puhh. this is a big commit

- change the complete file sending / receiving process between phone and watch, we now use channels instead of simple messages. this is recommentad by google, due to some changes in google play services.
- made some smaller changes in the ui, for file saving and saving of sensordata for evaluation purposes
- edited the manifest and gradle script for play store.
- made some change for a better performance for he huawei watch

android/ConductorsPhone/app/build.gradle

@@ -11,8 +11,8 @@ android {
         minSdkVersion 24
         targetSdkVersion 26
         //sdk 2 | product version 3 | build num 2 | multi-apk 2
-        versionCode 260120100
-        versionName "0.1.2"
+        versionCode 260130300
+        versionName "0.1.3.2"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     buildTypes {
@@ -33,12 +33,12 @@ dependencies {
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.1'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
-    implementation 'com.google.android.support:wearable:2.1.0'
+    implementation 'com.google.android.support:wearable:2.2.0'
     implementation 'com.google.android.gms:play-services-wearable:11.8.0'
     implementation 'com.android.support:percent:26.1.0'
     implementation 'com.android.support:animated-vector-drawable:26.1.0'
     implementation 'com.android.support:appcompat-v7:26.1.0'
     implementation 'com.android.support:support-v4:26.1.0'
     implementation 'com.android.support:recyclerview-v7:26.1.0'
-    compileOnly 'com.google.android.wearable:wearable:2.1.0'
+    compileOnly 'com.google.android.wearable:wearable:2.2.0'
 }

android/ConductorsPhone/app/src/main/AndroidManifest.xml

@@ -3,13 +3,12 @@
     package="de.tonifetzer.conductorswatch">
 
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
-    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
 
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
-        android:roundIcon="@mipmap/ic_launcher_round"
+        android:roundIcon="@mipmap/ic_launcher"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
 

android/ConductorsWatch/app/build.gradle

@@ -9,8 +9,8 @@ android {
         minSdkVersion 23
         targetSdkVersion 26
         //sdk 2 | product version 3 | build num 2 | multi-apk 2
-        versionCode 260120101
-        versionName "0.1.2"
+        versionCode 260130301
+        versionName "0.1.3.2"
     }
     buildTypes {
         release {
@@ -22,6 +22,7 @@ android {
         wear1 {
             dimension "minSdk"
             // Use the defaultConfig value
+            minSdkVersion 23
         }
         wear2 {
             dimension "minSdk"
@@ -36,8 +37,8 @@ android {
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation 'com.google.android.support:wearable:2.1.0'
+    implementation fileTree(include: ['*.jar'], dir: 'libs')
+    implementation 'com.google.android.support:wearable:2.2.0'
     implementation 'com.google.android.gms:play-services-wearable:11.8.0'
     implementation 'com.android.support:percent:26.1.0'
     implementation 'com.android.support:animated-vector-drawable:26.1.0'
@@ -45,6 +46,6 @@ dependencies {
     implementation 'com.android.support:support-v4:26.1.0'
     implementation 'com.android.support:recyclerview-v7:26.1.0'
     implementation 'com.android.support:wear:26.1.0'
-    compileOnly 'com.google.android.wearable:wearable:2.1.0'
+    compileOnly 'com.google.android.wearable:wearable:2.2.0'
     compile 'com.github.wendykierp:JTransforms:3.1'
 }

android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/Estimator.java

@@ -30,7 +30,7 @@ public class Estimator implements SensorEventListener {
 
     private SensorManager mSensorManager;
     private Sensor mAccelerometer;
-    private Sensor mGyroscope;
+    private Sensor mRawAccelerometer;
     private Context mContext;
     private AccelerometerWindowBuffer mAccelerometerWindowBuffer;
     private BpmEstimator mBpmEstimator;
@@ -50,11 +50,11 @@ public class Estimator implements SensorEventListener {
 
         mSensorManager = (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE);
         mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
-        mGyroscope = mSensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
+        mRawAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
         mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_FASTEST);
-        mSensorManager.registerListener(this, mGyroscope, SensorManager.SENSOR_DELAY_FASTEST);
+        mSensorManager.registerListener(this, mRawAccelerometer, SensorManager.SENSOR_DELAY_FASTEST);
 
