[guitarwizard93]

I'm running Kodi on OpenELEC from a Raspberry Pi 2, which is outputting HDMI into a HDMI-Optical audio extractor. The extractor has three modes, pass through, stereo, and 5.1. I'm leaving it on 5.1. Stereo sources play absolutely fine, that's not a problem.

When I play a file which I know is in 5.1, I only get left and right channels come through my surround sound system, I get no centre (dialogue) coming through - fairly crucial to most TV shows - yet alone rear speakers and sub.

In System>Audio Output I have "number of channels" set to 5.1. If I select 2.0, I get a "full" stereo sound, but I want full surround so put it back to 5.1. I've tried selecting the "Enable passthrough" feature, but it simply stops my video playback altogether for some reason. Side note, when 5.1 is selected I also get no GUI sounds at all...

Does anyone have any amazing fixes for such a seemingly stupid problem?

Thanks!

[popcornmix]

Optical only supports two channel audio. However DTS and AC3 passthrough can be passed over two channels (as they are compressed).

So kodi *must* have number of channels set to "2.0". Make sure DTS and AC3 passthough are enabled.
I'm not sure what the switch does on the splitter (probably just changes the audio support reported in the EDID). Probably makes no difference, but I'd set it to pass through if that works.

[guitarwizard93]

Optical only supports two channel audio. However DTS and AC3 passthrough can be passed over two channels (as they are compressed).

So kodi *must* have number of channels set to "2.0". Make sure DTS and AC3 passthough are enabled.
I'm not sure what the switch does on the splitter (probably just changes the audio support reported in the EDID). Probably makes no difference, but I'd set it to pass through if that works.

So I've just set the number of channels to 2.0 and set DTS and AC3 to enabled. Tried the splitter on each of the three settings - no joy.

With passthrough enables, I get silence. With passthrough switched off, I get a full stereo sound. The strange part is that sometimes with passthrough enabled I get the GUI sounds, sometimes I don't.. what the hell is going on? :S

This is getting so infuriating I'm tempted to just leave it in stereo all the time :/

[SeVreN2013]

I'm running openELEC 5.95 and using a HDMI Audio Extractor with the switch set to "Passthrough"

Kodi settings are 5.1 Channel Output and "Passthrough" enabled ... and Dolby Digital (AC3) and DTS capable receiver enabled.

I have a 5.1 Dolby Digital and 5.1 DTS test file .... and i'm getting 5.1 [Front: L C R Side: L R LFE] sound perfectly fine via Optical Out (from the HDMI Audio Extractor)

This is the HDMI Audio Extractor i purchased (works great ... does not need any extra power either !)
http://www.aliexpress.com/item/Free-ship...57632.html

[noggin]

Could it be EDID?

EDID is where the display (your TV) tells your source (your Pi) what video and audio formats are supported. Many TVs will only accept PCM 2.0 - so their EDID data says only PCM 2.0 is supported. Audio extractors that offer 5.1 audio output should add DD/DTS EDID data to the TV's EDID data, so that the Pi knows to send DD/DTS as well as PCM 2.0. (I think they should also strip this or decode it to PCM 2.0 to feed to the TV)

I don't know if the Pi follows EDID for audio or not - but if it does, then it may need to be overridden to force DD/DTS to be output?

Guitar wizard, can you post a link to your audio extractor?

I'd imagine you'd need 2.0 channels and passthrough enabled on the Pi and 5.1 enabled on the audio extractor (I think 2.0 on the extractor sends "PCM 2.0 only" via EDID and outputs analogue and 2.0 SPDIF, 5.1 sends "PCM 2.0/DD/DTS" via EDID outputs SPDIF and disables analogue output, and Passthrough bypasses the audio extractor outputs entirely). I'd also make sure you reboot every time you change the audio setting on the extractor.

[guitarwizard93]

The audio extractor is the one in this link:

http://www.amazon.co.uk/dp/B017BH1D14/re...TE_3p_dp_1

Admittedly it's not the most expensive so it may be a piece of junk, but hopefully it works alright :S

The "pass" setting is odd, it still appears to send sound to both the surround amplifier and the TV whether or not it's in that mode. I can't tell any obvious change with the "pass" setting enabled.

[popcornmix]

Could it be EDID?

