"ALSA Audio Capture" and "ALSA Audio Playback" simulink blocks working with multichannel audio.

The "ALSA Audio Capture" and the "ALSA Audio Playback" blocks of the Simulink Support Package for Raspberry Pi Hardware work with N-by-2 frame of int16 values. I would like to know if it is possible to edit these blocks in order to work in a multichannel audio configuration (more than 2 audio channels), for example with the Audio Injector Octo multichannel sound for the Raspberry Pi. Thanks.

Answer 1

[Joe Murphy]

Hello Antonio,

These blocks do not currently support multichannel audio (above 2 audio channels), and editing these library blocks is not a supported workflow.

However, if you really wanted to you can edit these blocks by breaking the library links and editing the S-functions to handle more audio channels. In order to do this you can first follow the steps below:

1. Right-click the block (either 'ALSA Audio Capture' or 'ALSA Audio Playback') and navigate to Library Link > Disable Link.

2. Right-click again and navigate to Library Link > Break Link.

3. Once the link is broken, right-click the block again and navigate to Mask > Look Under Mask. Once the Block Parameters dialog window appears, click the 'Edit' button to open the S-function associated with this block.

At this point, you will need to edit the S-function's code appropriately in order to allow it to handle multichannel audio. Please note that this may be difficult or time-consuming to implement and it is again an unsupported and not recommended workflow. You can read more about S-functions in the documentation overview below:

https://www.mathworks.com/help/rtw/s-functions.html?s_tid=srchtitle