Server Version#: 1.16.2.1321
Player Version#: 7.16.1.10610
Just got an Amazon 4k Fire stick (2018) to use a player. Overall I’m pleased, but it won’t direct play aac audio and the plex app says the aac is not supported on the device. I checked with the specs and aac is definitely supported on the device.
Is there something I’m missing?
AAC should direct play. AAC should decode to another format (PCM, AC3, etc) on the FireStick, then pass over HDMI to attached TV/receiver/etc (based on how my AFTV Cube acts).
What is currently happening with the audio? Transcoding? If so, to what format?
Please pull the Plex XML, save as a text file, and attach to the thread. Alternately, analyze with MediaInfo and attach text output. See Investigate Media Information & Formats. Looking for info such as 5.1, 7.1, bitrate, depth, etc.
To what is the Fire stick attached - TV, receiver, etc? Make & model? Needed to check on supported audio formats (AC3, EAC3, PCM, etc).
How do you have the Fire Stick audio configured - the stick itself, not the Plex app? The exact working varies by FireStick device, but the options are generally 1) best available, 2) force AC3, 3) force EAC3, 4) force stereo.
Need to make sure the FireStick configuration aligns with the attached device (ex: don’t want FireStick forcing audio to EAC3 if it isn’t supported by attached tv/receiver/etc).
How do you have the Plex app audio configured? Is passthrough enabled? Ideally, set the audio & video to max/original quality (unsure of exact wording), and have passthrough enabled over HDMI.
Thanks for the response.
The audio is transcoding from AAC 5.1 to AC3 5.1
Fire stick is plugged directly into Samsung TV un60ju7100. Hard to tell what formats are supported from samsung website. It just says DTS and Dolby Digital Plus.
On my Fire Stick, have audio set to best available.
Plex quality is set to maximum. Passthrough is enabled.
firestick aac file.txt (12.9 KB)
The Fire stick cannot passthrough AAC 5.1, so it transcodes it to a format it can. Otherwise you would only get stereo.
Here on the Amazon specifications it says it supports AAC up to 6 channels. Am I to understand the Fire Stick doesn’t passthrough a format it supports?
Yup. It can decode up to 6 channels locally but it can’t passthrough.
So Plex Media Server is transcoding the audio? It is not decoding on the Fire Stick?
I’m seeing something different.
When I play a video with AAC 5.1 audio on my Cube, PMS always reports direct play. The audio is decoded on the Cube to AC3/EAC3 depending on the setting of the Fire TV audio.
Test 1: AFTV Cube <–HDMI–> LG B7 OLED
Play video with AAC 5.1 audio three times. Once each with Fire TV audio set to 1) Best Available; 2) AC3 only, 3) EAC3 only. Audio plays through the TV speaker w/o issue each time. PMS reports Direct Play each time.
Test 2: AFTV Cube <–HDMI–> LG B7 OLED <–HDMI ARC–> Denon 4300
LG set to pass audio to Denon via HDMI-ARC.
Cube set to Best Available
Play video with AAC 5.1 audio
PMS reports Direct Play
Denon receives stereo audio from TV. Display says “Dolby Surround”
Cube set to Dolby Digital only
Play video with AAC 5.1 audio
PMS reports Direct Play
Denon receives Dolby Digital 5.1 audio from TV.
Cube set to Dolby Digital Plus only
Play video with AAC 5.1 audio
PMS reports Direct Play
Denon receives Dolby Digital Plus 5.1 audio from TV.
PMS v1.16.3.1402-22929c8a2 on DS918+
Plex client v7.16.1.10610 on AFTV Cube
Turn off pass-through in the Plex app. Then we will send AAC5.1 to the device and let it do it’s own thing.
Wait. We turn off passthrough to get the app to send the data through to the Fire Stick?
Thanks for all the replys.
Forcing any format in the Fire Stick settings didn’t affect the stream. Disabling passthrough doesn’t affect the stream.
I thought AAC was a pretty common format. Even the Plex app on my Samsung TV (which the 4k stick is attached) can decode and direct play AAC no problem, and I got the 4k stick as an upgrade to the Samsung OS streaming. It is better, in all cases except AAC audio.
I guess I’ll just move on.
AAC 5.1 is NOT a standard format - usually only found in Pirated material.
How do most people deal with it? I assume ‘most’ let Plex transcode it to something compatible, but ‘most that want it to direct play’ convert it to AC3 5.1 and pack it into an MKV file along with those external subs - if they’re UTF-8 and if they aren’t, they soon will be.
The ONLY thing I let Plex transcode is audio to my phone as most of it is AC3 5.1 (beyond my phone’s bag of tricks).
Getting all (most) of your stuff to Direct Play doesn’t happen without varying degrees of manual user intervention. How often Direct Play is achieved relates directly to how much you intervene manually before you stick it in a library.
Sure. AAC is also standard for Apple music and its 20+ million subscribers, and the default Youtube format. I thought those were pretty common sources.
The situation still bugs me because Amazon lists AAC 6 channel support on the Fire Stick, so even if it can’t passthrough 5.1, as MovieFan.Plex says, then I should be able to disable passthrough and decode it locally. I guess there’s something that I’m not understanding.
Not really an issue. I’m going to let it transcode, as it’s not that often. Just really odd - especially since I have a non-4k Fire Stick as well and it direct plays AAC without issue.
Well, there you go.
Is Plex fumbling the handling of your AAC 5.1? I don’t know, or care, but it does misbehave more often than not across the devices likely to encounter my Plexiverse and if it won’t Direct Play there’s either something wonky with the format or with the way Plex is handling it. I know what the material has to be in order to Direct Play, so that happens before it’s added. Takes a few minutes. Worth it in the long run when I never have to deal with it again.
There are some things that realistically need to be done before material is added to a Plex Library if you want it to behave. If you don’t do those things and your material misbehaves fixing it yourself is way quicker than waiting for Plex to fix it.
Yes, it should. But decoding is not the same as pas through. As I said, the Fire TVs cannot passthrough aac 5.1 so it will decode locally to stereo and that is what gets sent to your receiver. Is this not what happens for you if you turn it off?
I have same issue. Fire tv stick 4k always transcode with aac audio to ac3. Video is always transcode mp4 to mpegts. I really crazy with this. For all other devices, it can direct play even fire stick non-4k.
The same movie with aac 5.1 h264, it can direct play on non-4k fire stick but always transcode on 4k fire stick.
Same problem with a Firestick 4K . Prefer Plex but had to install Emby on the Firestick 4K too. Emby handles AAC 5.1 just fine without me doing anything special. Emby has other problems so I switch abit back and forth depending on the movie 
It doesn’t for me. I turned off Passthrough and tried playing back a program. Plex still saying it’s transcoding because the FireTV Stick 4K “does not support AAC audio”.
Can you get me the app log?
Since it’s FireTV I assume you mean the network logging? I rebooted the Fire Stick and reinstalled the Plex app to clear old data out from the logs. Once it was re-linked up with my account I confirmed Passthrough was off and tried playing several files that have 5.1 AAC audio. All of them transcoded.
Did you by chance edit your Android profile in PMS?
