nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Elfving — Mon, 09 Dec 2024 09:16:24 GMT

[quote user="Pio_NSatou"]Does it mean that I can modify it with changing some config files?
[/quote]

No, I unfortunately mean you would have to make bigger changes. Though we do have a lot of documentation about the application available which would make this easier for you.

I had a quick talk with the relevant team about this, and it seems that the channel encoding is one problem (as one channel spends 30~33% CPU). But another though would be the input interface, as the i2s only support 2 channels. There's no easy way for nRF5340 to get 3 streams input.

If you are fine using BIS for this (broadcasting, not connected) then you could try using the nRF Auraconfig sample for this, which would be a bit easier regarding testing. That sample uses pre encoded LC3 files from an SD-card, so there is no strain on the CPU for encoding, and you can than use these files instead of an i2s input. Some investigation with a sniffer regarding the air timing to make sure this still works well might be necessary though.

Either way, there are some potential issues (like audio quality) that you'll have to consider how to address, like eg. lowering the quality of a certain audio channel.

At this point I would also consider using a second nRF5340, or alternatively the nRF54H20.

[quote user="Pio_NSatou"]

or Does it mean that you(Official member) need more detailed research and modifying the entire SDK, including files other than the config file?
If yes, what should I do for your efforts?

[/quote]

My job is helping you, I don't need any more coercion than that :)

Though it is a bit harder to help you in a situation like this when there are multiple potential issues. If we find a way around these problems, then I still might be a bit limited if it turns out that if we for instance need to (like you mentioned) modify the entire SDK. Though in general, if you need more help from us than what is provided, please contact your RSM about this, and he might be able to help out.

Regards,

Elfving

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Pio_NSatou — Mon, 09 Dec 2024 08:38:56 GMT

Mr.Elfving
Thank you for your replying.

[quote userid="103347" url="~/f/nordic-q-a/116645/nrf5340-audio-dk-i-want-to-set-to-audio-demo-to-3ch-sink/513784"]the SDK does not support this without some modifications unfortunately.[/quote]

Does it mean that I can modify it with changing some config files?
If yes, I will try some setting change.All I can do is try blindly.

or Does it mean that you(Official member) need more detailed research and modifying the entire SDK, including files other than the config file?
If yes, what should I do for your efforts?

Best Regards,
Pio_NSatou

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Elfving — Fri, 06 Dec 2024 09:26:04 GMT

[quote user="Pio_NSatou"]I set lile this.
nrf\applications\nrf5340_audio\tools\buildprog\nrf5340_audio_dk_devices.json
- source 1:"nrf5340_audio_dk_dev": "gateway","channel": "NA"
- sink 3:"nrf5340_audio_dk_dev": "headset","channel": "right" and "left" and "center"
build result is the error on "channel": "center".[/quote]

I see. So you haven't gotten it working yet, but you have the idea ready made there.

So there are a few hurdles in the way of getting this working, and you'll have to modify the sample a bit. The buildprog script for instance does not work with the "center" command. My suggestion earlier was to keep one stereo channel for left and right, and other one for center, so if you want to modify the Audio app sample to support this you need to make eg. the left support stereo, and let the other be the one for center.

So I can look into what would be needed to get this working, but the audio application we have in the SDK does not support this without some modifications unfortunately.

Regards,

Elfving

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Pio_NSatou — Fri, 06 Dec 2024 06:01:05 GMT

Mr.Evfving

Dou you know about them?
I hope you check my comment on 2024/12/4.

Pio_NSatou

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Pio_NSatou — Wed, 04 Dec 2024 01:00:42 GMT

Mr.Elfving
Thanks for the advice.

I'm using NCS ver2.8.0.
And I see the latest documentation.nRF5340 Audio applications

I set lile this.
nrf\applications\nrf5340_audio\tools\buildprog\nrf5340_audio_dk_devices.json
- source 1:"nrf5340_audio_dk_dev": "gateway","channel": "NA"
- sink 3:"nrf5340_audio_dk_dev": "headset","channel": "right" and "left" and "center"
build result is the error on "channel": "center".

And yesterday, I tyied like this.
nrf\applications\nrf5340_audio\unicast_client\Kconfig.defaults
- config BT_MAX_CONN default 2->3
- config BT_MAX_PAIRED default 2->3
- config BT_BAP_UNICAST_CLIENT_ASE_SNK_COUNT default 2->3
- config LC3_ENC_CHAN_MAX default 2->3
nrf\applications\nrf5340_audio\tools\buildprog\nrf5340_audio_dk_devices.json
source 1:"nrf5340_audio_dk_dev": "gateway","channel": "NA"
- sink 3:"nrf5340_audio_dk_dev": "headset","channel": "right" and "left" and "right"
build and running is success.
but they don't work as 3ch. Source device connects to 2 sink devices, 1 sink device as "right" is not connected.

