AudioSource value for USB microphone on Android

Question

An audio capture application on rooted MK809/Android 4.1.1. There is no internal mic so I am trying to use a USB one which is correctly detected as "USB Audio Device" in Settings/Sound/Sound Devices Manager/Sound Input Devices when connected.

What is this device's AudioSource value to pass into AudioRecord constructor (first argument). I tried every one in MediaRecorder.AudioSource, none worked. I am only interested in reading the capture buffer, not saving into a file.

Answer 1

Answering my own question. The following values did work: DEFAULT, MIC, CAMCORDER, probably others too as it is the only input device.

I was trying to use sample rate of 48000 (works on Windows) and AudioRecord creation failed with:

ERROR/AudioRecord(1615): Could not get audio input for record source 1 ERROR/AudioRecord-JNI(1615): Error creating AudioRecord instance: initialization check failed. ERROR/AudioRecord-Java(1615): [ android.media.AudioRecord ] Error code -20 when initializing native AudioRecord object.

Somewhat misleading info considering that a call to getMinBufferSize() with the same set of agruments does not return an error as it is supposed to. I assumed that it was a valid sample rate for the device. Setting it to 44100 (guranteed) fixed the problem.

USB audio input devices do work on Android, Jelly Bean at least. Hope this helps someone.