-        mAccelerometerWindowBuffer = new AccelerometerWindowBuffer(1024, 256);
+        mAccelerometerWindowBuffer = new AccelerometerWindowBuffer(6000, 1500);
         mBpmEstimator = new BpmEstimator(mAccelerometerWindowBuffer, 0, 5000);
 
         mTimer.scheduleAtFixedRate(new TimerTask() {
@@ -110,9 +110,8 @@ public class Estimator implements SensorEventListener {
                 mByteStreamWriterAcc.reset();
             }
 
-            if (se.sensor.getType() == Sensor.TYPE_GYROSCOPE) {
-                //TODO: Rename AccelerometerData to SensorData3D
-                mByteStreamWriterGyro.writeSensor3D(Sensor.TYPE_GYROSCOPE,  se.values[0], se.values[1], se.values[2]);
+            if (se.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
+                mByteStreamWriterGyro.writeSensor3D(Sensor.TYPE_ACCELEROMETER,  se.values[0], se.values[1], se.values[2]);
 
                 mStreamer.sendByteArray(mByteStreamWriterGyro.getByteArray());
                 mByteStreamWriterGyro.reset();

android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/AccelerometerWindowBuffer.java

@@ -12,35 +12,49 @@ public class AccelerometerWindowBuffer extends ArrayList<AccelerometerData> {
     private int mOverlapSize;
     private int mOverlapCounter;
 
-    public AccelerometerWindowBuffer(int windowSize, int overlap){
-        mWindowSize = windowSize;
-        mOverlapSize = overlap;
-        mOverlapCounter = 1;
+    public AccelerometerWindowBuffer(int windowSize_ms, int overlap_ms){
+        mWindowSize = windowSize_ms;
+        mOverlapSize = overlap_ms;
+        mOverlapCounter = 0;
     }
 
     //TODO: add exception handling. falseArgument if ad has no numeric x,y,z
     public boolean add(AccelerometerData ad){
         synchronized (this){
+
             //do not add duplicates!
-            if (!isEmpty() && getYongest().equals(ad)) {
+            if(!isEmpty() && getYongest().equals(ad)){
                 return false;
             }
 
-            boolean r = super.add(ad);
-            if (size() > mWindowSize) {
-                removeRange(0, size() - mWindowSize);
+            // current - last to increment overlap time
+            if(!isEmpty()){
+                mOverlapCounter += ad.ts - getYongest().ts;
             }
 
-            ++mOverlapCounter;
+            //add element
+            boolean r = super.add(ad);
+            if ((getYongest().ts - getOldest().ts) > mWindowSize){
+
+                long oldestTime = getYongest().ts - mWindowSize;
+                for(int i = 0; i < size(); ++i) {
+                    if (get(i).ts > oldestTime) {
+                        break;
+                    }
+                    remove(i);
+                }
+            }
             return r;
         }
     }
 
     public boolean isNextWindowReady(){
-        if((size() > mWindowSize / 2) && mOverlapCounter > mOverlapSize){
-            mOverlapCounter = 1;
+        if(!isEmpty()){
+            if(((getYongest().ts - getOldest().ts) > mWindowSize / 2) && mOverlapCounter > mOverlapSize){
+                mOverlapCounter = 0;
 
-            return true;
+                return true;
+            }
         }
         return false;
     }

android/ConductorsWatch/app/src/main/java/de/tonifetzer/conductorswatch/bpmEstimation/BpmEstimator.java

@@ -58,13 +58,16 @@ public class BpmEstimator {
         //just look at the newest 512 samples
         //List<AccelerometerData> subBuffer =  mBuffer.subList(mBuffer.size() - 512, mBuffer.size());
 
