Audio transcoding when not needed?

Server Version#: 1.32.3.7162
Player Version#: 5.61.0

I got a 2021 Samsung TV and I know this only Supports AAC as audio codec.
I just bougt a new Soundbar supporting a wide range of codecs including DTS (most varians) AC3 and so on.
When I select a video which is not AAC it gets transcoded to ACC. I wonder why is that ?

In the playback infromation it tells me: “Cannot direct play with protocol: http, codec dca. Reason: Codec dca is excluded per setting DTS:false”
“Cannot direct play with protocol: http, codec dca. Reason: Player does not support selecting alternative audio stream”
or
“Cannot direct play with protocol: http, codec ac3. Reason: Player does not support selecting alternative audio stream”

the logs show this (just an example)

and so on. I wonder why this is ? I really thought that with the new soundbar there was no trancoding needed ?

Any help is much appreciated

Look in the settings of the Plex app on your TV.
Make sure that “pass-through” for audio is activated.

It means that Plex thinks that your TV is not capable of decoding DTS audio.
Which is true for many TV devices made in a certain time period. These devices weren’t even able to “pass-through” the undecoded audio stream to an attached sound bar or AVR.
So the ability of your sound bar won’t help you overcome the limitation of your TV.

The only way is to either

  • let the server transcode the audio
  • use a different player device (e.g. an Nvidia Shield Pro) and wire it first to your sound bar, then go from the sound bar to the TV. (Both connections with HDMI). If your sound bar doesn’t have a HDMI output, it is unfortunately not usable for you.

Looks like the Samsung App does not have that setting ? Can´t find that anywhere.

Will check with Samsung support if there is an option to pass through. I found one setting for pass trough, but this is only for incoming HDMI to E-ARC passthrough. So I would need an external player, which defeats the idea of the Apps on the TV.

Samsung dropped support for DTS audio in 2018. They have never supported TrueHD audio. This includes passthrough from TV based apps. Plex Media Server will transcode both to a supported format.

Passthrough for HDMI attached devices may differ from that for TV based apps. See if rtings.com has reviewed your TV (and the review is not behind their paywall). They test audio passthrough for HDMI attached devices.

Thanks, I was hoping that it works for the Apps with Soundbar attached. Time for a new TV then :S

Many TVs have similar restrictions. Check the manufacturer web sites and also review sites before purchasing.

Note that no TV on the market today will passthrough TrueHD audio from a TV based app, and some block it for HDMI attached devices.

Thanks @FordGuy61 , I just checked the AppleTV+ App on my TV and selected an Dolby Athmos title. The Soundbar was indicating a Dolby Atmos audio stream… now I’m puzzled.

There are two forms of Dolby Atmos for home theaters: TrueHD + Atmos and Dolby Digital Plus + Atmos.

TrueHD + Atmos is the type found on Blu-ray discs. As mentioned above, it is not supported by TV based apps and will be transcoded by Plex Media Server, with Atmos info lost in the process.

Dolby Digital Plus + Atmos is the type used by streaming services such as Apple, Netflix, etc. Dolby Digital Plus can be passed over HDMI from TV based apps and HDMI attached devices. Pretty much every Smart TV on the market supports this.

The Plex app on your TV should pass DDP+Atmos as well.

Download the second file, Channel ID 5.1 Atmos with H.264, from DOLBY DIGITAL PLUS Online Delivery Kit and place it in a Other Videos library on your server. If everything is correctly configured, it should direct play and light up the Dolby Atmos indicator on your soundbar.

Thanks @FordGuy61 , will do and let you know

Ha, yeah this works as you described it. It indicates Dolby Atmos.

Thanks for the clarification.

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