Which /dev/... (devices) are the microphone and speaker in Mac OS X?

axelbrz picture axelbrz · Feb 14, 2013 · Viewed 10.5k times · Source

I have a MacBook Alluminium and I want to capture the microphone in a RAW format and output a RAW audio through the speakers, in a standard way, i.e., using the terminal with standard Unix commands and using the standard /dev/??? devices.

So, the question/s:

  • Which devices are the microphone and speakers? Those both should start with /dev/...

  • Are they different if they are built-in or external? Which ones? (Also they have to start with /dev/...)

If you know also the unix commands to print the microphone input and to write the output for speakers that would be extra points! :) (I want to capture it from mic, modify it -I got it-, and send it modified to speakers)

If you know also the Assembly instructions for OSX that would be the perfection! But the main questions are which are in the bulleted list.

Thanks!

Answer

duskwuff -inactive- picture duskwuff -inactive- · Feb 14, 2013

None of them. Not all devices have /dev nodes on Mac OS X, and audio devices are not among them. There is no way I'm aware of to access audio devices using only "standard" terminal commands. sox can be used if you install it, but it is not shipped with Mac OS X.

The primary supported API to access audio devices on Mac OS X is Core Audio. Third-party libraries, such as libao, are also available which can expose a simpler, platform-independent interface to Core Audio.