Balena Audio Block Custom PA Script

[lukasknk]

Hello

In order to properly use the Balena Audio block and actually output sound via my chosen Output i need to be able to set the following in a custom.pa script.

set-card-profile 0 output:hdmi-stereo

I found this to work by cloning the audio block and adding this as suggested in the documentation to the start cmd:

COPY custom.pa /usr/src/custom.pa
CMD [ "pulseaudio", "--file /usr/src/custom.pa" ]

My problem is now that i don’t know how to add a custom.pa file to a balena block. Currently i have cloned the audio balena block manually and added this inside that block code. This works perfectly fine but isn’t really the solution i’m looking for because it means that i need to have a local copy of the block and can therefore not profit from the advantages of a balena block.

Can someone help me with adding a custom pulse audio script to the balena audio block?

Thanks.

[ramirogm]

Hi lukasknk

It sounds like you’ve managed to adapt the balena block to your needs by using a custom script, and now you’d like to reuse this block. What you can do is publish your custom version ( fork ) of the balena audio block as your own block. You can keep this new block private or make it public.

The overall steps are described in Develop with blocks - Balena Documentation

I’ve done them based on what you describe on my own, so you can use this as a reference.

First I forked the balena audio GitHub repo into my own org: GitHub - ramirogm/audio: Audio building block for balenaOS, based on pulseaudio.

I then added your custom.pa script and edited the Dockerfile file, committed and pushed the changes.

The next step is to publish the changes. I went to my balena cloud dashboard and selected blocks on the left, created a new block, selected it, went to the “releases” page, and added a new one. This will show you that you need to run the following commands:

balena login
 balena push ramiro_gonzalez/audio

( obvs using your own organization )

If all goes well, you should see a happy unicorn at the end of the building process, and a new “release” on the block’s releases page on the dashboard.

You can then use this block on your docker-compose file using the “image reference” shown on the block Summary page. In my case, it’s bh.cr/ramiro_gonzalez/audio

Last step: I made the block public as explained in Develop with blocks - Balena Documentation

Let me know if this helps!

Ramiro

[ramirogm]

Here are some screenshots of the steps described above:

Create a block:

Block properties:

Adding a release

The release is building after executing balena push

[lukasknk]

Thanks for that.

It wasn’t clear to me that the only way to adjust these things was to create a custom block. But that is good to know. Thanks for your help, this seemed to have been the solution i’m looking for.

[ramirogm]

Hi
Glad it helped! Let me know how it goes
Ramiro

[lukasknk]

Worked perfectly, thanks for your support.