Ubuntu 24.04 & HW transcoding

Plex Media Server Desktops & Laptops
47

Are you at liberty to share that we should expect weeks or months for this to finally be available? I’m not trying to be impatient but I’ve had issues with watching things with my friends for nearly a year, and last I heard Q1 this year was the target. It’s so bad I have to have subtitles off, which is not possible for some movies. I understand if you can’t share though.

48

I’m hoping weeks or less but we are battling a problem so I can’t reliably predict when the forum preview is available. I don’t know what else I can detail so please understand.

We had plans to be done by now but those were all scrapped with the staffing changes. We had no choice but to literally start over because there was no transition time from person to person.

At this point,

  1. PMS candidate changes are done (issues will be worked out in the forum preview)
  2. App profile changes are ready
  3. Some players will need augmenting ( I don’t know which ones )
  4. The transcoder is dependent on
    – Intel Compute Runtime for the iGPU systems . – Working this out now
    – Codecs next (99.99% of the time these are trivial updates and not full ‘upgrades’)

Potential stumbling block is the 6.8 kernel WITH the Intel Compute Runtime update.
This is the unknown time-to-complete until we’re done and it works for all iGPU systems we have in house (Haswell → RaptorLake… at minimum)

I’ve been testing every build candidate. I wouldn’t be surprised if the first one which doesn’t “Crash and Burn miserably” would be something I could bring to the forum as Forum Preview ( WITH A BIG CAVEAT )

6 Likes
49

Just FYI, there was a separate kernel regression too for 6.8.5+ kernels which also broke tonemapping (separate from the intel-compute-runtime issue):

50

Oh no. I wasn’t aware. I’m sorry to hear, and I’m sure that caused frustrations. I wish your team well and I hope you don’t get too many angry customers.

51

For my part, I prefer using “SRT” subtitles as much as possible. They are never subject to transcoding but rather played directly, and I avoid “PGS” subtitles as much as possible.

I think we’ll have to be patient and adapt until everything is back to normal.

2 Likes
52

Hi folks, what’s the actual state?
I build a new server, so what Ubuntu version works? 22.04 or 24.04?
thanks

53

22.04

2 Likes
54

I have booted Ubuntu 24.04 with my previous kernel GNU/Linux 6.5.0-35-generic x86_64 and the hardware decoding seems to be working okay.

55

Have you read the posts though? HW transcoding has always worked, it is HDR tonemapping that does not.

1 Like
56

I did and have just gone back and tested loading with both kernels. When I boot with 6.8 I don’t get HW transcoding with HDR tone mapping enabled. When I boot with 6.5 I do get HW transcoding with HDR tone mapping enabled. Am I missing something here?

57

No. That’s the bug.

58

Hi Chuck, do you still need the debug logs? I noticed this is 25 days ago and this issue is affecting me as well!

59

Good thread, got me to downgrade the kernel to 6.5 and now hw HDR is working. following to see if anything changes

60

fyi I also just completed a build this weekend 24.04 with 6.8. Couldn’t get HDR to work so just downgraded kernel to 6.5 and now it works like a charm.

61

ALL:

We’re good for the moment on investigation / debug logs.

We know exactly where and what all the breakage points are.

There’s fine tuning required on our end to fit into this new reality of the kernels & CPUs.

I don’t know all the details (I’m not full-time Engineering)

7 Likes
62

Hi @ChuckPa

Could you clarify which CPUs are affected by the kernel 6.8?

Does it affect Intel CPUs with Quick Sync before Tiger Lake only?

I.e.

  1. Appollo Lake to Ice Lake / Jasper Lake are affected, but
  2. Tiger Lake to Arc Alchemist / Meteor Lake / Arrow Lake have are unaffected and tone mapping works on all of them.
63

Do you know if the engineers are discussing having two installs, a legacy one for the older Intel CPUs/GPU’s and and an install for more modern CPUs/GPUs that will use vaapi tonemapping for example?

64

We are working on keeping it as one package.
Multiple packages based on CPU would be a logistic nightmare.

I can share this with you – (no details except we found where Intel made the change in ICR)

Screenshot from 2024-05-30 13-12-27
Screenshot from 2024-05-30 13-12-27904×553 63.5 KB

65

Issue seems fixes by kernel 6.9

66

Then it is actually a bad news.

The current Ubuntu 24.04 LTS is unlikely to switch kernel. It probably means we have to wait for Ubuntu 24.10 the earliest. :sweat_smile: