Passthrough can be either PCM (where the signal is decoded into analog data), or bitstream (where the encoded audio data needs to be decoded at the next device (Soundbar and/or AV Receiver).
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wow, thanks man. So easy to understand that.!
so the Xbox is sending the bitstream audio (i do have it set to bitstream) to my AVR to let my AVR do the decoding.
My setup: Xbox->LG CX->AVR. I canât connect xbox â AVR â LG CX because the AVR is not HDMI 2.1 compatible, so I would lose VRR and 4K 120hz.
On my testing, TrueHD passthrough works great for my LG CX. Unfortunately, the LG CX does not do DTS (decode or passthrough over ARC/eARC).
To get audio from DTS movies (no transcode) on my LG CX, I enable the DLNA server in Plex Server settings. Then I use the âMovies & TVâ app on my Xbox Series X to play the DTS movie through the Plex DLNA server. Multichannel PCM will show on the AVR (not DTS), but Xbox Series X is decoding DTS to PCM, so there is no quality loss from transcoding.
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passthrough is sending the audio bit stream from the file, directly to the receiver/soundbar without any modification, where the AVR/soundbar does the decoding from digital to analog.
PCM can be passed through, but if the original audio codec was not PCM, then that means the player or system is doing the decoding from, for example, truehd to pcm.
For example, the nvidia shield can do either pass through, or it can decode locally and send as PCM. This allows the shield to potentially direct play many more videos, since it can decode, for example DTS to PCM and send that to a tv/soundbar that doesnât support DTS. (the shield is doing the decoding, not your plex server)
appreciate the additional info
So for some reason I wanted to see the Xbox audio settings and I noticed it wasnât set to bitstream anymore. Couldâve been me messing with stuff some days back, but i had to set it to bitstream again. There are options of audio when setting to bitstream, do I choose Dolby Atmos or DTSX?
Now I need to test a movie with the settings corrected.
As far as I have seen, the xbox system settings for bitstream or PCM applies only to anything processed locally on the xbox (IE not passed through).
Normally, you would want this set to bit stream. If bit stream does not work, then most likely pass through will not either.
Pass through check box allows apps, such as plex (and I assume other streaming apps like netflix etc) to take advantage of pass through (which is is still a very new xbox feature, it was not possible at all until a month or so ago).
i know this is more about audio passthrough, but i played a few1080p videos with aac (stereo) yesterday (not as high bitrate/large files as my 4k content) and it was jittery on my Xbox Series X Plex app, however, played smooth on my $40 Tivo Stream 4K. Thought it was odd.
Just was thinking some of the jitter i got with the 4k Dolby Atmos files were related to high bitrate and file sizes. So now iâm thinking it might just be the plex app itself.
But no dts x with dlna right? Because of the metadata?
Iâm actually uncertain. Every DTS audio stream needs to have a DTS core, which is lossy 5.1, so at the very least it is decoding lossy 5.1 DTS core to PCM.
I donât know how accurate this is, but I donât think Xbox can decode more than DTS 5.1 lossy core, out of all the DTS variants. So that means DTS:MA and DTS:X is only passthrough.
And I donât know how the DTS Unbound Xbox app affects all of this as well. Based on the FAQ, it seems like it only enables DTS:X bitstream to an AVR or through eARC, which means it doesnât decode.
Iâve stopped using the xbox for trueHD-ATMOS/DTS-X pass-trough because of the desync of pass-trough and general out of sync audio.
I have have the feeling that it got worse since the fist beta test.
Itâs actually not that bad, but definitely not great at the moment. On initial playback you have to rewind or skip ahead to get audio and video to properly sync. Something I hope @Moussa and other devs can look into.
However once everything is synced properly playback is rather smooth (no dropped frames or glitches etc). Although Iâm getting issues with my Vizio Soundbar and TrueHD Dolby Atmos files at the moment (my soundbar keeps re detecting Atmos and causes a slight pause in audio).
So maybe itâs the Xbox, maybe itâs the TV (Vizio H1 Oled) or maybe the soundbar (Vizio 5.1.2 Atmos/DTS:X). Who knows?
Iâm sticking around with my Series X because when everything is properly synced, playback is great (especially sound quality). I hope soon this will be just as good as a Nvidia Shield Pro. Spec wise I see no reason the Series X/S is not equal or better than a Shield Pro.
