Microphone audio capture arrives in Linux on Chromebooks. Here’s how to use it

At long last one of the major features I’ve missed from Linux on Chrome OS has arrived. And nobody even told us. I’m talking about audio capture in a Linux container on Chromebooks. You can actually use it now on the Chrome OS 79 Stable Channel that launched a few weeks ago.

Normally experimental new features are hidden behind a Chrome OS flag but audio capture hasn’t even reached that stage yet. Instead, you have to start Termina, the virtual machine where your Linux containers run on a Chromebook, with a command line flag.

To enable audio capture through either your Chromebook’s built-in microphone or a USB mic, go in the Chrome browser and press the ctrl – alt – T keyboard combination. This should open up what’s known as the crosh shell.

Next type the vmc stop termina command to shut down any currently running Termina VM. Then restart termina with this command: vmc start termina –enable-audio-capture. Then, simply launch your Terminal app.

Enable audio capture in Chrome OS
Enable audio capture in Chrome OS

Once you do, Linux apps will have access to any internal or external microphones.

I tested this with Audacity, an open-source audio application I’ve used for podcasting since 2006. I did have to choose the right audio input from the many listed options, but once I found the correct one — sysdefault: Mic 0 worked for my Samson USB mic — I was able to record and save audio.

Choose microphone input on Chrome OS in Audacity

This method to enable audio capture won’t be needed for long thankfully. It was added as a way to test the feature. A Chrome OS experimental flag will arrive in a future version of Chrome OS; I wouldn’t be surprised if it found its way into Chrome OS 80 since it’s a relatively small change to add a flag.

Eventually, just like GPU hardware acceleration, audio capture in Linux on Chromebooks will be enabled by default, although I wouldn’t expect that scenario for a few Chrome OS software versions yet.

8 thoughts on “Microphone audio capture arrives in Linux on Chromebooks. Here’s how to use it

  • January 2, 2020 at 1:03 pm
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    Once again, Crostini is SO far behind Crouton. I have been running Audacity under Ubuntu via Crouton since I had my first Chromebook and discovered Crouton. How is it that an individual Google employee, apparently in his spare time, can accomplish a full implementation, when Google with all its resources limps along adding one feature after another to Crostini at a snail/s pace? And with the xiwi paramter (X in a window) there is no need for hot-key switching between Chrome and LInux – a simple click in the desired window switches between Chrome and LInux.

    Reply
    • January 2, 2020 at 5:06 pm
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      Good luck developing a fully-featured Linux VM that performs well without compromising Chrome OS security such as powerwashing to Dev Mode. xiwi doesn’t even have GPU acceleration.

      Reply
    • January 3, 2020 at 4:17 am
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      You’re not giving google enough credit here and comparing crostini to crouton is like apples to oranges. Crouton is simple because its just using linux natively and as such it has all the security pitfalls of any normal os. Crostini however is fully containerised and sandboxed meaning that they pretty much have to reimplement everything from scratch (driver etc) in order to redirect those resources to the chrome os layer in completely secure and isolated manner whilst still appearing as though it were native.
      Trust me this is v hard, it hasn’t been done before on this scale. It would be like google creating a new vmware product from scratch, something thats been developed for decades at this point.

      Reply
    • January 3, 2020 at 4:55 am
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      That’s because Google is afraid of direct hardware access and they want to put everything behind a virtualized container, even though ChromeOS is basically a stripped away Gentoo

      Reply
    • January 3, 2020 at 9:22 am
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      Yes – they should just put Windows on it. I remember I was capturing audio on Windows systems years ago.

      Reply
  • January 3, 2020 at 2:46 pm
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    Should be two dashes on second command

    crosh> vmc stop termina
    crosh> vmc start termina –enable-audio-capture

    Reply
    • January 3, 2020 at 7:47 pm
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      Thanks for the — recommendatoin

      Reply
    • January 4, 2020 at 10:26 am
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      Yup, I typed two dashes but WordPress merged them. The correct command is shown in the screenshot. Thanks!

      Reply

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