It doesn’t matter if you do.
Welcome back for round two ladies and gentlemen because 8.29.0 just broke OPUS transcoding…again.
So, I just installed the Plex 8.29.0 update on my Shield TV through the Play Store and my sound is messed up…again!!! The changelog for the update says “prefer non-PCM output when playing over ARC” so clearly the Devs have been messing with the way Plex handles sound output.
Hardware: nVidia Shield TV Pro;
Shield Android TV SW v8.2.3(32.6.518.0) (Android TV 9) (I haven’t updated to SW v9)
Plex player version: 8.29.0.30433 (b3774acd)
Plex media server version: 1.25.5385
PMS running on my Shield is pulling content from a NAS and the Shield is connected via HDMI to my Sony AV receiver. The Shield/Android TV is set to auto detect compatible audio formats reported by the AV receiver and the Shield is showing that DD/AC3 and DTS are both supported (turned on) whereas all other audio formats are turned off.
The problem: Even though my AV receiver reports that it only supports AC3 and DTS, the problem has returned in that;
(1) OPUS is once again NOT being transcoded to AC3 or DTS, resulting in stereo PCM, and
(2) since Plex thinks my system supports OPUS it’s once again transcoding AAC to OPUS, resulting in stereo PCM. Previously AAC was transcoded to AC3.
Plex Devs, here’s a rundown of the Plex’s behaviour in the hopes that it helps you identify the problem.
Within Plex settings;
- If I disable passthrough:
-AAC 5.1 comes through (to my Sony AV receiver) as stereo PCM. Plex playback info reports “Direct Play (AAC 5.1)”)
-AC3 5.1 comes through as stereo PCM. Plex reports “Direct Play (AC3 5.1)”
-DTS 5.1 comes through as stereo PCM. Plex reports
-OPUS 5.1 comes through as stereo PCM. Plex “Direct Play (OPUS 5.1)”
- If I set passthrough to HDMI:
-AAC 5.1 comes through as stereo PCM. Plex reports “Direct Play (AAC 5.1)”
-AC3 5.1 comes through as AC3 5.1. Plex reports “Direct Play (AC3 5.1)”
-DTS 5.1 comes through as DTS 5.1. Plex reports “Direct Play (DTS 5.1)”
-OPUS 5.1 comes through as stereo PCM. Plex reports Direct Play (OPUS 5.1)
- If I set passthrough to Optical and enable only AC3 optical encoding:
-AAC 5.1 comes through as stereo PCM. Plex reports “Transcode (AAC - OPUS)”
-AC3 5.1 comes through as AC3 5.1. Plex reports “Direct Play (AC3 5.1)”
-DTS 5.1 comes through as stereo PCM. Plex reports “Copy (DTS)” and ‘transcode reason’ says “DTS audio is not supported by the device” (and yet Plex is outputting DTS anyway)
-OPUS 5.1 comes through as stereo PCM. Plex reports “Copy (OPUS)” and ‘transcode reason’ says “unable to direct play as OPUS is not supported on this device” (and yet Plex is outputting OPUS anyway)
- If I set passthrough to Optical and enable both AC3 and DTS optical encoding:
-AAC 5.1 comes through as stereo PCM. Plex reports “Transcode (AAC - OPUS)”
-AC3 5.1 comes through as AC3 5.1. Plex reports “Direct Play (AC3 5.1)”
-DTS 5.1 comes through as DTS 5.1. Plex reports “Direct Play (AC3 5.1)”
-OPUS 5.1 comes through as stereo PCM. Plex reports “Copy (OPUS)” and ‘transcode reason’ says “unable to direct play as OPUS is not supported on this device” (and yet Plex is outputting OPUS anyway)
So even though my AV receiver reports that it only supports AC3 and DTS, the problem has returned in that; (1) OPUS is once again not being transcoded to AC3 or DTS, resulting in stereo PCM, and (2) since Plex thinks my system supports OPUS it’s once again transcoding AAC to OPUS, resulting in stereo PCM.
All I want is for:
AAC 5.1 to be transcoded to AC3 5.1 or DTS 5.1
AC3 5.1 to stay as AC3 5.1
DTS 5.1 to stay as DTS 5.1
OPUS to transcoded to AC3 5.1 or DTS 5.1
Other newer audio formats (DTS-HD, E-AC3, Atmos, etc) to be transcoded to AC3 5.1 or DTS 5.1
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@sixones is working on this.
That’s good to hear. Hopefully the fix comes soon because as it is I’ve had to go back to using KODI.
Glad to hear this is being looked into, as I’m having similar issues.
My setup consists of a Shield TV sending audio to my tv via HDMI, which is connected to my 5.1 surround sound via optical.
My TV is only able to pass AC3 to the receiver so I would have optical passthrough with AC3 selected in the Plex Android TV app. This would allow AC3 to pass through, and if I played media that didn’t have AC3 tracks, it would be transcoded accordingly to make that audio work with my setup.
Since the latest update, this functionality has broken and now the audio sounds god awful as my receiver tries to piece back together the 5.1 audio from two channels it’s getting from the Plex app.
What’s mind boggling to me is that I can cast the same movie from my phone to the same Shield TV and the audio transcodes correctly without even needing to fiddle with any settings. Is the Android TV app just incapable of handling audio the same way as casting from the mobile app?
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You can disable auto updates and side load 8.28.0 (if you don’t want to use Kodi) for now until they fix this - that version still works for me for AAC passthrough.
I posted this problem as well the 26th of January.
https://forums.plex.tv/t/version-8-29-broke-aac-passthrough/772996
Question: Which passthrough method do you normally use? HDMI or Optical?
