Kodi Community Forum - Libreelec, e-ac3 5.1 Dolby Digital Plus passthrough

Hi All,

I'm hoping someone can help me here, as I have tried everything I can think of.

Issue -
I cannot seem to get Dolby Digital Plus within an e-ac3 stream to pass through to my surround setup.
When playing a file with e-ac3, I hear zero audio at all; nothing comes through, and the soundbar reports the sound as LPCM.

My setup -
I have a Raspberry Pi 3 running LibreElec 9.0.1 (Leia 18.1), the Pi is connected to a Sony X95G TV (brand new model) via HDMI.
The TV is then connected to a Sony HT-Z9RF surround setup via eARC.

TV has been configured to have audo mode as eARC, and also have the Dolby Digial Plus output set to "Dolby Digital Plus".

I've tried -
It seems that no configuration on the Pi from the Kodi audio quickstart guide will allow it to pass through DD+, however having a configuration to 2 channels with "Dolby Digital (AC3) Transcoding" enabled and "Dolby Digital Plus (E-AC3) capable receiver" disabled does pass through normal (transcoded) Dolby Digital.

I have also (on a secondary Pi 2) installed OSMC and attempted all the configurations above with the same results.

On a Windows 10 PC (connected via the same means; HDMI to the TV, followed by eARC from the TV to soundbar) - playing the same e-ac3 file via VLC seems to pass through DD+ fine (I did have to enable a pass through setting within VLC).

I have enabled debug logging, and uploaded the file for review.

I feel like I'm doing something monumentally stupid as there are plenty of threads I've found where people appear to have got it working through some variation of settings..

Any help would be greatly appreciated Smile

Also first post so apologies for any mistakes

Not sure if your mention of ‘2 channels’ was part of your trial-and-error troubleshooting or your normal set up, but you’ll need ‘number of channels’ set to 7.1.

For what it’s worth, my userdata/guisettings.xml file on OSMC (which can successfully pass DD+ to my amp) contains the following:

Code:
    <audiooutput>

        <ac3passthrough default="true">true</ac3passthrough>

        <ac3transcode default="true">false</ac3transcode>

        <atempothreshold default="true">2</atempothreshold>

        <audiodevice default="true">PI:HDMI</audiodevice>

        <boostcenter default="true">0</boostcenter>

        <channels>10</channels>

        <config default="true">2</config>

        <dspaddonsenabled default="true">false</dspaddonsenabled>

        <dtshdpassthrough default="true">false</dtshdpassthrough>

        <dtspassthrough>true</dtspassthrough>

        <eac3passthrough>true</eac3passthrough>

        <guisoundmode default="true">1</guisoundmode>

        <maintainoriginalvolume default="true">true</maintainoriginalvolume>

        <mixlfe default="true">0</mixlfe>

        <passthrough>true</passthrough>

        <passthroughdevice default="true">PI:HDMI</passthroughdevice>

        <plladjust default="true">0</plladjust>

        <processquality default="true">30</processquality>

        <samplerate default="true">48000</samplerate>

        <stereoupmix default="true">false</stereoupmix>

        <streamnoise default="true">true</streamnoise>

        <streamsilence default="true">1</streamsilence>

        <truehdpassthrough default="true">false</truehdpassthrough>

        <volumesteps default="true">90</volumesteps>

    </audiooutput>

Not suggesting you edit the file directly (it’s safer to configure things through the GUI) but it might be worth comparing with your own file for inspiration. Also - not sure why my ‘channels’ show as 10 rather than 7.1; that probably underlines my point about using the GUI rather than a text editor!

(2019-06-23, 11:01)Fergus Wrote: [ -> ]Not sure if your mention of ‘2 channels’ was part of your trial-and-error troubleshooting or your normal set up, but you’ll need ‘number of channels’ set to 7.1.

