sub-forum if necessary.
I'm trying to play back a MKV with dual TrueHD audio streams in it and a video stream encoded with x264 high profile Level 4.1 (1080p, ~9Mbps) on my Nvidia Shield TV (2015, latest Experience Upgrade/Patch). One of these audio tracks has Atmos info in it, while the other is plain TrueHD without Atmos, both 7.1 Lossless.
As you might have guessed: I'm not able to get the playback started, at least not with bitstreaming and direct play on on the Shield TV (transcoding sure works).
As soon as I remove one of the TrueHD tracks, the playback starts just fine (no matter what track, they both work; tested both respectively). Even with one TrueHD track and one DTS track, playback with bitstreaming and direct play is fine and I can switch audio channels no problem.
But as soon as the second TrueHD track is in the file, playback wont start. The movie seems to start playing, but the time counter stays at 0:00 without video nor audio getting played back (allthough it says direct play in the upper left corner). If I jump to a chapter, it displays the first frame of that chapter, but won't start playing from there. It seems that the bitstreaming handover to the receiver fails with the second TrueHD track present.
I need to mention that the Plex Media Server seems to correctly recognise the file and provides all track information correctly in the UI, even with both TrueHD tracks in it. The file itself with both TrueHD tracks in it also plays fine on Windows with MPC-HC, so I guess the file itself is valid.
Is this a bug in Plex or is there any known limitation to what the Shield can handle regarding audio tracks and MKVs that could be the cause of this? Or maybe is dual-TrueHD not officially supported within MKVs?
Any hint would be appreciated.