[quote userid="103347" url="~/f/nordic-q-a/116645/nrf5340-audio-dk-i-want-to-set-to-audio-demo-to-3ch-sink/513231"]Yes use those. CONFIG_AUDIO_BIT_DEPTH_16 gives you 16bit. 16*48khz = 96kBps.[/quote]

Thank you. I will add it in nrf\applications\nrf5340_audio\prj.conf.

As I said above, I am still having issues.
The 1 source device does not connect to the 3 sink devices.
Would you help me?

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Elfving — Tue, 03 Dec 2024 13:51:59 GMT

What NCS version are you using. I see that you are linking to documentation for NCS 2.0.2, I just wanted to mention that I would definitely recommend using newer NCS versions for Audio, at least NCS >=2.6.0, due to how rapidly the LE Audio support is evolving.

[quote user="Pio_NSatou"]I only just try like this link, channel as "left" , "right" and "center". The build can't work.
[/quote][quote user="Pio_NSatou"]I have already created a 3ch sound source.
The left, right and center structure can be said to be the first, second and third channels in other words.
[/quote]

I'm not sure if I understand. How did you set up this 3 channel system?

[quote user="Pio_NSatou"]How should I do? for example, these parameter?
[/quote]

Yes use those. CONFIG_AUDIO_BIT_DEPTH_16 gives you 16bit. 16*48khz = 96kBps.

Regards,

Elfving

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Pio_NSatou — Fri, 29 Nov 2024 12:15:18 GMT

Let me give more information about my situation.
See this picture.
I have already created a 3ch sound source.
The left, right and center structure can be said to be the first, second and third channels in other words.

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Pio_NSatou — Fri, 29 Nov 2024 12:01:40 GMT

Hello Mr.Elfving
thank you for your answer.

I reply your question. and I ask more question.

[quote userid="103347" url="~/f/nordic-q-a/116645/nrf5340-audio-dk-i-want-to-set-to-audio-demo-to-3ch-sink/511901"]Its also true that one could theoretically decrease the quality from 96 kbps. [/quote]

How should I do? for example, these parameter?
https://docs.nordicsemi.com/bundle/ncs-2.0.2/page/nrf/applications/nrf5340_audio/README.html#cmdoption-arg-CONFIG_AUDIO_SAMPLE_RATE_HZ
same url CONFIG_AUDIO_SAMPLE_RATE_HZ/CONFIG_AUDIO_BIT_DEPTH_16/CONFIG_ENCODER_THREAD_PRIO

[quote userid="103347" url="~/f/nordic-q-a/116645/nrf5340-audio-dk-i-want-to-set-to-audio-demo-to-3ch-sink/511901"]Yeah there is some limitation there as well which I believe depends on the controller used. Could you tell me where you found this?[/quote]

I only just try like this link, channel as "left" , "right" and "center". The build can't work.
https://docs.nordicsemi.com/bundle/ncs-2.0.2/page/nrf/applications/nrf5340_audio/README.html#preparing_the_json_file

So would you tell me how to set source device?

[quote userid="103347" url="~/f/nordic-q-a/116645/nrf5340-audio-dk-i-want-to-set-to-audio-demo-to-3ch-sink/511901"]Try adding a center one in addition to left and right. Have one stereo CIG for the left and right channels, and let the last mono one be your sink center.[/quote]

I checked all of your URL Link. but I don't know where to find useful information for my situation.
So would you tell me how to set sink device?

RE: nRF5340 Audio DK. I want to set to Audio Demo to 3ch sink

Elfving — Mon, 25 Nov 2024 13:13:51 GMT

Hello,

[quote user=""]

1. The chip does not have the processing power to stream 3ch audio.

[/quote]

First of all, you are somewhat right in this. If you want 3 different streams set up from one source that might be a bit much for nRF5340 to handle. There is a rule of thumb which states that nF5340 wuld spend about 30% of its computational power on one of these streams with 96 kbps. So if you would even do 2 of them, you need to make sure that you are not doing anything too intensive in addition to that. 3 however would easily be a bit much if you want anything on top of this. It is also rather common to want some further audio processing in addition to sending out the streams themselves, so this is important to keep in mind.

Its also true that one could theoretically decrease the quality from 96 kbps. You could also simply back the left and right streams into one stereo CIS stream, meaning that you essentially have two streams here.

[quote user=""]

2.The source output cannot be set to output 3ch.

[/quote]

Yeah there is some limitation there as well which I believe depends on the controller used. Could you tell me where you found this?

[quote user=""]

3.The sink set cannot be set to left, right, and center.

[/quote]

Meaning all of them at the same time? I thought that should be possible.

Try adding a center one in addition to left and right. Have one stereo CIG for the left and right channels, and let the last mono one be your sink center.

For more on how to configure them for this, see here.

Regards,

Elfving