I’ve been reading through the various threads on plex/atv 4k playing lossy atmos. I’ve got a file that has EAC3 5.1 w/ DDP. However, when playing it, my Denon shows it as PCM.
I expected it to show up as Atmos on the receiver - which is how it shows up when playing Netflix via the ATV. I checked the transcoding and it looks like it is getting sent over directly. Has anyone gotten plex and ATV to play dolby digital plus via EAC3?
I think I once heard only special apps with special partnership to Apple have access to the Atmos API. So this may be correct.
You should be able to passthrough EAC3 / Dolby Digital Plus audio irrespective of Atmos.
When you play a video in Plex with AC3 / Dolby Digital does it passthrough to your Denon or does it show up as PCM as well?
Double check both AppleTV settings and Plex app settings for anything that affects passthrough audio.
Try turning off the subtitles.
Try the Leaf and Amaze trailers from Dolby. They’re mp4 files, so they should direct play vs direct stream (which should not matter). Download the trailers (right click, save-as) and put them in an “Other Videos” library, so Plex won’t try to match them as movies or tv shows.
FYI, EAC3 and Dolby Digital Plus are the same thing (Wikipedia). Atmos is additional metadata added to the audio stream (Wikipedia).
Thanks a ton for chiming in!
Two things - the two atmos files worked perfectly. Secondly, turning off the subtitles made the original movie work too!
I appreciate the background on EAC3/DDP/Atmos. Curious - what’s the difference in audio format for the two files? From plex, they look similar. Below is what I see for the Leaf demo. I’m curious why one shows up as Multi In + DDS while the other shows as Atmos on the receiver.
There is no difference between the two Dolby trailers. They should both direct play and show up as Atmos on your receiver.
In addition to the front panel display you can also press the INFO button on your remote. It should pull up the On Screen Display, showing what audio format the Denon is receiving (Works on my Denon AVR-X4300).
As for why subtitles affected your first video, I’m not sure. I don’t have an Apple TV. It was just a hunch. Subtitles are known troublemakers in Plexlandia. They sometimes have undesired consequences.
Direct Streaming is just Plex Server repackaging the streams to another container. It should not affect the streams themselves. SRT subtitles generally direct play when the audio and video direct play or direct stream. There’s probably an interaction between direct streaming and subtitles of which I’m unaware.
Maybe an AppleTV owner can weigh in with more details.
I was asking what the difference was between the movie I was playing and the atmos demo trailers. The Atmos demo trailers show up as Atmos on the receiver while the movie showed up as Multi In + DDS.
I’m basically trying to understand the limit of what plex + atv can play. I know it can’t do TrueHD w/ atmos. I thought the limit was Dolby Digital Plus, but the atmos demos make me think I don’t understand exactly where that limit is. From your wikipedia posts - are the two demo videos just dolby digital plus with atmos?
Yes.
Unfortunately, Plex does not indicate when an audio track has Atmos. It only shows EAC3 or TrueHD.
You can examine the files using MediaInfo.
For EAC3 + Atmos you will see something like:
Audio
ID : 2
Format : E-AC-3 JOC
Format/Info : Enhanced AC-3 with Joint Object Coding
Commercial name : Dolby Digital Plus with Dolby Atmos
Codec ID : ec-3
Understand.
AC3, EAC3, and EAC3 + Atmos should direct play and be passed to your Denon receiver.
However, as you’ve seen, subtitles come into play and can cause an audio or video transcode. When the audio is transcoded, any Atmos information is lost.
The part I cannot tell you is how subtitles affect things, as I’ve no way to test that myself.
Hopefully somebody with an ATV4K can chime in with additional information.
Chiming back in on this. After more googling, I bought a Nvidia Shield and things work out of the box. Amazing how much better it is for plex than the Apple TV. Turned on passthrough and haven’t been able to find a format that didn’t work.
Just thought I’d mention in case anyone else saw this. Disappointing that apple isn’t prioritizing high quality sound formats/systems.
Exact same reason I ditched my Apple TV. Nvidia Shield is light year ahead.
Apple is behind in supporting audio codecs. I suspect they aren’t interested in any high bitrate/lossless audio as that would limit their customer base as the ATV is a TV connected iTunes storefront.
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.
