PLEX audio dropouts and sync issues with seamless branching on 4K TrueHD/Atmos movies

They (your parents) have an nvidia Shield?

Yep, exact same model. SHIELD TV pro.

I didn’t have any issues with Dominion.

I have to go through my sound bar for DTS-HD/DTS:X to work. I also needed to upgrade to two certified 8k (48Gbps) HDMI cables, otherwise I’d have occasional issues with DoVi + HD audio. I previously had one 4k and one 8k.

Just tried to watch Wrath of Khan 4K DE today that I ripped last year from the 4K boxset, the out of synch sound issue was so bad that an hourish in to the film I put the disc in the player and watched it that way.

Whenever the issue occurred if I stopped playback and then resumed the audio sync would correct itself, but at the next branching point you would get a slight audio dropout and then you could see audio sync would get lost, by quite a margin as well. If you skip back to prior to the point the issue occurred the issue will manifest itself again.

I am using a Nvidia Shield 2019, I did try Kodi afterwards and tried the scene I first noticed it on and it played absolutely perfectly.

Now that you mention that I was reading a review of how good the 4K upgrade of original Star Trek - The Motion Picture was - they re-rendered previous SD resolution FX work in 4K even for it but then it mentioned that there was Directors Cut and Extended Cuts and seamless branching was used and I was thinking oh no, here we go… won’t be able to put that on PLEX now either!

Still having audio issues, can only imagine this format will continue to grow in popularity as time goes on

Sadly, the bug submission for Google’s exoplayer (which seems to be the culprit here) hasn’t been touched since it was acknowledged by the exoplayer team.

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Sadly, ExoPlayer/AndroidX Media development has been incredibly slow, and the list of issues keeps growing every day.

One thing of note is that Plex is currently still on 2.18.0. I pinged one of the Android devs in another thread about updating to the latest release this morning.

Hey all. I m not sure it is right topic to write if not please excuse me as I am new here. I am having the buffering problem with 7.1TRUEHD videos. when I try to watch any videos with Truehd its buffering endlessly. I have no problem with other formats so far like DTS 5.1 or dolby digital 5.1 its only with atmos / truehd7.1
I am using MI STICK 4K device by the way.

Not really right place no - you basically need to look at the info option in the player menu while your stuttering video is playing and see if it says TRANSCODING or DIRECT PLAY. It should be doing direct play. If it is transcoding it means what ever machine the video is on is doing the conversion in real time while playing and is too slow to do it.

Thank you for information. It says direct play

Having this exact same issue with direct play videos played via NAS to my NVIDIA Shield Pro 2019 using Plex.

Only seems to have started happening recently, and happens with regular frequency on different video source files - most recently on 2 videos with Dolby TrueHD 7.1 tracks on them.

There will be a momentary break in audio, and then desync between the video and audio. Pausing and resuming fixes the sync usually, but rewinding to the point where the break happens and resuming playback will cause the desync to happen every single time at the same point in the video without fail.

Out of interest, which two movies did you find it happening on? Are they from Bluray source?

Both had really high quality audio tracks unchanged from their sources - 7.1 TrueHD / ATMOS.

Neither were “streaming” tier quality.

Yes, but what is name of the two movies? If they are mainstream Hollywood type movies then we also might have them and can check the discs at same place you found sound dropout and add to list of problem movies.

I forget the name of one, but one was definitely Martian extended cut

ExoPlayer 2.18.2 was released a few days ago. See here for more info: Releases · google/ExoPlayer · GitHub

Didn’t see anything related to the seamless branching issue discussed here, but it certainly wouldn’t hurt to update. Plex for Android is now two versions behind.

The Martian Extended Cut is well known for the described issue with seamless branching.

The other one would be very interesting though, because this issue here only affects TrueHD, so you should NOT be able to see problems with DTS soundtracks.

Might not have been a DTS track. Edited previous comment.

Sorry it was from a few days back so I might be misremembering. Might be from 2 different versions of the Martian I tried.

You are right - it was Martian extended listening with TRUEHD. This is also happening in Directors cut of Fast & Furious 9 with TRUEHD and The Natural extended cut with TrueHD.