Issue with UHD+HDR+HEVC on Plex Web and Plex Android

Plex Players
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1

Server Version#: 1.43.1.10611 (Raspberry Pi)
Player Version#: 2026.8.1

Hello everyone,

I record videos on my Samsung S26U in UHD, 30fps, HDR, and HEVC. The Plex app on Android (Samsung S26U) freezes after about 4 seconds of playback. On the Plex server, however, it appears that the video continues to stream via Direct Play all the way to the end.

The Plex Web Player (Chrome, Windows 11) remains black from the beginning. Plex server tries to transcode and fails evidently during the process.

The playback via the Plex app on WebOS (LG TV) works without any issues!

Is this a known issue? Are there any suggestions on how to resolve it?

Best regards

2

Try opening a sample file in https://mediaarea.net/en/MediaInfo and post the txt content here for one of the source files you’re having issues with.

Might be something the meta data reveals that could explain the issue.

3

here is the output

General
Complete name : xxxx.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
File size : 321 MiB
Duration : 58 s 467 ms
Overall bit rate : 46.0 Mb/s
Frame rate : 30.000 FPS
Encoded date : 2026-04-29 16:00:55 UTC
Tagged date : 2026-04-29 16:00:55 UTC
Writing operating system : Google Android 16
Writing hardware : Samsung SM-S948B
com.samsung.android.utc_offset : +0200

Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5.2@Main
Codec ID : hvc1
Codec ID/Info : High Efficiency Video Coding
Duration : 58 s 467 ms
Source duration : 58 s 433 ms
Bit rate : 44.0 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.177
Stream size : 307 MiB (96%)
Source stream size : 320 MiB (100%)
Title : VideoHandle
Language : English
Encoded date : 2026-04-29 16:00:55 UTC
Tagged date : 2026-04-29 16:00:55 UTC
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : HLG
Matrix coefficients : BT.2020 non-constant
mdhd_Duration : 58467
Codec configuration box : hvcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 58 s 431 ms
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 913 KiB (0%)
Title : SoundHandle
Language : English
Encoded date : 2026-04-29 16:00:55 UTC
Tagged date : 2026-04-29 16:00:55 UTC

4

The format profile stuck out to me. So, I checked it against a couple of blue ray rips.

Standard 24fps
Main 10@L5@High

Gemini man 60FPS bluray
Format profile Main 10@L5.1@High

Your phone is using Main 10@L5.2@Main

Did a quick search, I’d beat the issue has to do with GPU support on the playback device.

Key Technical Breakdowns

  • Level 5.2 vs. Level 5 (Processing Load): The level determines the maximum processing speed (luma sample rate). Level 5.2 processes up to 1,069,547,520 samples per second, enabling fluid 4K video at 120 frames per second. Level 5 maxes out at 267,386,880 samples per second, restricting 4K video to a maximum of 30 frames per second.

  • Main Tier vs. High Tier (Bandwidth Cap): Tiers dictate the ceiling for the video data stream. The High Tier allows for a significantly thicker data pipeline (100 Mbps vs 60 Mbps), ensuring fewer compression artifacts in complex, fast-moving scenes at the expense of storage size.

:globe_with_meridians: Browser & Hardware Playback Impact

  • Decoder Compatibility: Hardware decoders inside your graphics card or CPU are built to strict Level and Tier thresholds. A decoder rated only for Level 5.1 will drop frames or fail entirely when attempting to process a Level 5.2 stream.

  • Hardware Acceleration: Windows 11 and Google Chrome lean heavily on GPU hardware acceleration for 10-bit playback. While almost all modern systems easily accelerate Main Tier profiles, files explicitly tagged as High Tier can occasionally trip up consumer hardware decoders, forcing Chrome to fall back to software decoding, causing high CPU spikes and stuttering

No. Plex Media Server’s internal FFmpeg-based transcoder cannot transcode a video into an HEVC file targeting a specific profile level and tier like Main 10 @ Level 5 @ High Tier

Here is exactly why, how Plex handles it, and how you can do it yourself using standalone FFmpeg.