-        double[] xAutoCorr = new AutoCorrelation(interp.getX(), 512).getCorr();
-        double[] yAutoCorr = new AutoCorrelation(interp.getY(), 512).getCorr();
-        double[] zAutoCorr = new AutoCorrelation(interp.getZ(), 512).getCorr();
+        double[] xAutoCorr = new AutoCorrelation(interp.getX(), fixedWindow.size()).getCorr();
+        double[] yAutoCorr = new AutoCorrelation(interp.getY(), fixedWindow.size()).getCorr();
+        double[] zAutoCorr = new AutoCorrelation(interp.getZ(), fixedWindow.size()).getCorr();
 
-        Peaks pX = new Peaks(xAutoCorr, 50, 0.1f, 0, false);
-        Peaks pY = new Peaks(yAutoCorr, 50, 0.1f, 0, false);
-        Peaks pZ = new Peaks(zAutoCorr, 50, 0.1f, 0, false);
+
+        //find a peak within range of 250 ms
+        int peakWidth = (int) Math.round(250 / sampleRate);
+        Peaks pX = new Peaks(xAutoCorr, peakWidth, 0.1f, 0, false);
+        Peaks pY = new Peaks(yAutoCorr, peakWidth, 0.1f, 0, false);
+        Peaks pZ = new Peaks(zAutoCorr, peakWidth, 0.1f, 0, false);
 
         mBpmHistory_X.add(pX.getBPM(sampleRate));
         mBpmHistory_Y.add(pY.getBPM(sampleRate));
@@ -88,7 +91,7 @@ public class BpmEstimator {
             //mResetCounter = 0;
         }
         else {
-            int resetAfter = (int) Math.round(mResetLimit_ms / (mBuffer.getOverlapSize() * sampleRate));
+            int resetAfter = (int) Math.round(mResetLimit_ms / (mBuffer.getOverlapSize()));
             if(++mResetCounter > resetAfter){
                 mBpmHistory.clear();
 

android/ConductorsWatch/build.gradle

@@ -3,8 +3,11 @@
 buildscript {
     
     repositories {
-        google()
+        maven {
+            url "https://maven.google.com"
+        }
         jcenter()
+        google()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.0.1'
@@ -17,8 +20,11 @@ buildscript {
 
 allprojects {
     repositories {
-        google()
+        maven {
+            url "https://maven.google.com"
+        }
         jcenter()
+        google()
     }
 }
 

android/ConductorsWatch/gradle.properties

@@ -10,6 +10,7 @@
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
 org.gradle.jvmargs=-Xmx1536m
+android.enableD8=true
 
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit

java/src/main/java/Main.java

@@ -16,7 +16,8 @@ import java.util.stream.IntStream;
 public class Main {
 
     public static void main(String [ ] args) {
-        File folder = new File("/home/toni/Documents/programme/dirigent/measurements/wearR");
+        //File folder = new File("/home/toni/Documents/programme/dirigent/measurements/lgWear");
+        File folder = new File("/home/toni/Documents/programme/dirigent/measurements/peter_failed");
         File[] listOfFiles = folder.listFiles();
 
         Utils.ShowPNG windowRaw = new Utils.ShowPNG();
@@ -30,7 +31,8 @@ public class Main {
         for (File file : listOfFiles) {
             if (file.isFile() && file.getName().contains(".csv")) {
 
-                AccelerometerWindowBuffer accWindowBuffer = new AccelerometerWindowBuffer(1024, 256);
+                //TODO: mach Fenster genau 6 sekunden groß. Egal wie viele Samples.
+                AccelerometerWindowBuffer accWindowBuffer = new AccelerometerWindowBuffer(6000, 1500);
                 BpmEstimator bpmEstimator = new BpmEstimator(accWindowBuffer, 0, 5000);
 
                 //read the file line by line
@@ -40,7 +42,7 @@ public class Main {
                         String[] measurement = line.split(";");
 
