Do some hardware handle Audio passthrough better than others?

pwntato · October 5, 2018 at 12:29 PM

Hi!

I recently swapped my Odroid (running CoreELEC) for an Intel NUC6CAYH running LibreELEC latest Krypton. Overall a big upgrade except for a thing that raises some questions.

With the Nuc I need to set a 735ms delay for 24p video in advancedsetting to have my movies a/v synced when using audio passthrough. In combination with setting the screen refreshrate to match the media being played that is.

With that said. Is this a hardware specific issue or is it a LibreELEC vs CoreELEC thing? If I were to guess i'd say it's a S905 perk compared to Intel, but I actually have no idea.

I guess I'm just curious if I can look forward for this being fixed or not It's hard to get the perfect delay setting.

Also I have to use the passthrough and DTS transcoding to get surround, since I'm using a Sonos playbar setup. I mean it's a great feature

Any knowledge out there?

**chewitt** · October 6, 2018 at 5:14 AM Official Post

Are you routing HDMI through something? .. 735ms is a HUGE delay to incur somewhere in the processing chain

pwntato · October 6, 2018 at 6:20 AM

Nope! Hdmi between Nuc and TV. And the problem only occurs when the TV sets it self to 24p.

**chewitt** · October 6, 2018 at 6:28 AM Official Post

I've only ever seen delays on the audio side from processing (requiring video to be retarded, or in kodi-speak the audio to be advanced) never video delays that require a corresponding audio delay. Weird. What TV panel?

pwntato · October 6, 2018 at 6:36 AM

Oh. Its a bit confusing. In my case i have advance the audio. In advancedsettings i put a video delay to match the audio since I cant find a way to set audio +/- minus in the xml file.

I use a 60" led from Samsung. Nothing fancy. ju6075 i believe its called

**chewitt** · October 6, 2018 at 6:52 AM Official Post

If you need to delay video to match the slower audio path that makes sense. I'd guess you have HDMI to the TV which has to process the audio to an optical or HDMI output on the TV and from there into the Sonos which then has to process the audio for output. Even if everything is in pass-through audio mode the format might not change but there's still going to be a buffered input/output process somewhere, and that's where delays stack up.

pwntato · October 6, 2018 at 7:36 AM

But it works flawless except for when the display is in 24p. And no problems when I used the Odroid. Thats the thing im trying to narrow down. If its a hardware problem or not

pwntato · October 6, 2018 at 1:19 PM

Hmm. Thats weird. Seems to be working now. For future reference, I missed to check "Output configuration" to Best match. I had it set to optimized. I dont know why it makes any difference. But it clearly does.