:prohibited: Why Plex Cannot Do This

  1. Target Codec Limit: By default, the Plex Media Server transcoder converts almost all video streams into H.264 (AVC), not HEVC (H.265). While Plex has experimental support to transcode into HEVC under specific conditions (using select Intel/NVIDIA hardware and a Plex Pass), it acts as a closed, automated system.

  2. No Advanced Parameter Controls: Plex’s automated pipelines do not allow you to manually inject specialized internal encoder flags (like changing a container’s explicit tier or level profile markers)

That said, it is weird that the same phone can play the file back, suggests it could also be a gap with the android app supporting that profile.

What happens if you try to play the file directly on the Win11 machine instead of within a browser?

5

the issue accures allso with level 5 (not only 5.2) sources. for some reason samsung produce both levels.

on same devices, Win 11 notebook or Smartphone there is no issue by using another player such as windows media player or vcl or google photos app. There should be no hardware restrictions this way.

WebOs-Version of the plex app works normally. It indicates a software cause for other plex app versions.

regarding transcoding . Plex shoud transcode into the h.264, not vice versa (unstable, experimental)

Update: Plex App for windows fails the same way. Plex server shows direct play with freezed buffering. My Notebook is a new lenovo with i7 CPU inside. Like I wrote other players on the notebook make no trouble with the same videos.

Same behavior for following format:

Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/mp42)
File size : 929 MiB
Duration : 6 min 6 s
Overall bit rate : 21.3 Mb/s
Frame rate : 30.000 FPS
Encoded date : 2026-05-10 17:09:52 UTC
Tagged date : 2026-05-10 17:09:52 UTC
Writing operating system : Google Android 16
Writing hardware : Samsung SM-S948B
com.samsung.android.utc_offset : +0200

Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main 10@L5@Main
Codec ID : hvc1
Codec ID/Info : High Efficiency Video Coding
Duration : 6 min 6 s
Source duration : 6 min 6 s
Bit rate : 21.1 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 30.000 FPS
Minimum frame rate : 30.000 FPS
Maximum frame rate : 30.010 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.340
Stream size : 924 MiB (99%)
Source stream size : 924 MiB (99%)
Title : VideoHandle
Language : English
Encoded date : 2026-05-10 17:09:52 UTC
Tagged date : 2026-05-10 17:09:52 UTC
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : HLG
Matrix coefficients : BT.2020 non-constant
mdhd_Duration : 366633
Codec configuration box : hvcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 6 min 6 s
Bit rate mode : Constant
Bit rate : 128 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 5.59 MiB (1%)
Title : SoundHandle
Language : English
Encoded date : 2026-05-10 17:09:52 UTC
Tagged date : 2026-05-10 17:09:52 UT

6

I just saw the server is (Raspberry Pi)? Specs?

Pretty sure the 4k transcode fail on windows is because of that. Any 4K transcode is going to need a capable GPU are a 12-16 cpu cores.

I imagine when you use the phone it’s over wifi, what about WebOS is that connected over wifi?
Same network?

is the pi connected via wifi?

are all these devices running off of one access point?

this could be a network issue

7

You are on the wrong track. All the facts presented point against server or network issues. With Direct Play running, no transcoding or cpu loading issues could and are accure. I can see it in monitoring. I have a very strong network far above required bandwith.

My current suspicion is that the Plex players on Android and the web are unable to handle very high bitrates—ranging from 90 Mbps up to 250 Mbps with HEVC. Unlike VLC, with its own highly efficient decoder, or the hardware-optimized version of the Plex app on webOS. webOS is optimized to handle high bandwith due to blue ray and hdmi storage input.

8

If everything is connected via wifi and only running off of one AP or two… it could be network. Even if it’s WiFi 7

The web players can’t handle high bit rates at all. All my videos are blue ray rips and I have to use the desktop app. Even with my Roku, there are some videos that bitrates overwhelm the GPU which look like sparkle or corruption. But I check the file and playback on a computer without issue.

I don’t know how those apps are designed, I never use them but if they took shortcuts and designed them like the app client that could be the case.