                         //if linear acc
-                        if(measurement[1].equals("2")){
+                        if(measurement[1].equals("10")){
                             long ts = Long.parseLong(measurement[0]);
                             double x = Double.parseDouble(measurement[2]);
                             double y = Double.parseDouble(measurement[3]);
@@ -54,8 +56,9 @@ public class Main {
                             double curBpm = bpmEstimator.estimate();
                             //System.out.println("BPM: " + curBpm);
 
-
-                            AccelerometerInterpolator acInterp = new AccelerometerInterpolator(accWindowBuffer, 5);
+                            double sampleRate = 20;
+                            AccelerometerInterpolator acInterp = new AccelerometerInterpolator(accWindowBuffer, sampleRate);
+                            int peakWidth = (int) Math.round(250 / sampleRate);
 
                             //print raw x,y,z
                             double[] dTs = IntStream.range(0, accWindowBuffer.getTs().length).mapToDouble(i -> accWindowBuffer.getTs()[i]).toArray();
@@ -70,9 +73,9 @@ public class Main {
                             windowRaw.set(plotRaw.draw());
 
                             //auto corr
-                            double[] xAutoCorr = new AutoCorrelation(acInterp.getX(), 512).getCorr();
-                            double[] yAutoCorr = new AutoCorrelation(acInterp.getY(), 512).getCorr();
-                            double[] zAutoCorr = new AutoCorrelation(acInterp.getZ(), 512).getCorr();
+                            double[] xAutoCorr = new AutoCorrelation(acInterp.getX(), accWindowBuffer.size()).getCorr();
+                            double[] yAutoCorr = new AutoCorrelation(acInterp.getY(), accWindowBuffer.size()).getCorr();
+                            double[] zAutoCorr = new AutoCorrelation(acInterp.getZ(), accWindowBuffer.size()).getCorr();
 
                             //print autocorr
                             int[] tmp = IntStream.rangeClosed(-((xAutoCorr.length - 1)/2), ((xAutoCorr.length - 1)/2)).toArray();
@@ -86,10 +89,11 @@ public class Main {
 
                             windowAuto.set(plotCorr.draw());
 
-                            Peaks pX = new Peaks(xAutoCorr, 50, 0.1f, 0, false);
+                            Peaks pX = new Peaks(xAutoCorr, peakWidth, 0.1f, 0, false);
+                            int xOffset = xAutoCorr.length / 2;
                             LinkedList<Integer> peaksX = pX.getPeaksIdx();
 
-                            double[] dPeaksXX = IntStream.range(0, peaksX.size()).mapToDouble(i -> (peaksX.get(i) - 512)).toArray();//peaks.stream().mapToDouble(i->i).toArray();
+                            double[] dPeaksXX = IntStream.range(0, peaksX.size()).mapToDouble(i -> (peaksX.get(i) - xOffset)).toArray();//peaks.stream().mapToDouble(i->i).toArray();
                             double[] dPeaksXY = IntStream.range(0, peaksX.size()).mapToDouble(i -> (xAutoCorr[peaksX.get(i)])).toArray();
                             Plot plotPeaksX = Plot.plot(Plot.plotOpts().
                                     title("Peak Detection on X").
@@ -100,10 +104,11 @@ public class Main {
 
                             windowPeaksX.set(plotPeaksX.draw());
 
-                            Peaks pY = new Peaks(yAutoCorr, 50, 0.1f, 0, false);
+                            Peaks pY = new Peaks(yAutoCorr, peakWidth, 0.1f, 0, false);
+                            int yOffset = yAutoCorr.length / 2;
                             LinkedList<Integer> peaksY = pY.getPeaksIdx();
 
-                            double[] dPeaksYX = IntStream.range(0, peaksY.size()).mapToDouble(i -> (peaksY.get(i) - 512)).toArray();//peaks.stream().mapToDouble(i->i).toArray();
+                            double[] dPeaksYX = IntStream.range(0, peaksY.size()).mapToDouble(i -> (peaksY.get(i) - yOffset)).toArray();//peaks.stream().mapToDouble(i->i).toArray();
                             double[] dPeaksYY = IntStream.range(0, peaksY.size()).mapToDouble(i -> (yAutoCorr[peaksY.get(i)])).toArray();
                             Plot plotPeaksY = Plot.plot(Plot.plotOpts().
                                     title("Peak Detection on Y").
@@ -114,10 +119,11 @@ public class Main {
 
