Android - How to get decibel with bytes audio raw data?

I want to display the microphone usage status in android. I would like to display when more than a certain decibel. What I can get is raw data in bytes [] and usage time. How can I get a decibel through this?

 @Override  public void processData(byte[] samples, double streamtimeMill) {      super.processData(samples, streamtimeMill);      calculatePeakAndRms(encodeToSample(samples,samples.length));  }    public short[] encodeToSample(byte[] srcBuffer, int numBytes) {      byte[] tempBuffer = new byte[2];      int nSamples = numBytes / 2;      short[] samples = new short[nSamples];  // 16-bit signed value        for (int i = 0; i < nSamples; i++) {          tempBuffer[0] = srcBuffer[2 * i];          tempBuffer[1] = srcBuffer[2 * i + 1];          samples[i] = bytesToShort(tempBuffer);      }        return samples;  }    public short bytesToShort(byte [] buffer) {      ByteBuffer bb = ByteBuffer.allocate(2);      bb.order(ByteOrder.BIG_ENDIAN);      bb.put(buffer[0]);      bb.put(buffer[1]);      return bb.getShort(0);  }    public void calculatePeakAndRms(short [] samples) {          double sumOfSampleSq = 0.0;    // sum of square of normalized samples.          double peakSample = 0.0;     // peak sample.            for (short sample : samples) {              double normSample = (double) sample / 32767;  // normalized the sample with maximum value.              sumOfSampleSq += (normSample * normSample);              if (Math.abs(sample) > peakSample) {                  peakSample = Math.abs(sample);              }          }            double rms = 10 * Math.log10(sumOfSampleSq / samples.length);          double peak = 20 * Math.log10(peakSample / 32767);          Log.v("rms", rms + "");          Log.v("peak", peak + "");  }  

I tried running this code, but the value printed in rms is between -4 and -9, which doesn't seem to be the actual decibel. Most of the code is described in terms of short [] so it's hard to find my case. How can I change byte[] to decibel?

https://stackoverflow.com/questions/67259962/android-how-to-get-decibel-with-bytes-audio-raw-data April 26, 2021 at 09:58AM