Posts by Krobar

Quote from cheeez

Cross test, 4k content, DD5.1, 23.976, 12.0.1 Generic,

1. Back to HDMI- HDMI cable = audio dropouts all 15 to 30 sec.

2. New, good, HDMI- HDMI cable = audio dropouts and complete interruption of playback.

3. Back to DP- HDMI cable =

Just to follow up on cheeez findings. The new Libreelec 12.0.1 release included an important kernel patch discussed here:
No HBR Audio with LSPCON - Trying to collect information - General Support - LibreELEC Forum

It fixes HBR audio streams for Paradetech and Synapitcs LSPCons (DP to HDMI convereter chips). It also seems to cause PCM >2 channels to no longer be bit perfect. It changes the output timings. Other might find 12.0.1 with a converter behaves differently/better.

Another thing of note is the newer Kernel in Libreelec 12.0.1 contains a fix for LSPCon bit streaming which fixes silence for TrueHD and DTSHDMA in some setups.

In some cases an option on the TV setting might be set to no scaling which can cause this too.

The Displayport selection is likely a non issue. Your NUC like uses a Displayport to HDMI 2.0 converter (AKA LSPCON) internally so Libreelec will see Displayport.

Any reason you are using bitstreaming? For your 3.1 speaker config providing Librelec outputs 3.1 OK there is no advantage to bitstreaming whatsoever, Libreelec/Kodi will decode to multichannel PCM with no quality loss at all. The main reason people use bitstreaming is to allow passthrough of DTS:X and Atmos data which Kodi cannot decode but if your setup is 3.1 that is irrelevant to you.

If you really want to fix bitstreaming it might be worth checking if an HDMI / LSPCON firmware update is available for your NUC. It is also worth trying one of the Libreelec nightly builds because they have a newer Linux Kernel which introduced a bitstreaming fix for LSPCONs which might fix DTS but wont fix the odd detection of DTS bitstreaming support without Dolby bitstreaming support.

Quote from chewitt

This image contains the patch from drm-tip (which was no issue to backport onto the LE kernel sources) and the channel allocation reorder patch that was suggested with RPi recently: https://chewitt.libreelec.tv/testing/LibreE…_64-12.80.0.tar

Let me know if the issue is resolved and/or whether the 4.0 > 5.1 workaround is required?

Could I be cheeky and ask for a build of 12.0 stable with that patch applied? I suspect this patch breaks bitperfect multichannel output in my setup (Bitperfect stereo / DTS CD is OK), this potential build would really help me confirm that and that it is not something else in the nightlies since.

I'm not sure what the root cause of this issue is. It is probably possible to save the EDID, edit it to remove 44Khz support and then use that. In theory that would allow you to retain HDMI passthrough and cause 44khz audio to convert to 48khz.

In System -> Audio maybe try setting fixed 48khz.

Quote from sky42

Wow that is very diligent.
I fear i can not add anything to that.
It was cheaper for me (if time is money) to use my Vero 4k+ in the last years for contents that demanded HBR and/or HDR.
Now i use my N100.
But as i said i will setup my i3-8100 one more time and do some test, but for sure not as many as you did.

In retrospect it wasn't a great use of my time; I've mainly proved what was already suspected that LSPcons are near universally bugged and the bugs vary quite significantly and are a lot worse for Linux than Windows. As general advice I will say the newer VMM7100 based HDMI 2.1 converters actually seem to be the best choice right now although will be interested in any results you have (As you have different converters/LSPCons).

The display refresh restrictions of the PS175 are at least easy to workaround with no quality loss with careful whitelisting (I discovered I have no 4K/50/25 non-hdr content) so at least I have a good working solution and it is nice to be off of Windows. The last remaining for me is the lack of bit perfect multichannel PCM with recent builds but I need to try some other builds to narrow down the cause (I'm not sure if it is actually an LSPCon issue, might be Kodi or something else).

Quote from sky42

Krobar Lets drag that LSPCon conversation here. I will dust of my i3-8100 and connect it again to my home cinema setup. One last time just for some tests. I use a N100 ans so far i am very happy (one problem, but i found a workaround).

These are my results for multiple LSPCons:

PS175 - Internal:
DP branch device present: yes
Type: HDMI
ID: 175IB0
HW: 1.2
SW: 8.64
Max TMDS clock: 600000 kHz
Min TMDS clock: 25000 kHz
Max bpc: 12

Windows HDR: Yes
Windows 4K Refresh Rates: All with HDR; <=50HZ without HDR broken
Linux HDR: Yes
Linux BT2020: Yes
Linux HBR Audio Bitstream: Yes
Linux Multichannel PCM Support: Excellent
Linux 4K Refresh Rates: All with HDR; <=50HZ without HDR broken

PS175 (Older Firmware) - Internal:
DP branch device present: yes
Type: HDMI
ID: 175IB0
HW: 1.2
SW: 8.44
Max TMDS clock: 600000 kHz
Min TMDS clock: 25000 kHz
Max bpc: 12

