[newtonthecat]

I have a strange problem and no matter how much searching I cannot find any reports of the same problem or indeed a solution. I usually pride myself in being able to self troubleshoot and find solutions on the web but this time I am stumped. Hopefully the community can help.

I have Kodi 15 or 16 (beta) on RPI (Openelec) playing MKVs with DTS 5.1 audio directly into my AV AMP via HDMI, DTS works perfectly meaning that my Kodi box is set up to pass through DTS.

If I connect the same box to my LG WebOs 2.0 TV (2015 model) the TV does not get DTS, it changes to PCM. Dolby Digital 5.1 works fine though.

My TV supports DTS and to prove it I connected my old WD TV box and played the same MKVs direct into the TV via HDMI and the TV picked up the DTS audio. I also tried my XBOX One with a DTS source and the TV got the DTS from that as well.

I also tried the same MKVs on Kodi 15 on Amazon Fire TV box. Same result - FireTV -> AV AMP, DTS Works! FireTV -> LG TV, DTS does NOT work. Again, DD AC3 5.1 works OK.

So it looks like there is something to do with the DTS signal from Kodi that my AV AMP (Denon AVR-2307) likes but my TV does not.

Just to repeat, because I know there is plenty of information out there about LG (and other brands) accepting, or not, DTS audio. My TV does accept DTS audio from external devices like my WD TV and XBOX One and outputs the multi-channel stream (DTS or DD 5.1) via the TV's digital audio output (optical).

In case anyone is interested in why I am trying to do this it is because I want to have my devices connected directly to the TV and then use the digital audio out to feed the sound back to my AMP instead of feeding the devices into the AMP as it only has 2 HDMI inputs and I also want to set the TV to different picture settings depending on the device.

[DaVu]

Maybe you should Name the exact model of your TV. It might help.

As a wild guess, I would say, that the other devices did some changes internally before the TV gets the signal. So if you connect your Kodi to your TV I would just disable anything DTS capable receiver related and you will get sound.

While Kodi is in passthrough mode, the signal isn't touched in any way. So Kodi does absolutely nothing to the signal.

[newtonthecat]

Maybe you should Name the exact model of your TV. It might help.

Thanks for replying David. The TV model is 55LF652V Which I believe is European version of the 55LF650V, a part of the 2015 LF6500 range.

disable anything DTS capable receiver related and you will get sound.

When I do that, I do get sound but it is only PCM.

When I enable pass-through and DD + DTS capable receivers I get DD and DTS when connected directly to my Denon AMP so that is working, it just isn't working when connected to the TV. However playing the same MKV files from another device (e.g. WD TV) directly into the TV the DTS works. It doesn't appear to be specific to the RPI as I have the same situation with Kodi on FireTV (DTS works when connected direct to the AMP but not the TV). I'm pretty sure I have tried every possible combination of options in Kodi System Settings.

[DaVu]

can we get a screenshot from your audio settings and maybe a Debug Log while playing a DTS file?

[popcornmix]

Your TV almost certainly doesn't support DTS passthrough. Very few TV's do.
Note: Supporting DTS decode from TV's internal player is very different from supporting DTS passthough from an external device.
The two features require different licensing and having the first supported does not mean the second is supported.

[newtonthecat]

Note: Supporting DTS decode from TV's internal player is very different from supporting DTS passthough from an external device.

But if I plug my WD TV media player box into the TV via HDMI and with it's audio settings set to "Digital pass-through via HDMI" and play one of my DTS MKV's it plays fine and the TV 'sees' the DTS audio and outputs it in multi channel via the optical out. Is that a different kind off 'pass-through' ?

I will see if I can grab a Kodi log file while playing DTS later on.

[DaVu]

What I still guess is, your WD doesn't support DTS. Which model is it?

Have you ever plugged the WD TV directly to the amp and if yes, does the amp show DTS in the display while you trying to play back a DTS file?

Not all WD TV media players support DTS audio. See here: http://support.wdc.com/KnowledgeBase/ans...px?ID=3590

So I guess, your TV gets something else and pass this to the amp in multichannel.

Kodi itself is capable of DTS and if you selected DTS capable receiver it won't do anything to the signal. So TV receives DTS and this maybe cannot be passthroughed to the amp. If you disable "DTS capable receiver" the TV might get what it is capable off and you will get multichannel at the amp again.

But it's just guessing.

[newtonthecat]

I am using WD TV just to make sure the TV is happy with the MKV files I am throwing at it and when it receives a DTS signal via HDMI it sees it and outputs it to the TV's optical digital audio out.

Right, here goes, for clarification!

WD TV Supports DTS. Audio settings set to pass-through digital audio to HDMI.
WD TV connected to AMP via HDMI. Amp shows multi channel DTS signal being received and all is good.
WD TV connected to TV via HDMI. TV shows DTS audio signal being received and outputs DTS to AMP via optical output. AMP shows DTS signal, all channels working. All is good.

