Server Version#: 1.13.8.5395
Player Version#: Plex for Samsung 3.3.4
Server Hardware: 12 vCPU Xeon 3Ghz on VMware 6.7, Windows Server 2016 x64, 64GB vRAM, 40TB SAS RAID local storage array, 10gbit LAN
TV: Samsung 75" Q8FN
When attempting to play ripped UHD 4K movies from Plex I get constant stuttering. The TV – quite stupidly IMO – can’t decode (or even pass through to my receiver) TrueHD or DTS-HD MA. It will play native HEVC 10-bit content so the only thing it should transcode is the audio. The TV can natively play DD 5.1 streams however.
Checking Plex Server status during playback it shows the video as “Direct” and the audio as “transcode to AAC”. However, it apparently can’t keep up with transcoding the audio in real time despite having TWELVE 3GHz Xeon vCPU’s at its disposal. I find this to be bizarre. I can’t imagine audio transcoding could saturate all those CPU’s. Further I don’t NEED it to transcode to AAC when PCM or DD would be fine. Yet there isn’t an option on Plex to specify audio transcode formats and the Samsung Plex app also lacks any options. It only allows me to enable/disable TrueHD and DTS-HD support (both are disabled since the TV doesn’t support them). Leaving them enabled gives me stutter-free video but no audio which leads me to suspect the audio transcoding as the culprit.
Can someone give me some guidance on this issue? I suspect there’s more going on than just audio transcoding and that’s what’s saturating the server CPU’s. 4K is obviously very demanding if it’s transcoded but it shouldn’t BE messing with the video; it should be transcoding nothing but the audio.
its probably not the audio transcoding itself, its the total bitrate/throughput that your vm/server must be able to sustain.
since the video bitrate isn’t changing, your server has to read the original stream, transcode the audio, remux that high bitrate video with the audio, and send it out to the tv.
I would suggest looking at the IO bottlenecks.
you really want to direct stream 4k, I would also suggest looking at getting an nvidia shield that can direct play the audio streams, and a receiver that can decode them (not sending the audio through the tv, but through the receiver first).
Aha…I didn’t consider it had to remux the stream after transcoding. That’s very likely the issue. However, as you can see from my original post, my server is pretty beefy. It’s running dual hyperthreaded hex-core Xeon’s at 3GHz on a Dell R620 with 128GB of RAM (64GB dedicated to the server VM). I’ve got 10gbit networking and a 40TB SAS RAID array with a separate 1TB flash array for temp storage. I/O throughput shouldn’t be a problem for a single stream but perhaps I’m underestimating how hard 4K is pushing it.
Oh also, I forgot to mention I just purchased a new Marantz receiver, just arrived today. My prior receiver wouldn’t handle 4:4:4 HEVC 10-bit HDR 4K @ 60Hz so I needed an upgrade. It’s handling it fine now being fed by my Vero 4K+ media player, but I still wondered why the Samsung Plex app was choking just in case I ever need to revert to it.
Pretty much any current TV’s only support 5.1 or lossy 7.1 dd.
So for smart tvs with the apps built in, when they stream and send the audio back out the hdmi (ARC) or optical (only 5.1).
When HDMI 2.1 devices start getting released, they should have an upgrade ARC called E-ARC which supports passing back atmos and other lossless surround audio formats.
Yeah I was using ARC for my setup but it was almost useless. The big shock to me is the Samsung won’t pass the raw bitstream through ANY interface. Not ARC, not optical…nothing. That was a big, unpleasant surprise. I figured if it couldn’t decode it, it would at least PASS it but nope .
Yeah my current setup is Vero4K+ -> Marantz AVR -> Samsung Q8FN. Just a pity the app is basically useless for lossless audio. eARC may be nice but I guess it’s a moot point now.
After fooling around with a lot of other hardware I settled on the Vero 4K+. It’s one of the few devices that supports 4:4:4 HEVC HDR 10-bit 4K @ 60Hz. It resembles a Raspberry Pi but on steroids, running Kodi with Plex for Kodi as the Plex player front-end.
So far I highly recommend the device. I haven’t had a Shield to compare it to but from what I could see this is the most feature-complete HDR-ready device out there that’ll work with Plex. I tried the following before settling on the Vero:
Raspberry Pi - no 4k, no HDR (before I got 4K TV)
ODroid C2 - no 4k, no HDR (ditto)
Rockchip PINE64 - 4k, no HDR (software limitation apparently, may be fixed in the future)
Vero 4K+ - 4k, HDR, 10-bit HEVC…all the goodies!
how did you workaround the vero stuttering playback?
I have a similar setup (plex 8-core server > vero4k+kodi > marantz > TV)
while audio syncing is not an issue for me, I have stuttering playback on the vero 4k unless I force transcode. Any tips/hints? it’s offtopic by now, right?
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