The Pi (and I believe all kodi platforms) ignores the EDID for audio support. There are just too many incorrect EDIDs out there (especially when you use devices like an HDMI splitter).
So If you ask for DTS passthrough you'll get it. It you ask for 5.1 PCM you'll get it. Doesn't matter when the device you are connecting to reports.

It might be interesting to run "tvservice -a" on the Pi with the splitter set to stereo, passthrough, and 5.1 and see if that switch does affect the EDID.
However I wouldn't expect Kodi's behaviour to change in the slightest.

[noggin]

The audio extractor is the one in this link:

http://www.amazon.co.uk/dp/B017BH1D14/re...TE_3p_dp_1

Admittedly it's not the most expensive so it may be a piece of junk, but hopefully it works alright :S

The "pass" setting is odd, it still appears to send sound to both the surround amplifier and the TV whether or not it's in that mode. I can't tell any obvious change with the "pass" setting enabled.

Can you check that link - doesn't seem to work for me.

[noggin]

Could it be EDID?

The Pi (and I believe all kodi platforms) ignores the EDID for audio support. There are just too many incorrect EDIDs out there (especially when you use devices like an HDMI splitter).
So If you ask for DTS passthrough you'll get it. It you ask for 5.1 PCM you'll get it. Doesn't matter when the device you are connecting to reports.

It might be interesting to run "tvservice -a" on the Pi with the splitter set to stereo, passthrough, and 5.1 and see if that switch does affect the EDID.
However I wouldn't expect Kodi's behaviour to change in the slightest.

Thanks - wasn't sure if Kodi ignored or didn't.

guitar wizard - have you tried the adaptor with another HDMI Dolby Digital source like a DVD or Blu-ray player? (Beware all but the newest Sky boxes, they are PCM 2.0 only via HDMI for some annoying reason...)

[guitarwizard93]

For some reason this daft website didn't email me that anyone had replied to my last post...

That link is dead for me too, which is weird, it wasn't when I first posted it

I'll try putting a bluray player through the splitter now. I want the splitter set to passthrough right? I'll try it with each different setting and see what happens and report back...

[guitarwizard93]

Can't be sure that our bluray player or tivo box puts out 5.1 through HDMI so those tests didn't work..

Now I'm back to the Pi, here's what I'm getting...

Audio splitter set to 5.1:

Pi Passthrough: Disabled
Pi Number of Channels: 5.1
RESULT: 5.1 sound, L & R speakers only (centre and back speakers missing)

Pi Passthrough: Enabled
Pi Number of Channels: 5.1
RESULT: GUI sound from L & R speakers, no audio from video playback

Pi Passthrough: Disabled
Pi Number of Channels: 2.0
RESULT: Full stereo sound from L & R speakers

Pi Passthrough: Enabled
Pi Number of Channels: 2.0
RESULT: GUI sound from L & R speakers, no audio from video playback

Audio splitter on "Pass" mode:

Pi Passthrough: Disabled
Pi Number of Channels: 5.1
RESULT: 5.1 sound, L & R speakers only (centre and back speakers missing)

Pi Passthrough: Enabled
Pi Number of Channels: 5.1
RESULT: GUI sound from L & R speakers, no audio from video playback

Pi Passthrough: Disabled
Pi Number of Channels: 2.0
RESULT: Full stereo sound through L & R speakers

Pi Passthrough: Enabled
Pi Number of Channels: 2.0
RESULT: GUI sound from L & R speakers, no audio from video playback

So obviously the settings of my audio splitter are doing jack s***, as the results are the same.

Any marvellous ideas for a potential fix? At this right I'm starting to think my splitter just doesn't output 5.1 and I need a new one..

What should the "optimum" settings be for this??

[popcornmix]

It might be interesting to run "tvservice -a" on the Pi with the splitter set to stereo, passthrough, and 5.1 and see if that switch does affect the EDID.

Try this. Might be safest to reboot after changing the switch position.

[guitarwizard93]

It might be interesting to run "tvservice -a" on the Pi with the splitter set to stereo, passthrough, and 5.1 and see if that switch does affect the EDID.

Try this. Might be safest to reboot after changing the switch position.

Apologies for sounding thick but.. how do you do that?

[popcornmix]

Apologies for sounding thick but.. how do you do that?

You need to ssh in then type in the command "tvservice -a" (without the quotes) and copy the output.

[noggin]

I'll try putting a bluray player through the splitter now. I want the splitter set to passthrough right? I'll try it with each different setting and see what happens and report back...

Think you want the extractor in 5.1 mode.