My Libreelec is not capable of Dolby Digital Plus DD+ passthrough on Raspberry!

trent · June 28, 2019 at 3:08 PM

I suggest update to LE 9.0.2

I do not have reason to suspect this is the cause, but it is better to update so we can rule it out as a cause

novalis · June 28, 2019 at 3:24 PM

Quote from trent

I suggest update to LE 9.0.2

I am on 9.0.2, only the log was made on an earlier version.

novalis · June 28, 2019 at 3:25 PM

Quote from dersascha

Hi guys i am at the lates aplpha on my Raspberry Pi 4 4GB but i notice some screen Tearing when i am in the settings or so. is a known probleme and maybe a fix for it?

wrong bus

novalis · June 28, 2019 at 3:26 PM

Quote from sky42

Around 10 diffrent DD+ samples I tested from my library play well on RPi2 and RPi4 from 5.1 up to DD+ 7.1 with Atmos, where my Denon AVR says Dolby Atmos. Tested with 9.2 latest git version.

That is really great.

trent · June 28, 2019 at 3:38 PM

Here is a log of DD+ successfully passthrough-ing for me.

Code

https://pastebin.com/uRrRTAYW

Understanding exactly what is happening in the logs is above my abilities but to me it seems like your Pi is sending out DD+ in exactly the same way as mine. Perhaps your receiver is at fault? Is there an update for it?

**Da Flex** · June 28, 2019 at 4:22 PM Official Post

novalis:

You don't use the default skin, and this is in your log:

Code

13:11:58.476 T:1937388192   ERROR: Window Translator: Can't find window osdaudiodspsettings

Try the default skin.

novalis · June 28, 2019 at 8:30 PM

Hi trent and Da Flex, you have to remember that I have the exact klone of Kodi running under Windows and there it works fine.

Have tried the default skin anyway, same result.

I also have tried to switch HDMI cables and conectors at the AVR, all without success.

It is somewhere in the LE / RasPi. But officials here a not keen on investigate that.

**Da Flex** · June 29, 2019 at 12:38 AM Official Post

Thanks for trying the default skin. Please post the output of this command:

Code

cat /storage/.kodi/userdata/guisettings.xml | grep passthrough

What's the precise model name of your RPi3? Do you use additional audio hardware, like a HiFiBerry at the GPIO?

novalis · June 29, 2019 at 8:43 AM

Code

############################
LibreELEC (official): 9.0.2 (RPi2.arm)
KODI-TV:~ # cat /storage/.kodi/userdata/guisettings.xml | grep passthrough
    <setting id="audiooutput.ac3passthrough" default="true">true</setting>
    <setting id="audiooutput.dtshdpassthrough" default="true">false</setting>
    <setting id="audiooutput.dtspassthrough">true</setting>
    <setting id="audiooutput.eac3passthrough" default="true">false</setting>
    <setting id="audiooutput.passthrough">true</setting>
    <setting id="audiooutput.passthroughdevice">PI:HDMI</setting>
    <setting id="audiooutput.truehdpassthrough" default="true">false</setting>

No additional audio hardware. Model is Raspi 3 B+

**Da Flex** · June 29, 2019 at 8:37 PM Official Post

Go to "Settings -> System -> Audio" and set all values back to default by using the last menu entry.

This will deactivate audio pass-through!

You want to have DD+ for Netflix. You actually don't pass-through the audio, because the audio source is the RPi itselve.

novalis · June 29, 2019 at 10:40 PM

Sorry Da Flex that makes no sense. First of all it would setup audio output to Stereo. But even if I chose 5.1, if I deactivate passthrough, audio is send as PCM and the Receiver doesn't recognize the format anymore -> shows Multi Channel In.

And also the RPi is not the audio source, the source is the audio stream itself and the question is whether Kodi should decode it and send it as PCM to the receiver or should it be passed to the AVR as it is and let the receiver do the job of decoding. Later is the option I want of course.

**Da Flex** · June 29, 2019 at 10:50 PM Official Post

Do you have DD+ audio with the suggested default values on Netflix?

We can talk about sense and details later.

**Da Flex** · June 29, 2019 at 11:34 PM Official Post

PS: Trust me, it makes sense.

noggin · June 30, 2019 at 5:30 AM

I think Da Flex is talking about getting the Raspberry Pi to decode DD+ to PCM in the Pi, whereas Novalis wants passthrough/bitstreaming, where the DD+ bitstream is passed, untouched, from the Pi to the AVR for the AVR to decode?

Both are valid approaches for non-Atmos content, and the 'decode to PCM' is the only approach for the Pi 3B+ and below for Dolby True HD and DTS HD MA (which the Pi traditionally can't bitstream *), whereas the Pi can bitstream/passthrough DD and DTS. It seems some have reported success with DD+ bitstream/passthrough.

(*) The Pi 4B supports 8 channel 192kHz over HDMI which means it should allow HD Audio passthrough (the previous generation of Pis only had enough bandwidth for 4 channel 192kHz so couldn't)

**mglae** · June 30, 2019 at 9:29 AM

Code

<setting id="audiooutput.eac3passthrough" default="true">false</setting>

I have no knowledge about possible hardware/software limitations of the RPI but EAC3/DD+ passthrough is disabled in your configuration.

novalis · June 30, 2019 at 9:43 AM

Quote from noggin

I think Da Flex is talking about getting the Raspberry Pi to decode DD+ to PCM in the Pi, whereas Novalis wants passthrough/bitstreaming, where the DD+ bitstream is passed, untouched, from the Pi to the AVR for the AVR to decode?

Yes, you got it.

Both are valid approaches for non-Atmos content, and the 'decode to PCM' is the only approach for the Pi 3B+ and below for Dolby True HD and DTS HD MA (which the Pi traditionally can't bitstream *), whereas the Pi can bitstream/passthrough DD and DTS. It seems some have reported success with DD+ bitstream/passthrough.

Well that was the clarifying I was hoping for. Although, as you said, some have reported otherwise for DD+. Like trent here in this thread. So....

(*) The Pi 4B supports 8 channel 192kHz over HDMI which means it should allow HD Audio passthrough (the previous generation of Pis only had enough bandwidth for 4 channel 192kHz so couldn't)

Well yeah, have allready ordered one, so why should we be bothered with the 3B

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How can I break up a citation?

novalis · June 30, 2019 at 9:46 AM

Quote from mglae
Code
<setting id="audiooutput.eac3passthrough" default="true">false</setting>
I have no knowledge about possible hardware/software limitations of the RPI but EAC3/DD+ passthrough is disabled in your configuration.

Yes, very sharp. The reason is to be found in the title of this topic.

This is the center of the problem.

Enable it - nothing.

Disable it - PCM

novalis · June 30, 2019 at 9:49 AM

Quote from Da Flex

Do you have DD+ audio with the suggested default values on Netflix?

We can talk about sense and details later.

Audio is working, so no idea what you mean by DD+ default values...