No HDR/Atmos when there is no reason not to

Server: Ryzen based Win10 Pro >> Gbit (CAT5E) to nVidia Shield, connected to HDMI IN of LG SL8Y, then ARC to Sony X90F

Hi guys, I have bought a new 5.1 soundbar combo and can’t for the life of me figure out why things don’t work out.
Soundbar supports HDR10/Vision/Atmos/DTS-X, and yet Plex transcodes 4k HDR movies. It just stutters and freezes like crazy and on the server’s webpage I can see that it’s transcoding both video and audio. Sometimes it doesn’t even load the video and just shows an error status.

The server is set to feed everything on the highest quality.

Any ideas what can cause this?

I take it the soundbar supports the format, but it’s too much for the ARC channel (unless it’s actually eARC).

The TV does not support eARC, so there was no need for me to buy a soundbar that has it.

Is there possibly a setting in the Shields Plex client where something can make things ■■■■■■ I havent found anything besides None/HDMI/Optical in Sound settings.

Without eARC support for Dolby Atmos is limited. Dolby Atmos can be passed over regular ARC (via Dolby Digital Plus) eARC is required for higher-quality Dolby TrueHD and DTS-HD Master Audio streams, including Atmos.

That I understand, but that shouldn’t force Plex to transcode video as well (I think).

Can you please post a screenshot of the Now Playing (expanded) section in the server Dashboard via the web browser during playback?

Screen Shot 2020-04-14 at 8.21.25 AM

Suggestion: Simplify the testing process.

Take the soundbar out of the loop.

Connect the Shield directly to the TV.

Play a 4K HDR movie with an AC3/DD 5.1 soundtrack and subtitles disabled.

That should direct play for both the audio and video. If it does not, diagnose and correct the issue.

Once that setup is working OK, put the soundbar back in place.

Repeat test with same movie, AC3 audio track, and no subtitles.

If it does not direct play, then diagnose and correct.

Once that is direct playing, try with Dolby Atmos and other audio formats.

Note 1: Leaving subtitles off is important for testing. With AndroidTV devices, if the audio is transcoding and subtitles are enabled, then the video also transcodes. Once you have media direct playing w/o subtitles, you can then try with subtitles. Best to minimize the number of variables.

Note 2: With the Shield connected to the soundbar, the ARC/eARC discussion is irrelevant. The audio goes from the Shield to the soundbar and stops. The ARC channel between the TV & soundbar is never used.

plex

Turn off subtitles.

Choose an AC3 or dts audio track if possible.

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Uhm, seems like subtitles are the problem. But since my household is not speaking English very well (or not at all) this is tragic. Is there a way to make this work guys?

What happens with subtitles disabled?

What direct plays / what transcodes?

In current versions of the Android TV app, audio transcode + subtitles = video transcode.

This is supposedly being fixed in an upcoming beta release, but it has yet to ship, so unknown if it really works.

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I have selected AC3/DTS 5.1 audio and Plex stopped transcoding the audio. Still transcoded the video though. I turned off subs, and movie stopped stuttering (havent checked Plex status).

So, with AC3 audio and no subtitles the audio direct plays.

Now to figure out why the video is still transcoding.

Start by reviewing the video settings for the Shield itself (not the Plex app).

Make sure the Shield is set for 4K video and BT2020 colorspace.

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Checked, it is set on 4k, 59,940, YUV 420, BT2020.

That looks OK. I’ve same on my Shield.

Check Plex app on Shield.
In Video Quality Section
Adjust Automatically = Off
Home Streaming = Maximum

Not sure if there are any applicable soundbar or tv settings, but check those as well.

If the video is still transcoding, then you’ll probably have to pull log files from PMS and the Shield to see what is happening. Set your Plex server for Debug logs only. Enable logging in the Shield Plex app. Play the movie for 15 - 20 seconds (ac3/dts audio, no subtitles). Stop playing. Pull logs and attach to thread. See articles below for additional details on pulling logs.

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Thank you, I really really appreciate your help. I will get to it once I will have time, and come back to report.

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