How to get the amplitude when blowing into MIC on android device

Question

How to get the amplitude when blowing into MIC in android device.

MediaRecorder recorder = new MediaRecorder();
   recorder.setAudioSource(MediaRecorder.AudioSource.MIC);

   Timer timer = new Timer();
   timer.scheduleAtFixedRate(new RecorderTask(recorder), 0, 1000);

private class RecorderTask extends TimerTask {
private MediaRecorder recorder;

public RecorderTask(MediaRecorder recorder) {
    this.recorder = recorder;
}

public void run() {
    Log.v("", "amplitude is" + recorder.getMaxAmplitude());
}
}

I am getting an error:

ERROR/AndroidRuntime(20927): Caused by: java.lang.RuntimeException: setAudioSource failed.
ERROR/AndroidRuntime(20927): at android.media.MediaRecorder.setAudioSource(Native Method)

score 9 · Answer 1 · edited Apr 06 '12 at 05:16

public boolean isBlowing()
    {
        boolean recorder=true;

        int minSize = AudioRecord.getMinBufferSize(8000,AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
        AudioRecord ar = new AudioRecord(MediaRecorder.AudioSource.MIC, 8000,AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT,minSize);


        short[] buffer = new short[minSize];

        ar.startRecording();
        while(recorder)
        {

            ar.read(buffer, 0, minSize);
            for (short s : buffer) 
            {
                if (Math.abs(s) > 27000)   //DETECT VOLUME (IF I BLOW IN THE MIC)
                {
                    blow_value=Math.abs(s);
                    System.out.println("Blow Value="+blow_value);
                    ar.stop();
                    recorder=false;

                    return true;

                }

            }
        }
        return false;

    }

Its detecting all the sounds have value greater than 27000. How can we detect that its sound of blow. — Muhammad Zahab, Feb 19 '20 at 06:51

score 2 · Answer 2 · answered Jan 15 '13 at 09:28

2

You need to set up permissions on your manifest file

 <uses-permission android:name="android.permission.RECORD_AUDIO" />

answered Jan 15 '13 at 09:28

Paranoid Android

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score 0 · Answer 3 · answered May 24 '11 at 18:50

0

You have to initialize the recorder, as well as set several methods. Look at the documentation for MediaRecorder to see how to do this. I've used this method and it works quite well.

answered May 24 '11 at 18:50

Nicholas

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How to get the amplitude when blowing into MIC on android device

3 Answers3

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