6ch audio over HDMI audio trouble

Anke · October 3, 2020 at 10:00 PM

Pi 3 Model B , hardware code a02082

LibreELEC (official): 9.2.4 (RPi2.arm)

If I enable HDMI 5.1 audio, i will have trouble with center channel, and/or other channels, only in movies with 6channels. - apparently regardless of codec.

Enabling HDMI 2.0 or 2.1 works flawlessly

If I were to buy an onboard SPDIF/Toslink board like:: Raspberry Pi 3 Model B HIFI DiGi Digital Sound Card I2S SPDIF Expansion Board Digital Chip for Raspberry Pi 2|chip board|chip cardchip sound - AliExpress : will it "just work" with this distro ?

**Da Flex** · October 5, 2020 at 2:44 AM Official Post

We have similar reports from other RPi users, so I think it's a bug. Enable pass-through at the audio settings and try again. That expansion board will not fix the bug.

Anke · October 6, 2020 at 8:46 PM

I did try pass-thru - have no reason to believe it was requires, did not reboot - but the issue remained.

**Da Flex** · October 7, 2020 at 5:17 PM Official Post

Please describe the media formats you use (codec, file format, streaming provider). We're still stepping in the dark here.

PS: Codec Info

**Da Flex** · October 12, 2020 at 12:41 AM Official Post

You talk about HDMI 5.1 audio. This doesn't exist, but now I have the idea that you eventually use an HDMI audio extractor with an 5.1 / 2.1 channel switch. Am I correct? A user at this thread currently has trouble with such an extractor.

If yes, then your described sound expansion board could work.

openbaffle · October 15, 2020 at 2:06 PM

Quote from Da Flex

You talk about HDMI 5.1 audio. This doesn't exist, but now I have the idea that you eventually use an HDMI audio extractor with an 5.1 / 2.1 channel switch. Am I correct? A user at this thread currently has trouble with such an extractor.

If yes, then your described sound expansion board could work.

I have used the below product for both raspberry and intel/amd as source, and tv/projector as display, with custom made class d amplifiers. only problem is if you don't have multichannel HDMI preamp control, we need to depend on the keyboard volume control, which I found to be little garbage sound.

hdmi extractor multichannel

this co is oem for some good extractors cyp

Anke · October 21, 2020 at 7:59 PM

Sorry for the late response, will check where the expected email-notifications went, if they are sent.

I am using a HDMI->TOSLINK/SPDIF extractor. The reason thatI requested whatever the TOSLINK device I ordered will work, is because HDMI audio is played through the projector as well.

you wrote: "You talk about HDMI 5.1 audio. This doesn't exist,"

Yes, on Rpi, when I select HDMI out, I can select channels: 5.1 - and - I enabled passthru, and played a THX test video (VOB from DVD), that worked just fine. (heard all 6 channels just fine)

Then I tested two movies with AAC5.1 audio, missing voice channel, or barely audible. (I doubt AAC is passed through, but decoded/poorly before being sent.)

Switching output to 2.1 "works".

**Da Flex** · October 21, 2020 at 8:59 PM Official Post

OK, looks like AAC codec is the problem. Another user made an interesting point: He changed the HDMI mode to make it work - click.

PS: I just mean that HDMI 5.1 / 2.1 / 2.0 audio is no official standard.

Anke · October 21, 2020 at 9:24 PM

Thank you.

Great, so now I can workaround by dropping to 24FPS, ...and get an "very freezing" interface.. I love choices

Seriously: should I get some other hardware instead? - maybe a weak x86 thingy ? I had problems with h265 too, and start to suspect RPi is not the way to go.

**Da Flex** · October 21, 2020 at 11:25 PM Official Post

Yes, reducing video quality to increase audio quality points to a weak data bus. That's why your above RPi sound card will not do the trick.

If you search for best audio compatibility (Dolby Atmos etc.), and price doesn't matters, then have a look at the Nvidia Shield TV. It's probably the best streaming box (also available as "pro" version).

If you want to stay with LE, an Intel NUC will provide better performance. I don't have this, so other users should verify AAC / H265 compatibility before you buy.

Anke · October 22, 2020 at 3:39 PM

(email notifications are off by default for new users, that explains my initial slow response.)

Thank you.

I agree, the RPi SPDIF/TOSLINK card was mainly supposed to workaround the need for audio extraction, and that the projector gets sound. (It always defaults to unmuted)

So I completely agree that the soundcard won't solve the performance issue.

I have another issue as well:

Norwegian censorship stops DNS resolving of opensubtitles.org

kodi's SOCKS5 with DNS is not supported by PriveteInternetAccess (aka PIA) that I use. (not the DNS part)

nor does PIA support RPi .. their (rather nice) Linux client is great on Ubuntu - so that could indicate that I really should just use a weak (not-noisy) SFF computer or something like that for the job.

**Da Flex** · October 22, 2020 at 7:48 PM Official Post

Quote from Anke

I have another issue as well:

Norwegian censorship stops DNS resolving of opensubtitles.org

kodi's SOCKS5 with DNS is not supported by PriveteInternetAccess (aka PIA) that I use. (not the DNS part)

nor does PIA support RPi .. their (rather nice) Linux client is great on Ubuntu - so that could indicate that I really should just use a weak (not-noisy) SFF computer or something like that for the job.

Please open a new thread for this question.

I close this one to make it not too messy.

6ch audio over HDMI audio trouble

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