                             windowPeaksY.set(plotPeaksY.draw());
 
-                            Peaks pZ = new Peaks(zAutoCorr, 50, 0.1f, 0, false);
+                            Peaks pZ = new Peaks(zAutoCorr, peakWidth, 0.1f, 0, false);
+                            int zOffset = zAutoCorr.length / 2;
                             LinkedList<Integer> peaksZ = pZ.getPeaksIdx();
 
-                            double[] dPeaksZX = IntStream.range(0, peaksZ.size()).mapToDouble(i -> (peaksZ.get(i) - 512)).toArray();//peaks.stream().mapToDouble(i->i).toArray();
+                            double[] dPeaksZX = IntStream.range(0, peaksZ.size()).mapToDouble(i -> (peaksZ.get(i) - zOffset)).toArray();//peaks.stream().mapToDouble(i->i).toArray();
                             double[] dPeaksZY = IntStream.range(0, peaksZ.size()).mapToDouble(i -> (zAutoCorr[peaksZ.get(i)])).toArray();
                             Plot plotPeaksZ = Plot.plot(Plot.plotOpts().
                                     title("Peak Detection on Z").
@@ -142,10 +148,10 @@ public class Main {
                     }
                     // line is not visible here.
 
-                    double meanBPM = bpmEstimator.getMeanBpm();
-                    double medianBPM = bpmEstimator.getMedianBPM();
+                    //double meanBPM = bpmEstimator.getMeanBpm();
+                    //double medianBPM = bpmEstimator.getMedianBPM();
                     //System.out.println("MEAN BPM: " + Math.round(meanBPM));
-                    System.out.println("MEDIAN BPM: " + Math.round(medianBPM));
+                    //System.out.println("MEDIAN BPM: " + Math.round(medianBPM));
 
                 } catch (IOException e) {
                     e.printStackTrace();

java/src/main/java/bpmEstimation/AccelerometerWindowBuffer.java

@@ -8,14 +8,14 @@ import java.util.ArrayList;
  */
 public class AccelerometerWindowBuffer extends ArrayList<AccelerometerData> {
 
-    private static int mWindowSize;
-    private static int mOverlapSize;
-    private int mOverlapCounter;
+    private static int mWindowSize; // in ms
+    private static int mOverlapSize; // in ms
+    private long mOverlapCounter;
 
     public AccelerometerWindowBuffer(int windowSize, int overlap){
         mWindowSize = windowSize;
         mOverlapSize = overlap;
-        mOverlapCounter = 1;
+        mOverlapCounter = 0;
     }
 
     //TODO: add exception handling. falseArgument if ad has no numeric x,y,z
@@ -26,20 +26,33 @@ public class AccelerometerWindowBuffer extends ArrayList<AccelerometerData> {
             return false;
         }
 
-        boolean r = super.add(ad);
-        if (size() > mWindowSize){
-            removeRange(0, size() - mWindowSize);
+        // current - last to increment overlap time
+        if(!isEmpty()){
+            mOverlapCounter += ad.ts - getYongest().ts;
         }
 
-        ++mOverlapCounter;
+        //add element
+        boolean r = super.add(ad);
+        if ((getYongest().ts - getOldest().ts) > mWindowSize){
+
+            long oldestTime = getYongest().ts - mWindowSize;
+            for(int i = 0; i < size(); ++i) {
+                if (get(i).ts > oldestTime) {
+                    break;
+                }
+                remove(i);
+            }
+        }
         return r;
     }
 
     public boolean isNextWindowReady(){
-        if((size() > mWindowSize / 2) && mOverlapCounter > mOverlapSize){
-            mOverlapCounter = 1;
+        if(!isEmpty()){
+            if(((getYongest().ts - getOldest().ts) > mWindowSize / 2) && mOverlapCounter > mOverlapSize){
+                mOverlapCounter = 0;
 
