Question

I’ve searched similar topics but cannot find a clear and concise answer. I’ve been trying to figure out a way I could determine the decibel level output at a given point of time while the Android media player is being played. I cannot find a way to determine how loud the phone is at a given point in time when a song is being played. I’ve been looking over the media player API but I cannot figure out how I can get a reading at a given time during a song being played.

Any ideas or help appreciated.

Answer 1

I think you have to record audio to using MediaRecorder :

mRecorder = new MediaRecorder();
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mRecorder.setOutputFile("/dev/null"); 
mRecorder.prepare();
mRecorder.start();

---

   public double getAmplitude() {
            if (mRecorder != null)
                    return  (mRecorder.getMaxAmplitude());
            else
                    return 0;

    }

---

To calculate Db value :

  powerDb = 20 * log10(getAmplitude() / referenceAmp);

It is common to choose the maximum signal magnitude as the reference amplitude. That is, we normalize the signal so that the maximum amplitude is defined as 1, or 0 dB