nrf5340 Stereo Audio

RE: nrf5340 Stereo Audio

Adarsh_1 — Wed, 28 Sep 2022 11:41:41 GMT

Hi,

Thank you Einarh for your reply.

I will leave it open just in case I face problems while implementing the suggested methods.

Best regards,

Adarsh

RE: nrf5340 Stereo Audio

Einarh — Tue, 27 Sep 2022 11:46:37 GMT

Looking at the le_audio_send function, the stereo stream is split into two mono streams by two different calls of iso_stream_send.

Here AUDIO_CH_R and AUDIO_CH_L simply indicate what iso channel to send the data on.

So if you want to send a stereo stream, you can simply send all the data with a single call of iso_stream_send by doubling the sdu_size.

You'll then have to split the received data in two on the headset side.

Best regards,

Einar

RE: nrf5340 Stereo Audio

Adarsh_1 — Fri, 23 Sep 2022 13:15:22 GMT

Hai Einarh,

Thank you for your reply. Yours suggestions are on point.

I have decided to use NCS V2.1.0.

[quote userid="111520" url="~/f/nordic-q-a/92123/nrf5340-stereo-audio/387426"]If you compare the implementation of streamctrl_encoded_data_send in 2.1 and 2.0:[/quote]

I am struggling here somehow. I am not able to modify the le_audio_send function to make it work.

[quote userid="111520" url="~/f/nordic-q-a/92123/nrf5340-stereo-audio/387426"]It seems like ble_trans_iso_tx is the function you're looking for, and it seems to take an option for mono/stereo.[/quote]

Since now I am using NCSV2.1.0, I cannot find this function anymore. What is the equivalent function in ncsv2.1.0?

[quote userid="111520" url="~/f/nordic-q-a/92123/nrf5340-stereo-audio/387426"]You should here modify the le_audio_send function so that it sends stereo data[/quote]

Can you please shed more light on how this can be done. I assume it is not that easy as changing the parameter in ble_trans_iso_tx from mono to stereo.

iso_stream_send () does not seems to support stereo. I assume this function has to be properly modified. Is it correct? How you please explain how this could be done?

ret = iso_stream_send(data, sdu_size, AUDIO_CH_L);
	if (ret) {
		LOG_DBG("Failed to send data to left channel");
	}

Thanks for your time.

best regards,

Adarsh

RE: nrf5340 Stereo Audio

Einarh — Thu, 22 Sep 2022 08:38:22 GMT

You should here modify the le_audio_send function so that it sends stereo data

If you compare the implementation of streamctrl_encoded_data_send in 2.1 and 2.0:

https://github.com/nrfconnect/sdk-nrf/blob/v2.1-branch/applications/nrf5340_audio/src/audio/streamctrl.c#L211

https://github.com/nrfconnect/sdk-nrf/blob/v2.0-branch/applications/nrf5340_audio/src/audio/streamctrl.c#L226

It seems like ble_trans_iso_tx is the function you're looking for, and it seems to take an option for mono/stereo.

make the headset device expect to receive a stereo stream

These seem to be the corresponding functions in 2.1 and 2.0:

https://github.com/nrfconnect/sdk-nrf/blob/v2.1-branch/applications/nrf5340_audio/src/audio/audio_system.c#L68

https://github.com/nrfconnect/sdk-nrf/blob/v2.0-branch/applications/nrf5340_audio/src/audio/audio_codec.c#L308

Hope this helps

-Einar

RE: nrf5340 Stereo Audio

Einarh — Tue, 20 Sep 2022 12:59:16 GMT

I'm looking into your issue, but I might need some time to get up to speed on your case.

Best regards,

Einar