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

**sky42** · December 18, 2023 at 1:49 PM

audio dropouts with screen resolution 2160p @ 23,976 Hz if the Audio is HD (for 9 out of 10 BD/4k remux i tested)

Use the workaround from post #46

affected devices tested
- ASUS PN42
- Intel NUC12WSKv7
- MiniX Z100-0db

not affected devices as counter tests
- RPi4
- Asrock B360/ITX-ac with Intel i3-8100 HDMI 1.4
- Intel NUC8i7BEH

Edit: workaround is here RE: Intel Alder Lake 2160p @ 23.976 Hz passthrough HD Audio dropouts (i7-1270p/N100)

setup used
- HDMI connections only
- no ARC
- no CEC
- LE device -> Denon X6700H -> LG 55E6D
- as of today a extra new clean installed USB disk for testing with local data to play

Started here RE: Time to upgrade my NUC. What's hot today?

my ASUS PN42 has audio dropout with screen resolution 2160p @ 23,976 Hz if the Audio is HD (for 9 out of 10 BD/4k remux i tested).
PN42 tests and counter tests
- if not extra stated all in passthrough with only HDMI PN42 -> Denon -> LG TV (no ARC, no CEC)
- build LE11 and LE12 with the latest updates today for that
- nearly all DTS-HD, TrueHD have dropout when played with screen resolution 2160p @ 23,976 Hz
- NUC8i7BEH does play all content fine 1080p/2160p with and without HDR (for LE11 HDR with my Generic-BT2020)
- NUC8i7BEH has a LSPcon MC2800 HW: 2.2 SW: 1.78 (from /sys/kernel/debug/dri/0/i915_display_info)
-my LSPcon MC2900 und MC2907 do not work with HD audio on the PN42
- source resolution does not matter if you play with screen resolution 2160p @ 23,976 Hz and it has HD audio it will have dropouts
- LE12 makes no difference
- Generic legacy makes no difference
- 4k HDR source material played in screen resolution 1080p @ 23,976 Hz has NO audio dropouts and HDR works too
- disable passthrough and do multichennel PCM works better but every couple of minutes i have a dropout
- mainly tested by switching between NUC8, PN42 and RPi4 and settings changes
- for test i did see parts of Alita - Battle Angel (2019) EAN 4010232073624 playlist 00800
- for test i did see The Fast and the Furious (2001) EAN 5050582731248
- content from NFS locally mounted with v4
- short tests with Aquaman (2018) EAN 5051890317377 english E-AC3 with Atmos plays flawless all other HD audio tracks with dropouts (2x DTS-HD, 1x TrueHD/Atmos)

I tested by seeing at leats 10min (if no dropouts) to be sure. Mostly in less then 5min i did get a droptout. Switched devices and setting many times. At the moment that looks like a N100 problem.
Now i tested my NUC12WSKv7 and it has the same dropouts.

NUC12WSKv7
- created a USB disk with a new clean installation of LE11 and local data to play
- so far the same problems as the PN42
- 2x movies both 2 errors https://sky42.libreelec.tv/testing/adl/ko…C12WSKv7.log.gz

I will formalize the test and create some clean logs.

**sky42** · December 18, 2023 at 1:55 PM

ToDo
- ~~test ADL10 image with older Intel GPU and check if 12 bit is fine there~~
- ~~check my i7-1270P if it is fine too with ADL10 image~~
- ~~open a bug https://gitlab.freedesktop.org/drm/intel/-/issues~~

workaround in post #46

**sky42** · December 18, 2023 at 3:39 PM

i7-1270p playback with log
https://sky42.libreelec.tv/testing/adl/ko…C12WSKv7.log.gz
one very loud 20MB log file from playing 2 movies
Both had 1 audio hickup in the beginning and shortly before stopping it.

Any other log creation request please specify what

**sky42** · December 19, 2023 at 9:29 PM

Thanks to the hint of smp i have now a Pipe wire LE11 BT2020 running.

Output is PCM stereo at the moment. Now i need to learn how to configure pipe wire for Kodi that passthrough is possible.