All the bugs âseemâ Software related, so down the line Iâm betting Plex and Microsoft work together to make the experience much better. Audio Passthrough is still rather new for Xbox.
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Sadly passthrough really bad on the Xbox. I wonder if plex devs have a idea how to fix it
Mine works perfectly, whatâs the issue?
Hello everyone,
I have to agree with some user that plex still have several issues with passthrough. I have run several tests in order to be sure about the behavior of the app with several content and different audio protocols. I am sharing most of the issues below.
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4K HDR Movies with DTS-HA MA. After a while the movie freeze for maybe a second or more and the sound switch to PCM. Also i found a lot of frame drops.
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4K HDR Movies with multiaudio. If a movie support more than one audio format as an example let say ATMOS and DD, when I switch from ATMOS to DD the app switch from direct play to direct stream and i have no sound.
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4K HDR Movies in MP4. Unable to play.
The strange thing is that if I disable passthrough the playback is pretty smooth with everything.
I am seeing similar audio drop outs when playing 4K HDR content with TrueHD Atmos encoded audio.
When I play a 4K HDR TrueHD 7.1 Atmos file (bitstream with passthru etc⊠all enabled), my soundbar (Samsung Q80T) correctly recognizes the Atmos data and the sound plays fine for about 5 mins and then just cuts out and I have to stop/resume the file to get sound back.
When I play a similar 4K HDR eAC3 5.1 Atmos file it plays perfectly, no drop outs no issues.
I assume this is a symptom of the new Xbox plex capability to passthru TrueHD content given it is only affecting TrueHD audio streams.
Hi all,
I have just installed the newest version of the DTS app and it seems 4K HDR DTS-HD MA remux files works! I hope the pgs subtitle transcoding issue will also be solved soon.
Iâve tried a 4K HDR HEVC MKV with 5.1 PCM. Plex is transcoding audio to AAC on Xbox Series X.
Does Plex support passthrough for 5.1 PCM on Xbox Series X?
ID : 2
Format : PCM
Format settings : Little / Signed
Codec ID : A_PCM/INT/LIT
Duration : 2 h 30 min
Bit rate mode : Constant
Bit rate : 4 608 kb/s
Channel(s) : 6 channels
Sampling rate : 48.0 kHz
Frame rate : 25.000 FPS (1920 SPF)
Bit depth : 16 bits
Stream size : 4.83 GiB (7%)
Title : LPCM / 5.1 / 48 kHz / 4036 kbps / 24-bit
Language : English
Default : Yes
Forced : No
My setup: Xbox->LG CX->AVR. I canât connect xbox â AVR â LG CX because the AVR is not HDMI 2.1 compatible, so I would lose VRR and 4K 120hz
EDIT___
Instead of trying to get PCM multichannel passthrough to work, I ended up just converting movies with DTS-HD MA audio tracks to TrueHD using FFMPEG for lossless to lossless conversion. Now I can get lossless audio passthrough from movies originally with DTS-HD MA tracks on my LG CX with Plex on Xbox Series X.
ffmpeg -i source_movie_with_DTS-HD_MA.mkv -map 0 -c copy -c:a:0 truehd -strict -2 output_movie_converted_to_TRUEHD.mkv
I think this is a bug?:
When viewing a 4K HDR MKV of a high frame rate video (e.g. Gemini Man), the display does not switch to 60 hz. Instead, it triggers game mode (ALLM) on my LG CX, which enables 120 hz with VRR.
Other MKVs with 24 FPS switches the display to 24 hz. So shouldnât it switch the display to 60 hz?
LG CX and Xbox Series X. Allow Display Mode Switching is enabled.
I recently got an Atmos sound system. TV doesnât support eARC. No problem, I connected the system as follows:
Xbox One X â Sound system â TV.
Dolby Atmos is installed on the Xbox & enabled.
HDMI Audio is set to Bitstream out.
Bitstream format is Dolby Atmos for home theater.
Allow passthrough is checked.
When I launch a video the sound system detects Atmos.
HOWEVER when looking at playback information in a 7.1 TRUEHD movie I get the following warning:
Cannot direct stream with protocol: dash, coded truehd. Reason: truehd is only available with Direct Play.
Notice how it says âdashâ, because looking at the screenshot, you can clearly see itâs going over âhttpâ:
What am I missing?
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