Release T3b

[pannal]

p3i T3b

Maintenance bugfix release for the issues T3a introduced or didn't fix. T4 is in development.

This release fixes:

• specific issues with certain skins that were introduced with T3a (missing OSD, missing elements)
• very rare SDR content with BT2020 (skips VS10 SDR conversion for those) being misrepresented as BT.709
• TrueHD dropout issues introduced with T3a; rare

Changelog

xbmc/Kodi:

• OSD: fix conditional includes broken by texture caching
• DV: bypass VS10 for SDR BT.2020 content to preserve gamut
• Settings: Fix description for Reduce color banding (VS10) not representing the default
• Revert MAT packer Reset on seek for standard passthrough path
• Settings: Default refresh rate change delay to 2.5s

Note

If you're not initial flashing, you might want to set the Delay after refresh rate change to at least 2.5s if you're using PM4k.

CoreELEC Settings Addon:

• Fix 30s reboot delay from D-Bus agent unregister

--

p3i T3a

While this release was meant as an intermediate "bugfix" release, it added and improved a couple of features as well.
Most notably:

Dialnorm EAC3 JOC exclusion

You can now select whether you want dialnorm to apply to EAC3 with JOC (Atmos) or not. This should be disabled for people who want the Atmos metadata and enabled for people without Atmos capabilities, as it will properly normalize dialogs here, as well (throwing away the Atmos caps)

Image based subtitle love

We now have the option to more correctly follow PGS subtitle's color representation. If you like the old way better, you can disable this feature in Settings/Subtitles. For color space/gamut conversion we've added multiple blending modes that you can select from, just choose what suits your needs (defaults are always sane).

Apart from that we've added smart image based subtitle scaling - you can now resize them to your liking and they'll be scaled and positioned correctly.

Changelog

xbmc/Kodi:

• Fix TrueHD audio dropouts after chapter skip
• Skip E-AC-3 dialnorm defeat for DD+ Atmos (JOC) streams (optional)
• Add setting to optionally include DD+ Atmos in dialnorm defeat
• VideoPlayer: rate-limit UpdatePlayerInfo to 10Hz (via @cpm-code)
• Fix m2ts DV FEL black screen caused by premature EL starvation flushing
• DV: add setting to skip DV activation for windowed playback
  This helps with skins using embedded trailers, as we now skip HDMI renegotiation in this case. Disable this if you have a background image screensaver that uses DV
• PGS/DV: add PQ→SDR shader for HDR PGS subtitles in DV/HDR10 modes
• PGS: match Core2 g_2_l curve and fix full-range output for DV mode
• PGS: add tonemap mode setting (Classic/Linear/Luma)
• OSD: prevent texture reloading to avoid frame drops on open
• DV: add setting to reduce color banding in VS10 (VPP 12-bit dither) (default on)
• PGS: add brightness percentage
• DV: re-couple OSD base brightness slider to VS10 modes
  The previously decoupled brightness slider under Settings/Display is now re-coupled to VS10. It sets the base brightness of the OSD/Subtitles. The VS10 peak brightness settings are "on top"

Kernel:

• amdolby_vision: enable RGB->YUV post matrix for VS10 SDR output
• amdolby_vision: fix false DV detection for SDR content with T35 SEI
• amdolby_vision: add xbmc_dv_dither param to reduce VS10 color banding

Installation

1. Dirty

Drop the update tar into your CoreELEC update folder and reboot - this can be used as a dirty upgrade from CPM A14 or any of the U3k and avdvplus builds.

Should hitting reboot result in a black screen (long standing issue with any build), wait 10 seconds to make sure this wasn't just a fluke, then unplug and re-plug the device's power. The upgrade will commence afterwards.

Caution

Resetting Settings/System/CoreELEC to defaults after doing this is necessary. Not the CoreELEC Settings Addon!
Resetting Settings/System/Audio might be necessary for you to see the new settings (dialnorm)

2. Dirty (safe)

Drop the update tar into your CoreELEC update folder, shut down the device, pull the power plug for 30 seconds, replug.

Reset Settings/System/CoreELEC, reboot.

Caution

Resetting Settings/System/CoreELEC to defaults after doing this is necessary. Not the CoreELEC Settings Addon!
Resetting Settings/System/Audio might be necessary for you to see the new settings (dialnorm)

3. Flash

Use the provided Flash img.gz to prepare your SD card as you would with any other CoreELEC build.

advancedsettings.xml

If you'd like, you can add the following to your advancedsettings.xml, which further improves UI rendering, but is not strictly necessary:

<advancedsettings version="1.0">
  <gui>
      <fronttobackrendering>true</fronttobackrendering>
      <geometryclear>false</geometryclear>
  </gui>
</advancedsettings>

Make sure the XML format is correct, otherwise the file will not be read at all. If you already have such a file, only add the <gui></gui> parts.

Thanks

A massive shoutout to everyone involved in this build!

