Add SoundVolumeMonitor

MembraneRTC/src/main/java/org/membraneframework/rtc/media/OnSoundVolumeChangedListener.java

@@ -0,0 +1,8 @@
+package org.membraneframework.rtc.media;
+
+import org.membraneframework.rtc.models.VadStatus;
+
+@FunctionalInterface
+public interface OnSoundVolumeChangedListener {
+    void onSoundVolumeChangedListener(VadStatus value);
+}

MembraneRTC/src/main/java/org/membraneframework/rtc/media/SoundVolumeMonitor.java

@@ -0,0 +1,122 @@
+package org.membraneframework.rtc.media;
+
+
+import android.media.AudioFormat;
+import android.media.AudioRecord;
+import android.media.MediaRecorder;
+
+import org.membraneframework.rtc.models.VadStatus;
+
+import java.util.Timer;
+import java.util.TimerTask;
+
+import timber.log.Timber;
+
+public class SoundVolumeMonitor {
+    private Timer timer;
+    private AudioRecord audioRecord;
+    private OnSoundVolumeChangedListener onSoundVolumeChangedListener;
+    public boolean isRecording = false;
+    private int bufferSize;
+    private final int volumeThreshold = -100;
+    private final int monitorInterval = 1;
+    private final int samplingRate = 22050;
+
+    public void start() throws SecurityException {
+        start(monitorInterval, samplingRate);
+    }
+
+    public void start(int monitorInterval, int samplingRate) throws SecurityException {
+        if (isRecording) return;
+
+        bufferSize = AudioRecord.getMinBufferSize(samplingRate, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
+        audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, samplingRate, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);
+
+        if (audioRecord.getState() == AudioRecord.STATE_INITIALIZED) {
+            audioRecord.startRecording();
+            isRecording = true;
+            startTimer(monitorInterval);
+        } else {
+            Timber.e("COULDNT_PREPARE_RECORDING AudioRecord couldn't be initialized.");
+        }
+    }
+
+    public void stop() {
+        if (!isRecording) {
+            Timber.e("INVALID_STATE Please call start before stopping recording");
+            return;
+        }
+        stopTimer();
+        isRecording = false;
+        try {
+            audioRecord.stop();
+            audioRecord.release();
+        } catch (final RuntimeException e) {
+            Timber.e("RUNTIME_EXCEPTION No valid audio data received. You may be using a device that can't record audio.");
+        } finally {
+            audioRecord = null;
+        }
+    }
+
+    public void setSoundVolumeListener() {
+    }
+
+    public void setSoundVolumeListener(OnSoundVolumeChangedListener listener) {
+        onSoundVolumeChangedListener = listener;
+    }
+    public void setIsSoundDetected(VadStatus newValue) {
+        onSoundVolumeChangedListener.onSoundVolumeChangedListener(newValue);
+    }
+    private void detectSound(int volumeValue){
+        detectSound(volumeThreshold,volumeValue);
+    }
+    private void detectSound(int volumeThreshold, int volumeValue) {
+        if (volumeValue > volumeThreshold) {
+            setIsSoundDetected(VadStatus.SPEECH);
+        } else {
+            setIsSoundDetected(VadStatus.SILENCE);
+        }
+    }
+
+    private int getMaxAmplitude(short[] buffer, int bytesRead) {
+        int maxAmplitude = 0;
+        for (int sample : buffer) {
+            maxAmplitude = Math.max(maxAmplitude, Math.abs(sample));
+        }
+        return maxAmplitude;
+    }
+
+    private int calculateValue(int maxAmplitude) {
+        if (maxAmplitude <= 0) {
+            return -160;
+        }
+        return (int) (20 * Math.log(((double) maxAmplitude) / 32767d));
+    }
+
+    private int readAudioData(short[] buffer) {
+        return audioRecord.read(buffer, 0, bufferSize);
+    }
+
+    private void startTimer(int monitorInterval) {
+        timer = new Timer();
+        timer.scheduleAtFixedRate(new TimerTask() {
+            @Override
+            public void run() {
+                short[] buffer = new short[bufferSize];
+                int bytesRead = readAudioData(buffer);
+                int amplitude = getMaxAmplitude(buffer, bytesRead);
+                int value = calculateValue(amplitude);
+                detectSound(value);
+            }
+        }, 0, monitorInterval);
+    }
+
+    private void stopTimer() {
+        if (timer != null) {
+            timer.cancel();
+            timer.purge();
+            timer = null;
+        }
+    }
+}
+