Kodi (RPi or FireTV). Audio settings set to pass-through and DD + DTS capable receiver
Kodi (RPi or FireTV) connected to AMP via HDMI. Amp shows multi channel DTS signal being received and all is good.
Kodi (RPi or FireTV) connected to TV via HDMI. TV does *not* show DTS is being received (shows PCM) and thus, the output via optical out is not DTS.

For reference, Kodi connected to TV playing Dolby Digital 5.1 MKV works fine. TV sees Dolby Digital and outputs 5.1 via digital audio out to the AMP.

So all I can conclude at the moment is that the pass-through signal that Kodi is sending is different to the pass-through signal that WD TV is sending. But as you say, DTS enabled pass through is 'supposed' to do nothing to the signal.

On a side note I have emailed LG a couple of days ago and they have confirmed that this TV fully supports DTS output on optical-out as long as the input device (connected by HDMI) is sending a DTS signal (duh!)

[popcornmix]

Do you hear (stereo) audio when DTS passthough is enabled and you connect to TV?
If you do then I suspect DTS passthrough is not enabled.

Note: The Milhouse builds use VideoPlayer which disables passthrough when "sync playback to display" is enabled.
Either enable omxplayer or disable "sync playback to display" for testing (or test with official Kodi 15).

[newtonthecat]

No, I don't hear audio on the TV from Kodi when DTS passthrough is enabled.

But when I plug Kodi (FireTV or RPi) into the AMP directly, without changing any settings, I get full DTS suggesting that the passthrough setting is enabled and working.

I did see the option in video playback on Kodi 16 for "sync playback to display" and I had disabled it. I have been trying with both official Kodi 15.2 and 16.

It's a shame this isn't working because I felt quite pleased that my new TV was one of the few TVs that can passthrough DTS to it's optical digital audio out from an external source connected via HDMI but perhaps it's still a bit dependent on the device. Works flawlessly with my XBOX One and WD TV, the latter being somewhat redundant though as it was just for testing the functionality.

I appreciate the effort you've made to help troubleshoot this. Perhaps it just needs time before other people with similar TVs can discover the same problem and dig a bit deeper.

I will try and do a Kodi log though, once I work out how to do that (I'll check the link David posted above)!

[newtonthecat]

OK, Some sort of good news.

On Kodi 16 on RPi I found another option in Settings->Video->Acceleration

"Allow hardware acceleration - MMAL" was selected and OMXPlayer was disabled.

I changed this so OMXPlayer was enabled and MMAL was disabled and DTS through the TV then worked!

(audio output was still set to pass-through with DTS enabled)

OMXPlayer does not appear to be an option on Kodi 15.2 on FireTV. So I need to see if it will be an option on Kodi 16 on Fire TV or if it is just not an option on Android/FireTV.

Anyway, some progress at least.

[Memphiz]

instead you could disable dts pass through in kodi and enable ac3 transcode instead (dts will be transcoded to ac3 then)

[DaVu]

Disabling DTS capable receiver (which is disabling DTS passthrough then) was the first thing I mentioned in the 2nd post of this thread

[Memphiz]

is there no ac3 transcoding setting appearing when you disable dts? (maybe it is not available on the pi)

Set speakerlayout in kodi to 2.0 - disable dts and you should see an option to enable ac3 transcode.

[newtonthecat]

AC3 transcoding appears as an option under Dolby Digital capable receiver on RPi. When I check it and disable DTS capable receiver it doesn't work.

EDIT: I must have missed something. Disabling DTS capable receiver and enabling AC3 transcoding did work on Kodi on Fire TV. The DTS MKV audio was converted to Dolby Digital 5.1 and the TV saw it as DD and output it to the TVs optical audio output OK.

For real DTS it looks like OMXPlayer hardware acceleration on RPi solves the problem but OMXPlayer does not appear to be available on the Android/FireTV Kodi.

I had another RPi (1st Gen) with an old Kodi Helix on it. I tried that with OMXPlayer hardware acceleration ant that worked too. My TV saw the DTS signal and output it in full to the TVs optical audio output.

At least that confirms that there is nothing wrong with my setup and the problem is the pass-through DTS stream coming from Kodi on Android.

It is still very odd that the DTS signal from Kodi on Android works fine going straight into my AV AMP but not the TV.

It suggests that the pass-through audio stream for a DTS MKV is different using OMXPlayer hardware acceleration.

In summary, as it stands:

DTS pass-through for Kodi on FireTV works with AV Amps but not DTS-enabled LG TVs.
DTS pass-through for Kodi on RPi (openelec) works with AV Amps AND DTS-enabled LG TVs as long as OMXPlayer is used for video hardware acceleration.