Had questions myself about how well the new Series X plays content, saw there were several questions in threads here too, so have included my brief tests below… Please do not buy a Series X based off of these test wait for more feedback from other users too…
Remote Tests: Server Based in Netherlands - Player in the UK
All tests were done with varying bitrate 4K HDR movies, i have not included subtitle tests as these are still unplayable.
This was my long shot one, no support for TrueHD 7.1/Atmos still. Considering it was transcoding the audio and has a high bitrate i was surprised it only buffered a few times during the movie. Still to many times for me though…
Same movie as above with high bitrate but with direct play of audio. Played better than the version with transcoding audio, but still left alot to be desired. Going to be a way off before we can remote play high quality 4k hdr remuxes.
Slightly lower bitrate movie, with DTS this time. Still needs to transcode the audio (I need to play around with the dts app and the bitstream more for 100% confirmation). As mentioned only a slightly lower bitrate so no surprise their wasn’t much improvement over the 1st video.
A very low bitrate 4K HDR movie backup that needed transcoding, but worked flawlessly.
Played exceptionally well, apart from half way through when it decided to go on a buffering rampage for 5 minutes. (I believe this might have been my internet connection though.)
Considering its still a fairly high bitrate and transcoding the audio, it was flawless. No issues what so ever.
TLDR for Remote Streaming: Atmos doesn’t work still, neither do 4K HDR with Subs. The sweet spot for me with the highest bitrate (still not high enough for my tastes) was between 50Mbps and 100Mbps.
Local Network Tests:
Coming over the coming days, not hugely different from remote so far.
Any questions shout or more tests ill give them a go.
My understanding from reading other threads, and trial and error, is that the xbox app will play the 4K video part directly but only if there is a compatible audio track, i.e. not dts, etc. The xbox plex app will not play audio of DTS, Atmos, True-HD (7.1), etc. Plex blame Microsoft blocking it. And I expect if MS were to be asked, they’d blame Plex.
Plex: please can you comment on this based on 2021?
Further info
When there is an audio track (not playable directly in xbox) it is transcoded to AAC.
Also the video is also transcoded to X.264 (1080P). As you can imagine this will cane the CPU of your PMS!
For example, I have a movie as an MKV file with a HEVC (x.265) HDR 10 video and 2 sound tracks of Dolby TrueHD with Atmos or DD AC3. If I select the Atmos audio it does not play in 4k but 1080P and the audio is AAC - both transcoded. When I select the DD AC3 audio, it plays the 4K and AC3 audio. Not ideal.
For my setup I was hoping to be able to configure a PMS profile for the Xbox so it at least transcodes to AC3 rather than AAC. This is because my receiver does DD.
The behaviour in your screenshots seems to match testing I’ve done recently on the ‘Plex for Xbox’ player app on Xbox One X as well.
Testing a good sampling of 4K HDR mkv files with various full bitrates and audio formats, here are my observations.
For HD audio formats, (TrueHD, MTS-HD, etc.), audio will be transcoded to AAC, with the 4K HDR Main 10 video direct streamed. If audio is AAC or AC3, the audio and video will both be direct played.
Specifically only for files with TrueHD 7.1 Atmos audio being transcoded to AAC, the direct streamed 4K HDR Main 10 video will stutter and display random multi-coloured digital artefacts when playing back. My server CPU usage remains very low during this audio transcoding and I’m on a gigabit wired network playing the files from the local network, so not a network or server capacity issue. This seems to be an issue with the ‘Plex for Xbox’ app. If an AC3 audio track is available to alternatively select from these files (or remuxing/converting the audio to AC3), these files will play smoothly without issue in 4K HDR.
With regards to sub-titles, if I select the sub-titles from a ripped MKV file, instead of direct playing or direct streaming the 4K HDR Main 10 video, under default settings Plex reverts to transcoding the video to 1080p, burning in the sub-titles (my server can’t handle this transcoding from 4K, so the video becomes unwatchable with 80-100% cpu usage). I found the solution for this issue as follows: from playing back an individual file in the ‘Plex for Xbox’ app, when selecting subtitles, choose the option at the bottom to “search” for additional sub-titles, select a suitable SRT type file, and from options change the ‘burn subtitles to video’ option from automatic to never or ‘only for image type sub-titles’. This results in direct streamed 4k video playback, with visible sub-titles, provided the source audio is not TrueHD 7.1 Atmos (as explained as problematic above). I tested this sub-title solution for few files and this worked for each one.
Finally, now that I understand the absence of HD audio passthrough support via the Xbox for Plex app, I’m aiming to switch my Plex player to NVDIA Shield Pro 2019 so audio can be direct played and sent to my AVR.
Hi, having read your test results, I’m glad I was not missing something.
Not sure what tv you have? My oled LG TV, I have installed the plex app for LG. This has direct played All media (zero transcoding) I have passed on it. DTS, DTS-HD, Atmos. Even the receiver detects the bitstream signal from the TV plex and plays as expected. On the visual side it detects hdr. The plex server is not overloaded.
As a result of this I no longer use plex for xbox. Which is a shame.
