Not able to do TrueHD and DTS-HD Passthrough (bitstreaming) on NUC6CAYH

Plex Players Desktop Players
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Server Version#: 1.15.1.710
Player Version#: 1.3.5.748-ff461e4e and 2.28.0.960-72d2c6aa

Hi,

I just replaced my two Raspberry Pi 3b+'s for Intel NUC6CAYH’s because of the lack of dts-hd and truehd bitstreaming on the pi’s to my Onkyo Receiver.
Installed the latest bios version and hdmi firmware on the NUC’s.
Installed Plexmediaplayer 1.3 via USB stick to Internal SSD in the nuc.
Dolby Digital and DTS are working fine, DTS-HD and TrueHD are giving noise or silence.
Tried the latest nightlies plexmediaplayer 2.28.0.960 version and is not working.
Tried OpenPHT 1.8.0.148 and is not working

For testing I also installed LibreElec 9.01 with plex plugin and DTS-HD and TrueHD passthrough are working fine, so it is not a hardware issue, but a plexmediaplayer software issue.

Is it possible to upgrade the LibreELEC version to 9.0.1 in the plex image?

Or what else can I try?

Best Regards,
Donald.

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Intel drivers?

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Which intel drivers? and where to put them?

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Ah, are you using the embedded versions? Do you have access to try a Windows installation?

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Embedded PMP needs to be rebased to LE9 to get the latest kernel to support the Apollo Lake NUC (as well as all the post Skylake NUCs). I have been testing against this issue since Jan 2017. The disappointing reality is that LE9 brings a lot of updates and changes to all the dependencies which requires a new version of mpv.

MPV itself also has a lot of new changes that bring regressions. The solution for an update is very unclear at this time. MPV is an entirely different animal from Kodi and LE9 was built for the latest Kodi 18.

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Yes, I’m using the embedded versions.
I can test a Windows installation too, no problem.

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Is it possible to upgrade MPV and LE inside the Embedded Image?
I’m now trying to build it myself on a Ubuntu 18.04 installation using instructions at: https://github.com/plexinc/plex-media-player

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Not as a drop in or anything simple like that. Rebasing ePMP to a newer LE is complicated to say the least.

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I finally got it working on Ubuntu Linux (kernel 4.15.0-46-generic)
Used the iso at: https://www.ubuntu.com/download/iot/intel-nuc-desktop#desktop

All passthrough (bitstreaming) including dts-hd and dolby truehd does work now.
Also Video Hardware Acceleration does work.

Used instructions at https://github.com/plexinc/plex-media-player

Had to do some additional setup to get it working:

Download hdmi firmware files (bxt_guc_ver8_7.bin and kbl_guc_ver9_14.bin) at:
https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/i915
and place them in /lib/firmware/i915

apt install linux-image-unsigned-4.15.0-46-generic
apt install vdpau-va-driver libvdpau-va-gl1 (to get hardware acceleration)

run Plexmediaplayer with:

VDPAU_DRIVER=va_gl plexmediaplayer

I created a file vdpau-intel.sh in /etc/profile.d with export VDPAU_DRIVER=va_gl in it so it sets it at boot.

And created a launcher which runs plexmediaplayer so it starts at boot.

We have a workaround now till the plex guys create a working embedded version for the intel nuc’s.

3 Likes
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I will give this a try as well. Thx for the legwork.

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No problem, just tried the new https://nightlies.plex.tv/public-test/plexmediaplayer/embedded-testing/2.29.0.964-dbe04ebb/PlexMediaPlayer-2.29.0.964-dbe04ebb.RPi2-arm.img.gz but audio passthrough still not working, only missing files in this image are bxt_guc_ver8_7.bin and kbl_guc_ver9_14.bin to get the audio passthrough working, is there a way to put those files in /lib/firmware on the embedded image, so it loads at kernel startup?

There is a symlink /lib/firmware/update in the image which points to the sdcard, I created a i915 dir there and put the files there, also tried /lib/firmware/update/intel as well and in the root of /lib/firmware/update but they won’t load.
Of which linux distro is the embedded image build on? when it is started it’s a read-only squashfs filesystem, when I read out the sdcard on another machine I don’t see the squashfs file anywhere, just a SYSTEM and SYSTEM.md5 and KERNEL and KERNEL.md5

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It is based off of LibreELEC

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But LibreELEC has already KODI in it.
Maybe I can install LibreELEC, remove KODI, and build PMP with the right firmware drivers for the intel nuc and voila it should be working, or am I thinking way too simple?

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Thats pretty much the procedure.

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