**smp** · December 19, 2023 at 9:35 PM

I think Pipewire should only be enabled with Kodi 21/LE12.

**sky42** · December 20, 2023 at 11:09 AM

smp now i have LE12 too, but the same problem just PCM stereo

all my images for testing are here https://sky42.libreelec.tv/testing/adl/
my LE12 builds are the 11.80.4 ones

lets see if i can learn how to configure pipewire
any help for pipewire config is very welcome

the build config i used is
--- new device with options like this for gbm and x11 ----
# PipeWire backend device
PULSEAUDIO_SUPPORT="no"
PIPEWIRE_SUPPORT="yes"
KODI_ALSA_SUPPORT="no"
KODI_PULSEAUDIO_SUPPORT="no"
KODI_PIPEWIRE_SUPPORT="yes"
ALSA_SUPPORT="no"

# the rest is copied from gbm
------------------------------------------------------------

**sky42** · December 20, 2023 at 5:14 PM

I need help for proper pipewire config.

After half a day testing and reading i do not get PT running ONLY PCM 2.0 is working.

pastekodi
https://paste.libreelec.tv/accurate-mantis.log

pw-dump
https://paste.libreelec.tv/crack-kite.log

**smp** · December 20, 2023 at 6:19 PM

I think lrusak said on slack he will look into it. Unfortunately I have very little experience with pw.

yamcenutzer · December 26, 2023 at 2:40 PM

Sorry for the cross post, just noticed the thread has moved here:

So here's the situation for me as of now (todays nightly LE12):

nuc11i3 -> denon 1703-->panasonic 65HZ2000

- audio is stable as long as no pass through is attempted (note the TV can already do all formats)

- passthru works for non hd formats

- passthru doesn't passthrough any hd

-- dts ma becomes dts-- trying trueHD (7.1 in my case) kills all audio, and the system needs to be restarted to regain any audio

- UHD (4k) - tv via tvh-client doesn't play with HEVC VAAPi. Sometimes even not with VAAPI disabled, could not determine yet why.

There may be other things, but these are the issues I have, that used to work in LE 9 (or was it 10, before the big change that also required new binary addons , like the tvh client , I forgot)

Also a request: can a intel specifc topic be opened, we have specific topics for all those puny toys, but not for generic. Or am I misisng something?

**sky42** · January 2, 2024 at 8:55 PM

New build from LE development branch with new Intel software did not make it better. I updated kodi too to fix the broken mysql support of 21b2.
If you want to try download here https://sky42.libreelec.tv/testing/12.0/

No success with PipeWire and passthrough. The test images i build for PipeWire are also on the download server.

I have no ideas anymore what to do.

So i will give up and very sadly send the two N100 back next week.

here is the source diff to LE master i usedhttps://http://github.com/LibreELEC/Libr…:11.80.5-240102

racemaniac · January 4, 2024 at 7:02 PM

Ah, i also made a thread about this issue, didn't notice it wasn't being discussed here already: Very short audio cut outs every ~5 minutes

I just did an experiment: i went into audio settings and just tried changing random settings to see if it would have any effect, and not 100% sure about it yet, but disabling "send low level noise" seems to have fixed the issue on my end. I just watched an entire episode of 50 minutes without noticing this happening at all, while before it was just like you said every 5 minutes or so audio would drop for a second.

Give it a try & see if it makes a change on your end. No clue how the settings could be related, but it seems to have worked on my end for some mysterious reason.

racemaniac · January 4, 2024 at 9:02 PM

Quote from racemaniac

Ah, i also made a thread about this issue, didn't notice it wasn't being discussed here already: Very short audio cut outs every ~5 minutes

I just did an experiment: i went into audio settings and just tried changing random settings to see if it would have any effect, and not 100% sure about it yet, but disabling "send low level noise" seems to have fixed the issue on my end. I just watched an entire episode of 50 minutes without noticing this happening at all, while before it was just like you said every 5 minutes or so audio would drop for a second.

Give it a try & see if it makes a change on your end. No clue how the settings could be related, but it seems to have worked on my end for some mysterious reason.

Hmm, tested a bit more now, still have the issue... Maybe it's z bit less now or I just happened to test on a file that for some reason didn't trigger the issue.