Full Changelog (Kodi core): https://github.com/pannal/xbmc/commits/T3a
Full Changelog (CoreELEC-Settings): https://github.com/pannal/service.coreelec.settings/commits/T3a
Full Changelog (Kernel): https://github.com/pannal/linux-amlogic/commits/T3a

---

This discussion was created from the release Release T3a.

[squaleca]

what are the proper system coreelec settings for samsung tv's s90d qd oled unmodded to be precise? also have 990b soundbar should i use full or sb?

[nissel]

The defaults are pretty good, so start with resetting the System > CoreElec settings. Then just up the default max nits in the VSVDB section from 1000 to 1200 for an s90d.

Generally audio fixes is fine set to off, so I'd try it on that first and only use the other options if you have any problems.

[andruhin64]

Почему вы не иправляете проблему с кодеком vc1 на s905x4 из за которого изображение идет с белой рябью. У avdv это уже испраалено. Скопируйте у него.

[PetroDeineka]

I tested using USB output to a 2-channel DAC, and via S/PDIF to a 2-channel audio codec built into the speakers.

Passthrough - Off

LAV Audio – Full
Maintain original volume on downmix – Off
(Select how is downmixed, e.g. from 5.1 to 2.0)

Disabling this option works only for AC3 and E-AC3, where the volume level is very close to how it behaves in LAV Audio on PC. However, it does not work for DTS-HD MA and TrueHD. For these two formats, the downmix results in a reduced dynamic range.
It's possible that the dynamic range remains the same, but the sound is simply overloaded and, as a result, less clear, and may clip.

When Maintain original volume on downmix is set to On, the volume is consistent across all formats.

In LAV Audio on PC, matrix normalization behaves consistently across all formats.

Is it possible in a future update to make the dynamic range during 2.0 downmix for DTS-HD MA and TrueHD as wide as it currently is for AC3 and E-AC3 in CoreELEC and in LAV Audio on PC?

Is it possible to use LAV Audio–style downmix in CoreELEC, similar to how it works on PC?

Or to make Maintain original volume on downmix = Off behave the same way for DTS-HD MA and TrueHD as well?

[pannal]

When Maintain original volume on downmix is set to On, the volume is consistent across all formats.

Why don't you use this if it works? I'm missing that crucial point.

[pannal]

@PetroDeineka probably found a fix. Please join the Discord so you can verify in a dev build, thank you!

[PetroDeineka]

When Maintain original volume on downmix is set to On, the volume is consistent across all formats.

Why don't you use this if it works? I'm missing that crucial point.

Because in that case, all formats will be overloaded during downmixing.

[PetroDeineka]

@PetroDeineka probably found a fix. Please join the Discord so you can verify in a dev build, thank you!

Please send me a link to Discord

[pannal]

https://trash-guides.info/discord

[andruhin64]

Why aren't you fixing the problem with the VC1 codec that's causing the white ripples? AVDV fixed this problem a long time ago. Copy it from him.

[pannal]

Because it wasn't a priority. Can you explain the issue in more detail or give some reference? That'd help.

[andruhin64]

On s905x4 processors, when playing files in the vc1 codec, there is a white ripple on the image.

[pannal]

I can take a look, but we're more optimized towards S922XJ, not S905X4. For the latter you should use avdvplus.

[webpredator]

Hello & thanks a lot for your continued work - i've been following you since 2024 - PM4k

Must inform of a bug (or at least something that happened between T3 and T3a, this is what i'm comparing)

Context : Dirty installed T3a over T3 + CoreElec settings reset to default as suggested / AM6b+ / Passthrough sound enabled

Affected are files with Atmos tracks (loseless Atmos, Dolby TrueHD)
Issue : They crackle and on an LG TV they dropout for a split-second and trigger the Dolby Vision flag (when running Dolby Vision 4K files)
So crackling / micro-dropouts - this DID NOT happen on T3 only happens now on T3a

What i did :
I've tried ALL settings - all Audio Fixes ON as well as Audio Fixes off
I've tried disabling the "normalization" check and also the new EAC3 JOC (although it's not related to Dolby TrueHD)
It does the same
So there's that, hopefully i can help more to diagnose this issue.

[webpredator]

I would need to reinstall T3a again to test this - doing this now and reporting back

I remember the cracking happening upon seeking / chapter skipping - all the time, not just in a particular situation, very easy to reproduce.
PM4k with alternate seek and auto seek back on start - yes, both enabled
Should i disable anything and test? Ok - will do

Sure, i can join the Discord thread, alright

[pannal]

Awesome. I'll probably have a test build for you ready once you join.

[webpredator]

Ok, here are my findings

-When seeking / resuming - it does happen all the time, no exceptions.
Tried disabling alternate seek / auto seek back on start - Same
Audio fixes : off

BUT
-When playing an mkv from the beginning it doesn't happen at all

How can we get in touch on Discord ?
I have joined (webbos - nickname)

[pannal]

Will be fixed in T3b.

[pannal]

Fixed in T3b.

[PetroDeineka]

I noticed that there is an option to choose chromatic upscaling methods. But I see that this only works for 1080p SDR = 100% scaling

Could you provide a complete list and explain how they affect the image, as each has its own characteristics?

