How to sample microphone on Android without recording to get live amplitude/level?

Question

I was trying to get the amplitude level of a microphone on Android like so:

MediaRecorder recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecord         


        

Answer 1

The solution from Toumal works, however I wasn't able to get a high enough refresh rate for my needs. So I ended up using the SoundMeter.java class that Toumal linked but modified it to use the code from this answer

Here is the code I used, which provides a much better refresh rate:

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;

public class SoundMeter {

    private AudioRecord ar = null;
    private int minSize;

    public void start() {
        minSize= AudioRecord.getMinBufferSize(8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
        ar = new AudioRecord(MediaRecorder.AudioSource.MIC, 8000,AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT,minSize);
        ar.startRecording();
    }

    public void stop() {
        if (ar != null) {
            ar.stop();
        }
    }

    public double getAmplitude() {
        short[] buffer = new short[minSize];
        ar.read(buffer, 0, minSize);
        int max = 0;
        for (short s : buffer)
        {
            if (Math.abs(s) > max)
            {
                max = Math.abs(s);
            }
        }
        return max;
    }

}