Converting to a lower quality fails with Hardware-Accelerated Streaming in Plex Web

Plex Media Server
,
105

@ChuckPa,

I still reproduce this problem on 100% bare metal.

  • Android app can request transcodes fine
  • Roku transcodes fine
  • SyncLounge (html / web based) transcodes fine
  • Plex Web consistently does not transcode

Here is my /dev/dri

ls -al /dev/dri/
total 0
drwxr-xr-x  3 root root       100 Apr 26 16:57 .
drwxr-xr-x 22 root root      4320 Apr 27 16:02 ..
drwxr-xr-x  2 root root        80 Apr 26 16:57 by-path
crw-rw----  1 root video 226,   0 Apr 27 15:48 card0

Here is my install log for the latest version:

Unpacking plexmediaserver (1.22.2.4282-a97b03fad) over (1.22.2.4264-b275c4330) ...
Setting up plexmediaserver (1.22.2.4282-a97b03fad) ...
PlexMediaServer install: PlexMediaServer-1.22.2.4282-a97b03fad - Installation starting.
PlexMediaServer install:
PlexMediaServer install: Now installing based on:
PlexMediaServer install:   Installation Type:   Update
PlexMediaServer install:   Process Control:     systemd
PlexMediaServer install:   Plex User:           plex
PlexMediaServer install:   Plex Group:          plex
PlexMediaServer install:   Video Group:         video
PlexMediaServer install:   Metadata Dir:        /var/lib/plexmediaserver/Library/Application Support
PlexMediaServer install:   Temp Directory:      /dev/shm  (set in Preferences.xml)
PlexMediaServer install:   Lang Encoding:       en_US.UTF-8
PlexMediaServer install:   Intel QSV Hardware:  Not found
PlexMediaServer install:   Nvidia GPU card:     Found
PlexMediaServer install:
PlexMediaServer install:   OpenCL library:      Installed
PlexMediaServer install:   Beignet package:     Installed
PlexMediaServer install:
PlexMediaServer install: Completing final configuration.
PlexMediaServer install: Starting Plex Media Server.
PlexMediaServer install: PlexMediaServer-1.22.2.4282-a97b03fad - Installation successful.  Errors: 0, Warnings: 0
Processing triggers for libc-bin (2.31-0ubuntu9.2) ...
Processing triggers for mime-support (3.64ubuntu1) ...

Latest ubuntu:

grep DISTRIB_DESCRIPTION /etc/*release
/etc/lsb-release:DISTRIB_DESCRIPTION="Ubuntu 20.04.2 LTS"

Latest supported kernel:
Linux nas 5.8.0-50-generic #56~20.04.1-Ubuntu SMP Mon Apr 12 21:46:35 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

Latest Nvidia Production Branch Release

cat /proc/driver/nvidia/version
NVRM version: NVIDIA UNIX x86_64 Kernel Module  460.73.01  Thu Apr  1 21:40:36 UTC 2021
GCC version:  gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)

Log snippet, derived with the following steps

  1. cleared with truncate -s 0 *.log
  2. click play at original quality
  3. switch to 480p

Results

  1. plex web plays original quality
  2. once switched, log full of ffmpeg flags with transcoder capabilities
  3. plex kills transcoder 3-5 times
    • nvidia-smi show gpu process for a moment, then it dies, repeat for each kill
  4. transcoded video never (or very rarely) plays

I can reproduce this problem on any media in my library, but I specifically test on Blender Foundation’s Sintel as it is creative commons and can be redistributed anywhere.

logs.zip (16.6 KB)