It would be nice to find a real fix for this issue though..

**sky42** · January 4, 2024 at 9:57 PM

Nope makes no difference.

To state that very clearly i have ONLY a problem with screen resolution 2160p + HD audio in passthrough. All other playback is perfect from what I tested.

**sky42** · January 4, 2024 at 10:13 PM

At the end of the week I will give up and send my Intel N100 back.

Anybody any helping tips whom I could ask for fixing this Intel problem or what part of software could be the problem? So I can ask there.

If not I will live for now with my new RPi5. If you do not measure it you can not tell the difference in speed of using it with LE if it is the RPi5 or N100. Yes less codecs in Hardware especially AV1, but for now I don't need AV1. I use it for days now with LE11 and it plays all my DVD, BD, UHD BD remux content just perfect.

**Da Flex** · January 4, 2024 at 10:25 PM

sky42 Does the N100 work with Ubuntu and Kodi on top?

**sky42** · January 5, 2024 at 9:01 PM

Oh boy get kodi on Ubuntu 23.10 with PT working was lets say interessting.
So i have now kodi 20 from the team kodi ppa running in 2160p @ 23.976 Hz. That did take way longer then expected.
- fixed framerate because not switching with wayland
- no HDR
and HD Audio PT has the same problem

It is ridiculous how hard it is get PT running on Ubuntu even with the team kodi ppa.
I ended up with starting kodi with KODI_AE_SINK=ALSA kodi
What a colossal waste of time.

Any other helping suggestions?
If not i give up to get N100 running.
That is very sad !!!!

**Da Flex** · January 5, 2024 at 9:55 PM

sky42 On my Kubuntu login screen I had the option to start an X11 or Wayland session. Since installing Kodi I also have a Kodi session available. Maybe one of those three sessions makes HDR possible.

I'm using JACK for audio output on Kubuntu (musician setup). Installing "ubuntustudio-audio" package pretty much did all the JACK setup. Anybody, who wants do advanced audio routing on Linux, should use JACK. It's made for that task. I never did audio PT with it, but in theory JACK should be the solution.

**smp** · January 5, 2024 at 10:51 PM

Try to force YCbCr 4:4:4 instead of RGB:

Diff

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 7816b2a..758f3dc 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2196,7 +2196,7 @@ intel_hdmi_output_format(struct intel_connector *connector,
 	if (connector->base.ycbcr_420_allowed && ycbcr_420_output)
 		return INTEL_OUTPUT_FORMAT_YCBCR420;
 	else
-		return INTEL_OUTPUT_FORMAT_RGB;
+		return INTEL_OUTPUT_FORMAT_YCBCR444;
 }
 
 static int intel_hdmi_compute_output_format(struct intel_encoder *encoder,
@@ -2215,8 +2215,8 @@ static int intel_hdmi_compute_output_format(struct intel_encoder *encoder,

	if (ycbcr_420_only && crtc_state->sink_format != INTEL_OUTPUT_FORMAT_YCBCR420) {
		drm_dbg_kms(&i915->drm,
-			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to RGB.\n");
-		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_RGB;
+			    "YCbCr 4:2:0 mode but YCbCr 4:2:0 output not possible. Falling back to YCBCR444.\n");
+		crtc_state->sink_format = INTEL_OUTPUT_FORMAT_YCBCR444;
	}

	crtc_state->output_format = intel_hdmi_output_format(crtc_state);
@@ -2247,7 +2247,7 @@ int intel_hdmi_compute_config(struct intel_encoder *encoder,
	    adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
		return -EINVAL;
 
-	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
+	pipe_config->output_format = INTEL_OUTPUT_FORMAT_YCBCR444;

	if (pipe_config->has_hdmi_sink)
		pipe_config->has_infoframe = true;

Display More

Other things to try: force 10-bit and 8-bit 2160p @ 23,976 Hz mode instead of default 12-bit (with libdrm proptest tool).

Also worth trying a custom EDID with "SCDC Present" bit set to "disabled".

IMO those dropouts are data errors related to Intel HDMI 2.0 implementation.