[BUG] HW transcoding issues with 1.43.0

[CaptainPimpJr]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

When PMS tries to transcode AC3, following error is shown in PMS logs and the file won't start:
Cannot write moov atom before AC3 packets. Set the delay_moov flag to fix this.
I have downgraded to 1.42.2 and playing the file works without an issue.
Plex runs on a system with i3-9100 and UHD 630 graphics.

Expected Behavior

Transcoding AC3 should run flawlessly. See 1.42.2.

Steps To Reproduce

1. Docker to latest. Tested with 1.43.0.
2. Run a file with AC3 encoding.
3. File is not running.

Environment

- OS:unraid 7.2.3
- How docker service was installed: via Community Apps set to latest

CPU architecture

x86-64

Docker creation

/usr/local/emhttp/plugins/dynamix.docker.manager/scripts/docker create --name='plex' --net='host' --pids-limit 2048 -e TZ="Europe/Berlin" -e HOST_OS="Unraid" -e HOST_HOSTNAME="FujiTower" -e HOST_CONTAINERNAME="plex" -e 'VERSION'='docker' -e 'PUID'='99' -e 'PGID'='100' -e 'UMASK'='022' -l net.unraid.docker.managed=dockerman -l net.unraid.docker.webui='http://[IP]:[PORT:32400]/web/index.html' -l net.unraid.docker.icon='https://raw.githubusercontent.com/linuxserver/docker-templates/master/linuxserver.io/img/plex-logo.png' -v '/mnt/user/appdata/plex':'/config':'rw' --device='/dev/dri' 'lscr.io/linuxserver/plex:1.42.2'

Container logs

Connection to localhost (127.0.0.1) 32400 port [tcp/*] succeeded!
[migrations] started
[migrations] no migrations found
───────────────────────────────────────

      ██╗     ███████╗██╗ ██████╗
      ██║     ██╔════╝██║██╔═══██╗
      ██║     ███████╗██║██║   ██║
      ██║     ╚════██║██║██║   ██║
      ███████╗███████║██║╚██████╔╝
      ╚══════╝╚══════╝╚═╝ ╚═════╝

   Brought to you by linuxserver.io
───────────────────────────────────────

To support LSIO projects visit:
https://www.linuxserver.io/donate/

───────────────────────────────────────
GID/UID
───────────────────────────────────────

User UID:    99
User GID:    100
───────────────────────────────────────
Linuxserver.io version: 1.43.0.10492-121068a07-ls293
Build-date: 2026-02-11T16:24:27+00:00
───────────────────────────────────────
    
**** creating group grouprup4 with id 18 ****
**** adding /dev/dri/renderD128 to group grouprup4 with id 18 ****
**** permissions for /dev/dri/card0 are good ****
**** Server already claimed ****
Docker is used for versioning skip update check
[custom-init] No custom files found, skipping...
Starting Plex Media Server. . . (you can ignore the libusb_init error)
[ls.io-init] done.
Critical: libusb_init failed

[github-actions]

Thanks for opening your first issue here! Be sure to follow the relevant issue templates, or risk having this issue marked as invalid.

[j0nnymoe]

I would suggest reporting this to plex, could be an issue with their release.

[CaptainPimpJr]

Appreciate your quick response, will do!
From Plex release notes, first beta of 1.43:

Plex Media Server 1.43.0.10162 is now available to Plex Pass users in the Beta update channel.

NOTE: While the transcoder update included in this release does not include any new features it has been refreshed from the ground up. Even though this has undergone significant testing internally as well as in a forum preview build we realize there still may be some issues to work out so this build will stay in beta for longer than usual to give us time to find and address any lingering bugs.

NEW:

(Transcoder) Transcoder was updated to the ffmpeg 6.1 baseline. (PM-3882)

I guess Plex should be made aware of the issue. Can be closed from my end.