For what it’s worth, my userdata/guisettings.xml file on OSMC (which can successfully pass DD+ to my amp) contains the following:

Code:
<audiooutput> <ac3passthrough default="true">true</ac3passthrough> <ac3transcode default="true">false</ac3transcode> <atempothreshold default="true">2</atempothreshold> <audiodevice default="true">PI:HDMI</audiodevice> <boostcenter default="true">0</boostcenter> <channels>10</channels> <config default="true">2</config> <dspaddonsenabled default="true">false</dspaddonsenabled> <dtshdpassthrough default="true">false</dtshdpassthrough> <dtspassthrough>true</dtspassthrough> <eac3passthrough>true</eac3passthrough> <guisoundmode default="true">1</guisoundmode> <maintainoriginalvolume default="true">true</maintainoriginalvolume> <mixlfe default="true">0</mixlfe> <passthrough>true</passthrough> <passthroughdevice default="true">PI:HDMI</passthroughdevice> <plladjust default="true">0</plladjust> <processquality default="true">30</processquality> <samplerate default="true">48000</samplerate> <stereoupmix default="true">false</stereoupmix> <streamnoise default="true">true</streamnoise> <streamsilence default="true">1</streamsilence> <truehdpassthrough default="true">false</truehdpassthrough> <volumesteps default="true">90</volumesteps> </audiooutput>

Not suggesting you edit the file directly (it’s safer to configure things through the GUI) but it might be worth comparing with your own file for inspiration. Also - not sure why my ‘channels’ show as 10 rather than 7.1; that probably underlines my point about using the GUI rather than a text editor!

The two channels was part of the investigation - I generally have it set to 5.1 as that's what my speaker configuration says it is.
Will give these settings a try tonight, and do a file comparison - thanks for your help.

(2019-06-24, 01:38)popsikill Wrote: [ -> ]
(2019-06-23, 11:01)Fergus Wrote: [ -> ]Not sure if your mention of ‘2 channels’ was part of your trial-and-error troubleshooting or your normal set up, but you’ll need ‘number of channels’ set to 7.1.

For what it’s worth, my userdata/guisettings.xml file on OSMC (which can successfully pass DD+ to my amp) contains the following:

Code:
<audiooutput> <ac3passthrough default="true">true</ac3passthrough> <ac3transcode default="true">false</ac3transcode> <atempothreshold default="true">2</atempothreshold> <audiodevice default="true">PI:HDMI</audiodevice> <boostcenter default="true">0</boostcenter> <channels>10</channels> <config default="true">2</config> <dspaddonsenabled default="true">false</dspaddonsenabled> <dtshdpassthrough default="true">false</dtshdpassthrough> <dtspassthrough>true</dtspassthrough> <eac3passthrough>true</eac3passthrough> <guisoundmode default="true">1</guisoundmode> <maintainoriginalvolume default="true">true</maintainoriginalvolume> <mixlfe default="true">0</mixlfe> <passthrough>true</passthrough> <passthroughdevice default="true">PI:HDMI</passthroughdevice> <plladjust default="true">0</plladjust> <processquality default="true">30</processquality> <samplerate default="true">48000</samplerate> <stereoupmix default="true">false</stereoupmix> <streamnoise default="true">true</streamnoise> <streamsilence default="true">1</streamsilence> <truehdpassthrough default="true">false</truehdpassthrough> <volumesteps default="true">90</volumesteps> </audiooutput>

Not suggesting you edit the file directly (it’s safer to configure things through the GUI) but it might be worth comparing with your own file for inspiration. Also - not sure why my ‘channels’ show as 10 rather than 7.1; that probably underlines my point about using the GUI rather than a text editor!
The two channels was part of the investigation - I generally have it set to 5.1 as that's what my speaker configuration says it is.
Will give these settings a try tonight, and do a file comparison - thanks for your help.

Unfortunately no luck with the above configuration.
However have ordered myself a Raspberry Pi 4, may switch over to OSMC and keep playing with both.