Plex play 4K HDR and DTS-MA?

Software & Operating Systems Open Source & Web-Based
1

Calling on the Plex gurus … experiencing frustration and search engine fatigue.

I’m trying to learn how to playback a media file that’s encoded with HDR and a DTS-MA 7.1 sound track, using Plex Media Server. It seems Plex is not up to the job unless I buy an NVidia Shield, which appears to be the developer’s preferred streaming box.

For streaming hardware, I have 2016 LG Smart TV (WebOS 3.0), a latest-gen Chromecast Ultra and an old Xbox One S. According to my experience and what I’m reading online, none of these devices seem capable of the task, using the app provide by Plex. Just about every thread I’ve read is either unanswered, or someone from Plex saying “buy an nvidia shield”.

The Plex WebOS app won’t do HDR - don’t know why, same goes for the YouTube webos app. However Netflix and Amazon apps both do HDR fine on the display.
The Chromecast app won’t do DTS-MA or Dolby Atmos - anything more than 5.1 gets down-mixed on the server.
The Xbox app doesn’t seem to do HDR either, limited to Plex.

For decoding audio, I have an Onkyo 4k receiver which supports just about every audio codec under the Sun. I don’t need the TV, Chromecast or Xbox to decode audio at all, just pass it through.

TV is connected to the Onkyo using HDMI-ARC, and I have confirmed, it supports more than 5.1 audio

Xbox is connected to the Onkyo and does DTS-MA when playing back a UHD Bluray disc.

Do I need to burn the media file to a bluray and play it on the Xbox? Is there any way to stream it? Any suggestions other than buying the Nvidia streamer?

2 Likes
2

Force transcode the video to as high of a bitrate as possible and passthrough audio?

My experience with built-in Plex apps and consoles is pretty bad, and my only solution was also getting a shield haha.

3

AFAIK Plex will only do HDR when the video is being played direct (no transcoding) as it has no built in tone mapping functionality. But this is still dependant on what the player does. As for audio you will need to set the player to use bitstreamed audio so it passes it to the receiver. But you won’t be able to do this over ARC unless you have EARC.

4

This is actually not true anymore. HDR can be tonemapped when downscaling or transcoding.

Edit it is HDR to SDR Tone Mapping so no go.

2 Likes
5

So… if I plug the ccu into the receiver instead of the TV, I might get my Atmos?

Any tips on disabling the transcode on the plex server, so it sends the full audio bitstream to the ccu?

6

There’s really no reason why it couldn’t do HDR while transcoding, all it has to do it pass the metadata but that’s just what I last heard.

Yeah plug it in to the receiver, or try it on the xbox. For video you just set the quality to play original quality or whatever it’s called, so it’s not doing any transcoding. For the audio there should be a setting in the player’s settings to enable bitstream audio.

7

directplay and directstream are both enabled. I need to get into the logs again, but to paraphrase plex server complains audio format not supported, transcoding … I don’t care if the ccu can’t decode atmos, I don’t expect it to.

8

You may also need to enable bitstreaming on the device itself

9

I’ve resorted to playing HDR using minidlna and the “player?” built into the tv, instead of plex which is (was) my go-to solution on my old 1080p non hdr tv.

I too have enough tv/receiver hardware to not need any transcoding, it was just hard convincing plex of that.

Also, I found that enabling/disabling subtitles somehow made a difference on a Chromecast ultra of all things. (contents of a transparent div that is the subtitle box, crazy).

I heard that kodi running on an odroid n2+ might be the way to go these days for your UHD HDR10+/DV ; HD audio streaming, but haven’t tried it personally (since minidlna is working for me).