I was looking around for the 8.28.0 apk but never found it. KODI is working very well though, fortunately. I’m actually surprised at how quickly KODI launches videos compared to how long it takes PLEX. PLEX actually seems overall very sluggish compared to KODI.
I normally have passthrough set to optical and both AC3 and DTS enabled. Usually this would mean that anything other than AC3 or DTS would be transcoded to AC3 or DTS (surprise surprise) but that’s no longer the case since 8.29.0.
So I’ve just installed the latest PLEX update 8.29.1.30697 (420a2e38) through the Play Store and the sound issue has NOT been fixed. Very disappointing. Fortunately KODI is working well though.
Anybody know where I can get the PLEX 8.28.0 apk so I can rollback to a version that actually works?
Nevermind. Found it on APKmirror. I had to uninstall 8.29.1 first then I installed 8.28.0 from USB. Re-linked my account and my library was already good to go.
I had to re-enable passthrough via optical and then select AC3 and DTS, and now transcoding is working properly again - AC3 and DTS play natively, eAC3, AAC, OPUS, TrueHD are transcoded to AC3. Only issue is DTS-HD is not transcoded, it comes through as "Copy (DTS-HD) even though DTS-HD is not an enabled audio format within Android settings. If I disable DTS within Plex > settings > optical encodings then DTS-HD is decoded to AC3. But unfortunately that means DTS, which my receiver supports, also gets transcoded to AC3. What’s weird though is that when passthrough is set to HDMI, DTS-HD 7.1 direct plays just fine. Oh well that’ll have to do for now.
For anyone interested in downgrading their Shield to Plex 8.28.0, the Shield uses the arm64-v8a version.
8.28.0 for arm64v8a can be found here:
I already have auto-update disabled (within the Play Store), but I usually install Plex updates without any qualms. No more Plex updates for me though.
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Do you do anything special for Kodi to passthrough AAC properly?
I’ve enabled passthrough in Kodi settings but it comes through as stereo.
AAC → AC3 5.1 transcode works fine on Plex 8.28.0 with Optical passthrough.
- I actually find it weird that it only works with optical.
My setup:
Shield → TV → Sonos soundbar
APKMirror is nice, you can also use this in the future: https://m.apkpure.com/plex-stream-movies-live-tv/com.plexapp.android/versions
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I think I can help you here. In order to get KODI to transcode AAC 5.1 to AC3 5.1 you have to tell KODI that your system only has 2.0 channel audio. Weird, I know.
Go to KODI > settings > System > Audio, then set number of channels to “2.0”. I have ‘output configuration’ set to “Best match”. As for the transcoding settings, well within my Shield settings, Android TV auto detects that my AV receiver only supports AC3 and DTS formats (even though the receiver’s specs say it supports other formats but oh well), so within KODI’s “Audio Passthrough” settings I only have AC3 and DTS enabled. Specifically, I have:
Allow passthrough = enabled
Passthrough output device = AudioTrack (IEC), Kodi IEC packer (recommended)
AC3 capable receiver = enabled
-Enable AC3 transcoding = enabled
E-AC3 capable receiver = disabled
DTS capable receiver = enabled
TrueHD capable receiver = disabled
Atmos capable receiver = disabled
Despite telling KODI that your system only supports 2.0 audio, 5.1 audio should still come through as 5.1. Hopefully that will do the trick for you.
Thanks!
Thanks for the heads up about 8.28.0! Rolling back and turning off auto updates got me transcoding to AC3 as needed again. Hopefully the devs are paying attention and can get a fix pushed out soon.
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After seeing the notes for the latest beta release, it looks like they’re going the wrong direction here.
“Player: ensure optical passthrough is restricted to stereo PCM”
Can someone at Plex explain this decision? If I wanted my media to play in stereo, I wouldn’t be using passthrough in the first place.
I think that restricting optical passthrough to stereo will mean that 5.1 AAC and OPUS is unable to passthrough as 5.1 PCM, and, as such, will be forced to be transcoded to AC3 5.1. At least I hope that’s the logic. But I guess that means 5.1 AC3 and DTS won’t passthrough?? hmmm 
Ah yep, I must’ve misinterpreted the patch notes. I blame a late night working on my homelab…
Since the apk was available, I went ahead and sideloaded it onto my Shield this morning to give it a try. Mine is working as intended on this version with AC3 selected in the optical passthrough. So now audio encoded in AC3 is passing through as expected and everything else transcodes on my server and is sent to the receiver correctly. Whew!
Hopefully this means that update will fix the issue for your use case as well.
The same thing has happened on Google TV as well. Telling it that I run optical and checking AC3 as valid format previously transcoded EAC3 → AC3 (whereas ARC setting transcoded to stereo OPUS at an insanely low volume), but since some update ago, this got all ■■■■■■ up.
Breaking stuff occasionally is acceptable if there is actually some attention to fixing it, but with Plex it’s always a ■■■■■■■ battle to get acknowledgment and fixes…
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Finally! Good to hear. I’ll keep an eye out for the 8.30.0 stable version then.
Agreed. This is the sort of stuff that wards me off purchasing a Plex pass (I’ve come close to purchasing one in the past but then a dodgy update breaks crucial functions).
I would have a lot more confidence that a Plex pass is a worthwhile purchase if I, as a user, was given;
(i) the ability to control which audio formats are passed through and which are transcoded, and
(ii) I’m not sure whether Plex can even transcode to DTS, but if so, it would be great to be able to control what audio format Plex transcodes to (i.e AAC > AC3, or AAC to DTS, DTS-HD > AC3 or DTS-HD > DTS).
At the moment we’re at the mercy of whatever the devs have decided to try and we’re left stranded when they break things. I gather that most people are basic users and an “auto” approach is best for them, but “Advanced” settings should unlock the ability for users to tinker, imho.
