Posts by dziobak

Just to add some details about my LE11 vs LE12 comparison: I did quite a bit of low-level checking while actually playing the passthrough stream. I compared the relevant /proc and /sys entries, ALSA/device state and the kernel-side flags/parameters between LE11 and LE12. I also checked the state while the stream was actively playing.

I couldn't find any meaningful difference there: the same HDMI device is exposed, the relevant capabilities/flags look the same, and the kernel-side state during playback looks essentially identical.

The important part is that this is the exact same TX6, TV and HDMI connection: LE11 passes the bitstream correctly, while LE12 does not — the TV only detects LPCM and passthrough results in digital noise.

So I agree that Kodi audio handling is worth investigating. My tests just make it look less likely that there is a simple difference in the underlying HDMI/driver state between LE11 and LE12. Of course, there could still be a difference in the actual data/API interaction that isn't visible in /proc or /sys.

Thanks for the clarification! And also thank you for all the work you’re putting into supporting the TX6 — I really appreciate it.

Since passthrough is important to me and I don’t really have a good alternative for the TX6, would you recommend trying LE13 already, or is it better to wait for a more mature build?

I’m happy to test it if that could be useful.

Hello,

I have a problem with HDMI audio passthrough on a Tanix TX6 (Allwinner H6).

The important point is that the exact same hardware and TV work correctly with LibreELEC 11, while the problem occurs with all LibreELEC 12 versions I have tested.

LibreELEC 11

HDMI audio passthrough works correctly.

Kodi passes the supported encoded audio formats to the TV and the TV detects them correctly.

LibreELEC 12

I have tested multiple LE12 versions, including the last nightly build for Tanix TX6, and the result is always the same.

The interesting part is that everything appears to be configured correctly from Kodi's/system's point of view:

• HDMI audio device is detected correctly
• audio settings are available normally
• passthrough can be enabled
• the relevant passthrough codecs can be selected
• there are no obvious errors in the GUI

However, when playback starts, the TV detects only LPCM instead of the expected encoded format.

At the same time, instead of normal audio I get a digital crackling/noise ("machine-gun" / digital noise).

So the situation is essentially:

LE11:
Kodi → HDMI → TV → correct passthrough / correct audio

LE12:
Kodi → HDMI → TV → TV reports LPCM + digital noise

This happens despite the audio configuration looking identical/correct.

The hardware, HDMI cable and TV are unchanged between the tests. The only relevant change is the LibreELEC version.

I am therefore wondering whether something changed in the Allwinner H6 HDMI audio / ALSA / DRM HDMI path between LE11 and LE12.

Thank you!

I found it happens when player's playback "Adjust display refresh rate" is set to "Always".

Quote from Pretoriano

There's a PR for Kodi that might be related to your issue! Do you have overscan set? - > https://github.com/xbmc/xbmc/pull/21026

It is not related. This is fix for Kodi 20 (Nexus).

I checked, the problem also occurs on LE 10.0.1.
I used RPi with LE9 (Kodi Leia) before and there was no problem.

I checked VM version of LE 10.0.2 on my PC also, there is no problem here.
So this is related to hardware I think. Allwinner H6 version?

I did more tests and I was wrong. The problem is not the codec, but the video aspect ratio.
Incorrect subtitle position occurs at aspect ratio 1.85:1, 1.78:1.

For example video aspect ratio 1.78:1, subtitle position on video calibration settings

and same text but position much lower (below bottom of movie) after closing settings

I haven't found the problem (so far) when the aspect ratio > 2:1

I have a problem with the subtitle position (Allwinner H6 Tanix TX6 + LE 10.0.2). I'm fresh on LE 10, so don't know this is old or new bug.

I am not able to change its position with the setting "fixed" for x265 codec. When playing x264 video subtitle position follows calibration settings. In cause of x265 video - not.   <-- wrong conclusion, more in next posts

I used to change the subtitle position with the video calibration settings when playing a video. That is possible and I see the subtitle move when doing the calibration (calibration settings is on screen). But when I press back (and calibration closes), the position of the subtitle did not change (return to bottom of the screen). The position with the calibration is saved though. When I go back to video calibration, the subtitle line is still higher.

Trying this with and without PRIME, the problem occurs in all combinations.