Windows HDR: No (Does work on Windows 10 1809 or earlier)
Windows 4K Refresh Rates: All
Linux HDR: No
Linux BT2020: No
Linux HBR Audio Bitstream: Yes
Linux Multichannel PCM Support: Excellent
Linux 4K Refresh Rates: All

Mcdp2900:
DP branch device present: yes
Type: HDMI
ID: MC2907
HW: 1.4
SW: 11.116
Max TMDS clock: 600000 kHz
Min TMDS clock: 25000 kHz
Max bpc: 16

Windows HDR: Yes
Windows 4K Refresh Rates: ALL
Linux HDR: Yes
Linux BT2020: No
Linux HBR Audio Bitstream: No
Linux Multichannel PCM Support: Ok (Only support 5.1 & 7.1 in some setups)
Linux 4K Refresh Rates: ALL

PS176:
DP branch device present: yes
Type: HDMI
ID: 176GB0
HW: 1.0
SW: 7.85
Max TMDS clock: 600000 kHz
Min TMDS clock: 25000 kHz
Max bpc: 12

Windows HDR: NA
Windows 4K Refresh Rates: ALL
Linux HDR: NA
Linux BT2020: NA
Linux HBR Audio Bitstream: Yes
Linux Multichannel PCM Support: Excellent
Linux 4K Refresh Rates: ALL

VMM7100:
DP branch device present: yes
Type: HDMI
ID: SYNAq
HW: 1.0
SW: 7.2
Max TMDS clock: 600000 kHz
Min TMDS clock: 25000 kHz
Max bpc: 12

Windows HDR: Yes
Windows 4K Refresh Rates: ALL
Linux HDR: Yes
Linux BT2020: No
Linux HBR Audio Bitstream: Yes
Linux Multichannel PCM Support: Ok (Only support 5.1 & 7.1 in some setups)
Linux 4K Refresh Rates: ALL

PS186:
DP branch device present: yes
Type: HDMI
ID: 186GA1
HW: 0.1
SW: 2.52
Max TMDS clock: 600000 kHz
Min TMDS clock: 25000 kHz
Max bpc: 12

Windows HDR: Yes
Windows 4K Refresh Rates: ALL
Linux HDR: Yes
Linux BT2020: No
Linux HBR Audio Bitstream: Yes
Linux Multichannel PCM Support: Yes
Linux 4K Refresh Rates: ALL
Notes: Weird colour space issues n Linux. LSPCon crashes on change of audio format so not really useable

Linux HBR Audio required the recent Linux patch in all cases.

Quote from sky42

Krobar You are welcome. I do not have answers or or solutions for questions/problems. I did give up a very long time ago to get my CFL + LSPCon wroking with all the things i want and Audio was a big Problem. I do have IIRC many Adapter with 4x PS176, 1x MC290, 1x MC2907 none was working perfect. The only LSPCon that did work correctly was a NUC8i7 with the MC2800, but that one you can not buy as a standalone adapter.

Do you see overly rich colours in the GUI when playing back content in BT2020? (The video itself looks very good)

I tried a Belkin PS176 based adapter. Behaviour was perfect with audio and all refresh rates supported but it did not support HDR by design (Firmware was 0x07 0x55, AKA 7.85)

Quote from sky42

Krobar done with 6.6.32

Just wanted to say thanks. I have a choice of issues depending on which LSPCON I use with my Coffeelake VMs but this build for the first time ever gives a better overall experience than Windows in my setup so am running Libreelec daily now for the first time.

BT2020 works with the onboard PS175 LSPCon with updated firmware. I assume it is not mainline because the GUI colours do not adjust?

I'm seeing a few other edge issues too which I think might be Kodi related. A sort of flicker / OSD only graphics corruption sometimes occurs in the GUI when switching TV channels (Swear I saw another user report this in the N100 threads) and my choice of game emulators seems far smaller than Windows (I wonder if this is related to the Kodi being a dev version).

The last issue I'm seeing is multi channel PCM is not bit perfect even with passthrough enabled (Stereo PCM is bit perfect, I tested that with some DTS CD albums). Not yet sure if this is related to the Bitstreaming kernel fix or something else but it is bit perfect in the LE12 official release although no DTS HD or TrueHD bit streaming works with that build/kernel.

Is it actually PCM output that is broken? Does playing FLAC or MP3 files work?

Quote from hagaygo

Hi

Not sure if this is kodi issue or libreelec.

I noticed when i connect RPI5 to my lg oled tv i can set high refresh rates for 1080p 1440p resolutions. (100/119.88/120).

After testing it , it works really well for few reasons :

1.When playing 23.976/24 FPS video , refresh rate can be 119.88/120 , also 30/59/60 fps videos can use same resolution.

