Intel Alder Lake 2160p @ 23.976 Hz passthrough HD Audio dropouts (i7-1270p/N100)

**sky42** · January 6, 2024 at 10:20 AM

Da Flex thanks for the info, but at the moment i dont feel going down that rabbit hole

smp How do i edit the edid and change "SCDC Present"? Nerver done that before. I just refreshed my edid collection https://sky42.libreelec.tv/testing/edid/. Kernel LE12 with your patch is building. Thanks.

**sky42** · January 6, 2024 at 10:59 AM

smp tested YCBCR444 patch: that does not change the problem.
Oh and another question how do i force 8 Bit or 10 Bit. I have no idea.

Edit: I verified the YCBCR444 on the Info screen of my Denon and there is now YCBCR444 and not RGB both with 12 bit

Edit 2: found libdrm proptest binary in my buildtree and copied it to the N100 and here is the output https://paste.libreelec.tv/elegant-cockatoo.log

**sky42** · January 6, 2024 at 11:58 AM

orby you said here
RE: HDR on x86 Hardware
"audio at 24hz and gives random blips research looks to be the linux driver at fault for that"
can you point me to the right software that is the fault or even better a open bug?

That reads like the problem of this thread.

**sky42** · January 6, 2024 at 1:38 PM

w46n3r your hint was very helpful and works for me too (at least the fist 10min)
RE: HDR on x86 Hardware

Just disabling 2160p @ 23.976 Hz and play it at 2160p @ 24 Hz fixes the audio problem and HD audio pass though still works despite the not matching frame rate / refresh rate.
Workaround settings LE11:
System -> System -> Display
- Resolution 3840x2160
- Refresh 24 Hz
- GUI resolution limit 1080
- Whitelist what you want BUT without 3840x2160 23.976 Hz
for me that is 3840x2160 in 60, 59.94, 50, 30, 29.97, 25, 24
System -> Player -> Videos
- Adjust display refresh rate On Start / Stop

What does it do? If kodi does not find a matching refresh rate in the whitelist it plays in the screen resolution / refresh rate that is on right at starting playback. We set screen resolution to 3840x2160 with 24 Hz and change refresh on start and stop. So at start kodi find a better resolution / refresh rate it switches, but if it does not find a better one it uses the 3840x2160 with 24 Hz the GUI is running right now at start.

LE12 behaves a little different and i had not the nerv to test it trough, but in LE12 you can change playback resolution in the settings for the playback (LE11 does not have that).

Now i go back an finish the movie to see if it really works the whole time.

**smp** · January 6, 2024 at 1:52 PM

Quote from sky42

how do i force 8 Bit or 10 Bit

For 8-bit:

Code

systemctl stop kodi
./proptest 185 connector 191 8
systemctl start kodi

Quote from sky42

How do i edit the edid and change "SCDC Present"?

I used this. It's in CEA Extension 1 -> HDMI-Forum VSDB.

**sky42** · January 6, 2024 at 8:46 PM

smp you are the man: forcing 8 or 10 bit both fixes the problem. What impact has it to only use 10 bit instead of 12?

Forced 8 bit test 30min and 10 bit 60min without a audio glitch playing 1080p BD remux TrueHD Atmos at 2160p with 23.976 Hz with audio pass through.
Tested with my LE 11.0.4-#231221 Generic-BT2020 on my ASUS PN42. Most likely any LE11 or LE12 will be fixed by that.

new workaround
- download proptest for LE11 or LE12 https://sky42.libreelec.tv/testing/proptest/
- make it executable (and rename if you like)
- run it and find out your active Connector number
- systemctl stop kodi && ./proptest <your number> connector 191 10 && systemctl start kodi
- dont forget to enable 3840x2160 @ 23.976 Hz in you whitelist

A more convenient way of doing that would be put proptest <your number> connector 191 10 in autostart.sh

I will test some more.

Has anybody any pointers where i could open a bug for that? Intel media driver, linux kernel or Intel guys who maintain the linux parts for Intel. I am not sure what software part ist responsible for that problem, so i dont know where to open the bug.

**smp** · January 6, 2024 at 9:45 PM

Quote from sky42

What impact has it to only use 10 bit instead of 12?

None whatsoever.

Quote from sky42

Has anybody any pointers where i could open a bug for that?

Issues · drm / intel · GitLab

Intel Graphics for Linux - drm/i915 kernel driver repository. For issues only for now.

gitlab.freedesktop.org

**sky42** · January 6, 2024 at 10:18 PM

verified 4k HDR playback UHD BD remux TrueHD Atmos played perfect too in a 30min test

verified autostart.sh workaround activation and uploaded my autostart.sh to https://sky42.libreelec.tv/testing/proptest/

**smp** · January 7, 2024 at 1:15 AM

Diff

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index bc97591..3da321f 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -1895,7 +1895,7 @@ static bool intel_hdmi_source_bpc_possible(struct drm_i915_private *i915, int bp
 {
 	switch (bpc) {
 	case 12:
-		return !HAS_GMCH(i915);
+		return !HAS_GMCH(i915) && DISPLAY_VER(i915) <= 10;
 	case 10:
 		return DISPLAY_VER(i915) >= 11;
 	case 8:

Display More

^ This can be used to force 10-bit instead of proptest. This will disable 12-bit for newer Intel hw that can support 10-bit. 10-bit is only supported since Ice Lake.