Here are a few screenshots to help illustrate how some of them work.

[pannal]

Is that a setting p3i has introduced? If not, this is out of scope and can be googled separately I guess.

[pannal]

Updated discussion to T3b.

[PetroDeineka]

You can added support 4.4.4. video like this https://thedigitaltheater.com/dune-part-two-2023/ ?

[pannal]

Thanks for the answer. Then why the setting in the 4.4.4 system. What does it give, how does it work, when should it be turned on, and does it make any sense at all? Does it only work with DV P7 FEL?)

My TV can decode 4:4:4 in certain cases, but as far as I understand, 4:2:2 is the mode you normally want. We do have "Auto" as an option, though.

[PetroDeineka]

I think my TV can only handle 4.4.4 in PC or Game mode. These modes aren't available when the TV box is connected. From what I understand, this TV box simply can't handle 4.4.4 video.

[pannal]

I think my TV can only handle 4.4.4 in PC or Game mode. These modes aren't available when the TV box is connected. From what I understand, this TV box simply can't handle 4.4.4 video.

Quite sure it can.

[nissel]

@pannal the box can output 444, but @PetroDeineka is talking about a 444 encoded file, the SOC simply can't decode that, it only supports H.265 HEVC Main 10 which is limited 420 and that's what all content uses. Maybe it could via software with hardware acceleration off, but it's not going to be fast enough for 4k.

[pannal]

Ah, gotcha, thanks!

[icebr3aker788]

Hi,

I just did a fresh install of T3b, before everything worked great, now when i play a movie/tv show and try to change from SDR to DV via the VS10 I only get a red Picture output (see Screenshot) it seems DV isn't triggered on the TV previously everything worked great while being set to TV LED

Now it only works when I use Player Led 4:2:2
.
Then went back to T3 did the Resetting Settings/System/CoreELEC to defaults but still no luck

Steps to reproduce the behavior:

Set VS10 to TV-Led Go to any Library via pkc
Play any movie / tv title and try to change from SDR to DV
See error: DolbyVision on the TV isn't triggered and get only red tinted Picture


LibreELEC Version: p3i T3b / p3i T3
Hardware Platform: Ugoos AM6B+ / Philips OLED 837 / Denon AVR X1700H

 CoreELEC (p3i): 21.3-Omega_p3i_T3b_20260322020632 (Amlogic-ng.arm)
Machine model: UGOOS AM6B
CoreELEC dt-id: g12b_s922x_ugoos_am6b
Amlogic dt-id: g12b_AM6b_b4g
Linux version: 4.9.269 (panni@pannal) https://github.com/pannal/CoreELEC/discussions/1 Tue Mar 17 15:40:32 CET 2026
Kodi compiled: 2026-03-22 01:08:25 +0000

CoreELEC:~ # journalctl -l | grep -i dovi
Apr 07 00:22:01 CoreELEC kernel: g12 dovi disable in uboot
Apr 07 00:22:02 CoreELEC dovi-loader[3657]: run dovi 'start' for ng
Apr 07 00:22:02 CoreELEC kernel: dovi: disagrees about version of symbol module_layout
Apr 07 00:22:02 CoreELEC kernel: dovi: module license 'AML' taints kernel.
Apr 07 00:22:02 CoreELEC kernel: dovi: disagrees about version of symbol register_dv_functions
Apr 07 00:22:02 CoreELEC dovi-loader[3657]: loading '/flash/dovi.ko' module
Apr 07 00:22:02 CoreELEC dovi-loader[3713]: filename: /flash/dovi.ko
Apr 07 00:22:02 CoreELEC dovi-loader[3713]: license: AML
Apr 07 00:22:02 CoreELEC dovi-loader[3713]: description: Amlogic Dolby Vision Driver
Apr 07 00:22:02 CoreELEC dovi-loader[3713]: depends:
Apr 07 00:22:02 CoreELEC dovi-loader[3713]: vermagic: 4.9.y SMP preempt mod_unload modversions aarch64

`

did a fresh install of T3b but still no luck with TV-LED Dolby vision,

can anyone please help

[PetroDeineka]

When I download a new movie to an external SSD and delete the old one, and then plug the SSD back into the Corelec TV box, the list doesn't update like it does on a PC. It shows the old list, the deleted file won't play, and the new one doesn't appear—until I reboot the system.

[pannal]

How about you check your previous discussions for answers first, before posting yet another one? :)
#32 (comment)

[PetroDeineka]

How about you check your previous discussions for answers first, before posting yet another one? :) #32 (comment)

Sorry, I didn't see your reply. I'll reply now, thank you.

[tominkozhimala]

Regarding the dirty installation instructions: I am currently on CoreELEC 21.2 + CPM A14 on my device eMMC.

At what point should I upgrade CE to 21.3 during this process? Is it necessary to do before or after dropping in the TAR file?

[pannal]

Doesn't matter. You can dirty upgrade directly as per instructions.