Plex on Samsung TV supports and direct play EAC3 audio but Roku transcode it

roku

#1

I have a Samsung Smart TV that can direct play EAC3 on the Plex application but when the same audio is played on my Roku Express, it is transcoding the audio (sometimes together with the video).

Plex TV Configuration: Direct Play: Auto
Roku Configuration:
Audio Setting: (Dolby Digital +, DTS), Auto: Surround
Plex Configuration: Direct Play: Auto (when Force, there is no audio)

Samsung TV can direct play the EAC3 even when using only an optical cable to the receiver. Roku Express is connected via HDMI to the TV and optical cable to the receiver (my receiver doesn't have an HDMI input).

My question is if TV supports and direct play EAC3 audio then Roku Express should also be able to direct play or passthrough EAC3, right?


#2

@“ECO - TV”
EAC3 is “Dolby Digital Plus”. Many think EAC3 is “TrueHD”. According to https://support.roku.com/article/208754908-how-to-use-roku-media-player-to-play-your-videos-music-and-photos , TrueHD is not supported on any Roku. According to another site, only the Ultra will decode certain Dolby formats down to a capability of your receiver.

Are you positive you are not confusing TrueHD for EAC3?

I’d recommend attaching the XML of one of your videos that aren’t working as expected to your next reply post.
It will contain information we may be able to use to tell why it’s not direct playing for you.
(Don’t just paste it in, you can drag and drop into your post to attach it)


#3

@JamminR said:
@“ECO - TV”
EAC3 is “Dolby Digital Plus”. Many think EAC3 is “TrueHD”. According to https://support.roku.com/article/208754908-how-to-use-roku-media-player-to-play-your-videos-music-and-photos , TrueHD is not supported on any Roku. According to another site, only the Ultra will decode certain Dolby formats down to a capability of your receiver.

Are you positive you are not confusing TrueHD for EAC3?

I’d recommend attaching the XML of one of your videos that aren’t working as expected to your next reply post.
It will contain information we may be able to use to tell why it’s not direct playing for you.
(Don’t just paste it in, you can drag and drop into your post to attach it)

Yes. I mediainfo everything and I know what TrueHD is. I am positive that it is an EAC3.


#4

Please use the XML from Plex so we may verify that Plex is seeing what MediaInfo sees. (It’s possible it’s not analyzing right.)


#5

Oh, also, I just re-examined your first post.
You have Roku HDMI out to TV, then TV optical out to receiver?
That may be part of the issue. Your Roku has ‘DD+ and DTS’ shown in your first post, did you set that, or did Roku Express choose those? It’s possible the TV might not be capable of pass-through like the actual Roku is, and could be converting it.
I’d also check TV settings to see if it has a passthrough enable from the HDMI input your Roku is connected ot.


#6

@JamminR said:
Oh, also, I just re-examined your first post.
You have Roku HDMI out to TV, then TV optical out to receiver?
That may be part of the issue. Your Roku has ‘DD+ and DTS’ shown in your first post, did you set that, or did Roku Express choose those? It’s possible the TV might not be capable of pass-through like the actual Roku is, and could be converting it.
I’d also check TV settings to see if it has a passthrough enable from the HDMI input your Roku is connected ot.

Would that not be correct? Does Roku not passthrough the EAC3 audio to TV and let the TV decode it before going to the optical cable?

Attached is a txt file from the mediainfo.


#7

@“ECO - TV” said:
let the TV decode it before going to the optical cable?

That’s the issue. I think your TV is forcing stereo on the EAC3 passed from Roku.
My theory - Roku is passing EAC3 across the HDMI. TV sees it. Chews it up. Spits out stereo to the receiver.
Is your Samsung TV connected to the same receiver?? Using Optical? And you say it plays 5.1 on it?
According to this article, https://www.lifewire.com/digital-optical-connection-1846881
optical can’t carry EAC3 (or any AC3 5.1 it seems).

The types of digital audio signals that can be transferred by a digital optical connection include two-channel stereo PCM, Dolby Digital/Dolby Digital EX, DTS Digital Surround, and DTS ES.

It is important to note that digital audio signals, such as 5.1/7.1 multi-channel PCM, Dolby Digital Plus, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, DTS:X, and Auro 3D Audio cannot be transferred via Digital Optical connections - These formats require HDMI connections.


#8

Yes. The TV is connected to the receiver.

As I said on my first post: TV can decode EAC3 or AC3 if played directly using the Plex app on the TV itself, yes, Plex will direct play them. TV will then send the 5.1 audio to the receiver. Roku doesn’t do that. It feels like Roku just see the TV as a stereo or something that it think can’t decode.


#9

@“ECO - TV” - Can Netflix/Amazon/other streaming services that offer high quality encoded content play 5.1 DD+ from the Roku to the TV to the Receiver ?
The “TV supports” may mean it will take any AC3 / EAC3 signal and convert it to stereo. There are many soundbar discussions on the internet where people ask this same thing, something they are feeding the TV is converted to stereo, even on a surround capable soundbar.
Have you checked the TV settings to ensure there isn’t a passthrough option?