**sky42** · January 7, 2024 at 5:05 PM

smp thank you so much! I will build LE11 and LE12 images next week (today family party)

jordiboy · January 8, 2024 at 10:30 PM

I spend more hours on my MomentPlus N100 than I care to admit. The first issue was video would drop completely when switching from a text screen to anything with graphics. Examples, the change when LE installer goes from text to graphics, same for Debian. It worked with Fedora and has worked since then, but only when I use a thunderbolt to HDMI adapter. The two HDMI ports still lose the signal and put the monitors in "no device detected mode".

Even using the thunderbolt to HDMI adapter, the video still drops if I change my receive to any other device. Come back to the N100 and it is a blank screen. LE is still accessible via SSH and SMB so it isn't an LE problem.

Multiple people seem to be using some of the BeeLink N100s fine with LE, per the reviews. I am not sure if my experiences are due to the specific manuf or the N100 in general.

I typically don't like to admit defeat with tech, but I am ready to scrap the N100 at this point. I have been using Kodi since it was XBMC on the original XBOX and used various platforms along the way, but this has been a bigger time sink than the rest of my XBMC and Kodi builds combined.

The price point on the N100 is better than a RPi, but the time wasted has been painful.

**sky42** · January 9, 2024 at 1:39 AM

here is a new Generic device with a patch of smp that restrict playback to 10 bit on Intel 12th CPUs and later and in doing so HD Audio playback is perfect in 2160p @ 23.976 Hz and UHD BD works still too with HDR.

https://sky42.libreelec.tv/release/11.0/G…/Generic-ADL10/

Not yet well tested, but it works for me (the last 90min) in solving ONLY the problem of this thread without using one of the 2 workarounds i described here (so remove them when you use this image).

jordiboy I have a Intel N100 HUNSN BM34 too that is lets say interesting, that one i will send back. A bit cheaper as my ASUS PN42, but the ASUS PN42 is the perfect LE x86_64 box in my opinion. Hopefully this 3rd workaround fixes my last Problem.

**chewitt** · January 9, 2024 at 6:45 AM

smp sky42 I'm wondering if any of the RPi patches related to bit-depth might avoid kernel hacking? See: https://github.com/LibreELEC/Libr…th-videos.patch and other patches in the same folder.

**sky42** · January 9, 2024 at 2:24 PM

Edit: fxied the ADL10 version in 11.0.4-240109
~~Heads up cifs/nfs4 OS mounts broken in my ADL10 images. Kodi still can do smb/nfs directly.~~
https://sky42.libreelec.tv/release/11.0/G…/Generic-ADL10/

chewitt I see your point, doing that is not my forte. The kernel hack is very specific to the GPU generation and i am not sure one could do that in kodi too.

**smp** · January 9, 2024 at 2:32 PM

Quote from sky42

and i am not sure one could do that in kodi too.

Also those kodi patches are for DRMPRIME which we don't use on x86.

isamudaison · January 10, 2024 at 5:03 PM

Just reporting that using sky42 's build above, my Sony TV no longer struggles to lock on to mode switches via an n100-powered Kodi. It seems the [email protected] mode is quite buggy on the intel side.

**sky42** · January 10, 2024 at 6:55 PM

So now i established my new baseline where i can reproduce a working and a non working version with LE11 and LE12

LE11 11.0.4-#240109 https://sky42.libreelec.tv/release/11.0/G…/Generic-ADL10/
- Generic-ADL10 is working perfect for me with Intel N100
- Generic-BT2020 is the counterpart without the 10 bit patch as the only difference
- tested 1 movie 1st BT2020 after 3x (about 5mnin) audio glitches switch to ADL10 and the rest was flawless
- sources https://github.com/sky42src/LibreELEC.tv/tree/11.0.4-240109

LE12 11.80.5-#240109 https://sky42.libreelec.tv/testing/12.0/G…/Generic-ADL10/
(i would not use LE12, because kodi + mysql is at the moment very wonky and OS nfs4 is broken too)
- 2x downgrades in my 11.80.5-#240109 release to get mysql and OS nfs4 working
- Generic-ADL10 is working perfect for me with Intel N100
- Generic is the counterpart without the 10 bit patch as the only difference
- tested 1 movie 1st Generic after 3x (about 3min) audio glitches switch to ADL10 and the rest was flawless
- sources https://github.com/sky42src/LibreELEC.tv/tree/11.80.5-240109

PaJoe · January 15, 2024 at 6:58 PM

sky42,

The Asus web site has the PN42 configured with windows or barebones with no operating system. Which one did you buy? I would prefer not buying Windows, but need to make sure I get the same hardware that is working for you. I see a lot of cheaper mini pc systems on Amazon with the N100 processor but afraid buying the wrong one might create problems not yet resolved.