2.GUI is much more snappier when not staying on 24/23.97hz after video play back (i know there is an option to restore refresh rate after video playback to 50/60)

By default , kodi seems to support only double refresh rate values, so i added to my advancedsettings.xml the following settings :

<video>
 <adjustrefreshrate>
   <override>
     <fpsmin>23</fpsmin>
     <fpsmax>23.999</fpsmax>
     <refresh>119.88</refresh>
   </override>
   <override>
     <fpsmin>24</fpsmin>
     <fpsmax>24.1</fpsmax>
     <refresh>120</refresh>
   </override>
   <override>
     <fpsmin>24.1</fpsmin>
     <fpsmax>25.5</fpsmax>
     <refresh>50</refresh>
   </override>
   <override>
     <fpsmin>49</fpsmin>
     <fpsmax>51</fpsmax>
     <refresh>50</refresh>
   </override>
   <override>
     <fpsmin>29</fpsmin>
     <fpsmax>31</fpsmax>
     <refresh>120</refresh>
   </override>
   <override>
     <fpsmin>59</fpsmin>
     <fpsmax>59.99</fpsmax>
     <refresh>119.88</refresh>
   </override>    
   <override>
     <fpsmin>60</fpsmin>
     <fpsmax>61</fpsmax>
     <refresh>120</refresh>
   </override>    
   <fallback>
     <refresh>50</refresh>
   </fallback>
 </adjustrefreshrate>
 <fpsdetect>2</fpsdetect>
</video>

Which works just great , 23/24/30/59/60 videos uses 119/120hz and 50/25 users 100 hz.

I have only one problem , when i try to play a 4k video , the resolution stays at 1080p , i guess since the RPI5/TV does not support 4k at 100/120hz.

Any one else tried using libreelec at 100/120hz ?

Thanks in advance.

Display More

I think the Pi5 is still only HDMI 2.0 so 100hz/120hz 4K is unlikely; some HDMI 2.0 output can do 4K/120 at 4:2:0 8bit but colour quality suffers badly in that case. In general you do no want to increase the refresh more than needed for that reason, for example you can do 4:4:4 12bit HDR at 24hz but it is not possible at 60hz.

Quote from sky42

Krobar Generic-BT2020 12.0.0-#240531 build and uploaded, but so far not even boot tested

Thanks. It boots fine and BT2020 works with my PS175 LSPCon (Other brands do not seem to work). Any chance you could either bump the kernel to 6.6.31 or include the small LSPCon audio patch we have been dicussing here:
No HBR Audio with LSPCON - Trying to collect information - General Support - LibreELEC Forum

The patch seems to fix HBR audio bitstreaming for Paradetech and Synaptics LSPCons (And maybe others).

Any chance of some updated builds? Kernel 6.6.31 (And hopefully 6.9) contains an important audio fix for LSPCon users and I'm keen to try the BT2020 build.

Well some interesting results with PS176 and mcdp2900 based LSPCons.

The PS176 product has no HDR support otherwise behaves impeccably. The mcdp2900 supports HDR and all refresh rates but is the only product after the audio patch which fails to playback bitstream audio and suffers from the same limited multichannel PCM support as the VMM7100. fezster Was the first converter you tried Megachips based?

Quote from fezster

I tried this. The Denon input options are also set to "8k Enhanced". If I set to just "Enhanced", then the behaviour is the same as my CBL/SAT (non-8k) input.

Firstly, I have an HDMI switch before my Denon, and using the 8k input in 8k Enhanced mode, I could not get LibreElec to show any output. My Sky Q works fine.

Connected directly from LibreElec to the 8k input.

Following refresh rates worked at 4k: 60/59.94/50/30/29.97/25/24.

Following refresh rates did not work at 4k: 23.98. This means 4k/24p switching does not work (I get no output).

I confirmed the channel mappings for 3.0/4.0 etc all worked as expected in all scenarios.

HTH.

Display More

Thank you for trying that. I don't have the same option for my Arcam. Interestingly the Arcam/Harman units use the same brand of chipset (Panasonic) as your Denon/Marantz unit and have the same 2in/2out hdmi processor but the switching chips are the HDMI 2.0 model on your 2700h where as the HDMI 2.1 Arcams use the same HDMI 2.1 switching solution as the Denon X800h units.

I will get other two main brands of LSPCon to test with later today. Hopefully patterns/consistencies will start to emerge if more people contribute to this thread.

Quote from fezster

I can confirm the HD Audio/LSPCON fix is working as part of Kernel 6.6.31. The change seems slightly more involved than the single line patch file, but works as expected.

https://git.kernel.org/pub/scm/linux/…/log/?h=v6.6.31

drm/i915/audio: Fix audio time stamp programming for DP

Chaitanya Kumar Borah

Nightlies just went to 6.6.31 for RPi; hopefully the generic kernel will be updated soon too.

If you could confirm any behaviour differences for refresh rate and PCM channel support when using the 8K input on your Denon that would be really useful.