[daharn]

Hello. This is my (test-)setup:

Raspberry Pi 2 with additional HiFiBerry Digi+ -board (see here) for optical/coaxial digital audio output
OpenElec 6.0 which comes with Kodi 15.2 Isengard
Sony KDL-40Z5800 tv, connected via HDMI, can decode Dolby Digital only
Samsung HW-D 450 soundbar, connected via optical S/PDIF, can decode Dolby Digital and DTS

The decoding capabilities of the devices have been tested and confirmed via laptop.

What happens?

When I enable passthrough in Kodi's audio settings (and "AC3/DTS-capable receiver" respectively), I don't get any sound through the soundbar, no matter what Codec the source is and I only get static hissing through the TV (which is expected for anything BUT DD, but DD also gives out just hissing).

What have I tried already?

I tried with the newest OpenElec betas coming with Kodi 16 or 17 to no avail.

BUT using OpenElec 5.0.1 (and possibly also 5.0.8) coming with Kodi 14.1 enables me to passthrough DTS to the soundbar. DD, however, still not working. (Also, my wifi stick is not recognized, so this is not really an option)

Logfiles:

This is a log from an attempt to play DD and DTS via optical output to the soundbar with passthrough enabled:
log S/PDIF

This is a log from an attempt to play DD via HDMI to the TV with passthrough enabled:
log HDMI


Anybody got any ideas? I am aware that passthrough seems to be a rather fickle thing with Kodi and RasPi.

[popcornmix]

Can you try enabling omxplayer in video/acceleration settings?

[daharn]

I will try, but according to the wiki this won't work with ALSA which is used by the Digital audio out.

[popcornmix]

omxplayer might help the DD via HDMI case, but you are right, it won't work with HifiBerry.

[daharn]

I have tested it now:

With omxplayer enabled and MMAL disabled, I get indeed an audio signal for DD via HDMI. But as expected, HifiBerry won't work and my simple DD testfile will only deliver audio but no video signal. I assume, this is because it's a .vob file. My DD+ file, which is mkv, runs fine and audio is passed to the TV in both cases.

Any other combination of omx and MMAL results in the original problems.

Any other suggestions besides switching to full internal decoding?

EDIT: I mean, losing the ability to passthrough DTS from 5.0.1 to 6 for me seems to be a regression, or is there another reason?

[daharn]

Sorry if I seem impatient, but this really bothers me.

I can now confirm that the last version with working DTS passthrough for me is 5.0.8. Dolby passthrough never worked for me.

However, according to this thread (in which I have also posted) it was working for someone: http://openelec.tv/forum/124-raspberry-p...dts#155371

So, repeating my last question form there: Regarding this drop of DTS passthrough, can you tell me who best to address with this regression?

And sorry for the crossposting, but I still don't know whether this an OpenElec or Kodi related problem.

[dkscan]

It's an unresolved Kodi problem reported long ago: http://trac.kodi.tv/ticket/15825

[daharn]

Thanks for the reply, I have stumbled upon the Sony TV related discussion before and this might indeed be a factor.
However, by now I have also tested it with an (older) LG TV, getting the same noise.
And since it is also not working via ALSA S/PDIF (although without any noise then, so might be a different issue) I figured it to be a more general kodi/dvdplayer issue.

[popcornmix]

Thanks for the reply, I have stumbled upon the Sony TV related discussion before and this might indeed be a factor.
However, by now I have also tested it with an (older) LG TV, getting the same noise.
And since it is also not working via ALSA S/PDIF (although without any noise then, so might be a different issue) I figured it to be a more general kodi/dvdplayer issue.

They latest test is through HDMI?
Are you testing AC3 or DTS passthrough?
What is the make/model of the TV?
Have you tried with omxplayer enable/disabled?

[dukester]

i installed the 0112 ,13 ,14 nightlies and they all showed the same for me, no Dolby Digial output or DTS over HDMI with videoplayer, i just keep mmal unchecked now as i havent found anything that really benefits using it yet, except hevc, which i only have and 1080p files around 1.5mbs and they play but horribly on the pi2 for me.

[popcornmix]

i installed the 0112 ,13 ,14 nightlies and they all showed the same for me, no Dolby Digial output or DTS over HDMI with videoplayer, i just keep mmal unchecked now as i havent found anything that really benefits using it yet, except hevc, which i only have and 1080p files around 1.5mbs and they play but horribly on the pi2 for me.

On nightlies, passthrough is only supported when "sync playback to display" is disabled and you are not playing live content (including PVR).

[dukester]

i installed the 0112 ,13 ,14 nightlies and they all showed the same for me, no Dolby Digial output or DTS over HDMI with videoplayer, i just keep mmal unchecked now as i havent found anything that really benefits using it yet, except hevc, which i only have and 1080p files around 1.5mbs and they play but horribly on the pi2 for me.

On nightlies, passthrough is only supported when "sync playback to display" is disabled and you are not playing live content (including PVR).

thank you, i thought that setting was needed for proper playback, so should i be using using both video player options on or just mmal or omx?

[popcornmix]

thank you, i thought that setting was needed for proper playback, so should i be using using both video player options on or just mmal or omx?

Those restrictions on passthrough only apply to videoplayer/mmal - not to omxplayer.
Disabling "sync playback to display" may make video more stuttery with videoplayer/mmal.
I think you can enable AC3 transcode to get multichannel passthrough and still have sync playback to display or live streams (although with a theoretical loss of audio quality).

[daharn]

Thanks for the reply, I have stumbled upon the Sony TV related discussion before and this might indeed be a factor.
However, by now I have also tested it with an (older) LG TV, getting the same noise.
And since it is also not working via ALSA S/PDIF (although without any noise then, so might be a different issue) I figured it to be a more general kodi/dvdplayer issue.

They latest test is through HDMI?
Are you testing AC3 or DTS passthrough?
What is the make/model of the TV?
Have you tried with omxplayer enable/disabled?

Yes it was through HDMI. I tested both, although I did not expect the TV (47LG5000) to be able to decode dts in the first place. Result was the same for both, anyway, static noise.
Switching MMAL for omxplayer I haven't tried this time, but as written above this already solved most of the problem at my own Sony TV, so it's probably save to assume it would have done the same in this case. The problem most certainly lies with MMAL/videoplayer. And I can't ditch it if I want to use my soundbar via S/PDIF. Although an hdmi splitter would most likely be a possible workaround.

EDIT: Just tested another device, a Philips cineos TV. Here, Dolby digital passthrough is working via HDMI. This makes me believe that problems via HDMI are most likely device related.

[daharn]

Still searching the reason while SPDIF passthrough is not working, I found this patchlog by you saying:

Code:

This adds a dedicated subdevice which can be used for passthrough of non-audio
formats (ie encoded a52) through the hdmi audio link. In addition to this
driver extension an appropriate card config is required to make alsa-lib
support the AES parameters for this device.

Could you elaborate what kind of config you mean by this?