No audio intermittently using passthrough HDMI

using odroid n2+, denon x3600h, passthrough hdmi. Passthrough is set to HDMI, as is audio output device. All codecs are ticked as the denon can handle them all.

Having intermittent audio issues where I get no audio. When this issue occurs, the receiver doesn’t change to the correct codec on the AVR screen (it remains as what the codec is on the kodi menu). The tv show in question is DD+.

Attached are some debug logs - I repeatedly played episodes one to eight of the same tv show, and the logs are named for which episode it failed on. On the log that failed on e07, it failed on the second attempt of playing it, as it went through e01 to e08 without failing the first time.

I am very keen to fix it as it is pretty annoying. Hoping someone can see what is failing in the logs. I can say that using kodi running from my computer (still via the AVR etc) I never have any of these issues.

kodi.failed.e01.log (1.1 MB)
kodi.failed.e02.log (1.3 MB)
kodi.failed.e04.log (753.7 KB)
kodi.failed.e04-2.log (1.1 MB)
kodi.failed.e07.log (1.8 MB)

Try to play problematic content.
Post Kodi log and dmesg log (run dmesg | paste in SSH and copy the URL)
Upload a sample of problematic content.

Tried playing something, it failed first attempt.
kodi.log (755.8 KB)

Tried your sample on my N2, and there is no audio with Passthrough enabled. With disabled it plays in standard AC3_5.1 format.
My guess is that I have no audio with passthrough enabled due to a “weird” audio format/codec used; there are 2 side channels mixed into standard ac3_5.1 format, and my receiver does not know how to handle that. After remuxing audio to standard ac3 format, passthrough works OK.

Sometimes I can play it 10 or more times in a row and it plays every time (always passthrough).
But sometimes, different shows (with various codecs) do not give audio. I stop it, try again, etc. It always plays eventually, I’ve never had to anything to the audio stream to get it to work.

But it’s not ideal as it is at the moment. It can happen with almost any tv show.

still happening all the time
had a show last night that played on the 4th attempt.

Can you see anything in the info I provided?

I’ve seen this with a very similar set up (N2 → Denon X2700h). I can’t recall if this was also with Aus. broadcast stuff (probably was) but was also with some movies at times etc.

Happens just enough that I instead get Kodi to decode and send multi channel PCM. The net result is the same as passthrough, but Kodi is more tolerant of wierdo files. With the modern Denons all the audio processing magic works just as well with incoming PCM as audio so there’s no practical disadvantage that I can see (and zero impact with the N2s performance, it can handle this sort of thing trivially it seems).

It’s definitely N2/N2+ related, as it doesn’t happen on an old MeCool device, nor when connected to Kodi running on a PC.

Possibly… They PC would be a very different scenario of course.

Is the Mecool running CE?

hmm actually I just checked, Libreelec.

Real shame I can’t get the N2+ working as it should, a real pain. Not that cheap either… paid aussie prices to get it as well :wink: I would really like to know what the problem is.

The PCM approach works perfectly and is identical to bit streaming…

That is not accurate. It depends on what you’re trying to bitstream.
Specifically, you will not be able to do that with Dolby Atmos or DTS:X formats.

Ah that’s definitely a good point. But not an issue for me, 5.1 here.

(Personally I’d rather have excellent 5.1 than 11.2 crappy speakers … which is where most Atmos installations seem to to end up in practice!)

Well, looks like we aren’t getting any more replies.

For those reading later, there is no solution, only the workaround of not passing through certain codecs (in my case, the issue only seems to occur on DD and DD+), and using the Multi PCM approach for those.

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