-            return true;
+                return true;
+            }
         }
         return false;
     }

java/src/main/java/bpmEstimation/BpmEstimator.java

@@ -51,13 +51,15 @@ public class BpmEstimator {
 
         AccelerometerInterpolator interp = new AccelerometerInterpolator(mBuffer, sampleRate);
 
-        double[] xAutoCorr = new AutoCorrelation(interp.getX(), 1024).getCorr();
-        double[] yAutoCorr = new AutoCorrelation(interp.getY(), 1024).getCorr();
-        double[] zAutoCorr = new AutoCorrelation(interp.getZ(), 1024).getCorr();
+        double[] xAutoCorr = new AutoCorrelation(interp.getX(), mBuffer.size()).getCorr();
+        double[] yAutoCorr = new AutoCorrelation(interp.getY(), mBuffer.size()).getCorr();
+        double[] zAutoCorr = new AutoCorrelation(interp.getZ(), mBuffer.size()).getCorr();
 
-        Peaks pX = new Peaks(xAutoCorr, 50, 0.1f, 0, false);
-        Peaks pY = new Peaks(yAutoCorr, 50, 0.1f, 0, false);
-        Peaks pZ = new Peaks(zAutoCorr, 50, 0.1f, 0, false);
+        //find a peak within range of 250 ms
+        int peakWidth = (int) Math.round(250 / sampleRate);
+        Peaks pX = new Peaks(xAutoCorr, peakWidth, 0.1f, 0, false);
+        Peaks pY = new Peaks(yAutoCorr, peakWidth, 0.1f, 0, false);
+        Peaks pZ = new Peaks(zAutoCorr, peakWidth, 0.1f, 0, false);
 
         mBpmHistory_X.add(pX.getBPM(sampleRate));
         mBpmHistory_Y.add(pY.getBPM(sampleRate));
@@ -80,9 +82,12 @@ public class BpmEstimator {
             mResetCounter = 0;
         }
         else {
-            int resetAfter = (int) Math.round(mResetLimit_ms / (mBuffer.getOverlapSize() * sampleRate));
+            int resetAfter = (int) Math.round(mResetLimit_ms / (mBuffer.getOverlapSize()));
             if(++mResetCounter > resetAfter){
                 mBpmHistory.clear();
+
+                mBuffer.clear();
+                mMvg.clear();
                 mResetCounter = 0;
             }
             return -1;

java/src/main/java/utilities/MovingFilter.java

@@ -30,4 +30,9 @@ public class MovingFilter {
     public double getMedian() {
         return Utils.median(mSamples);
     }
+
+    public void clear(){
+        mSamples.clear();
+        mTotal = 0d;
+    }
 }

matlab/AutoCorrMethodNew_Watch.m

@@ -42,7 +42,8 @@
 
 
 %files = dir(fullfile('../../measurements/lgWear/', '*.csv'));
-files = dir(fullfile('../../measurements/wearR/', '*.csv'));
+%files = dir(fullfile('../../measurements/wearR/', '*.csv'));
+files = dir(fullfile('../../measurements/peter_failed/', '*.csv'));
 
 for file = files'
     
@@ -51,7 +52,7 @@ for file = files'
 
     %draw the raw acc data
     m_idx = [];
-    m_idx = (measurements(:,2)==2);
+    m_idx = (measurements(:,2)==10);
     m = measurements(m_idx, :);
 
     %Interpolate to generate a constant sample rate to 250hz (4ms per sample)
@@ -76,13 +77,15 @@ for file = files'
     figure(3);
     plot(m(:,1),m(:,5)) %z
     legend("z", "location", "eastoutside");
+    
+    waitforbuttonpress();
 
     %save timestamps
     timestamps = m(:,1);
     data = m(:,3); %only z
 
     %TODO: Different window sizes for periods under 16.3 s
-    window_size = 4096; %about 2 seconds using 2000hz, 16.3 s using 250hz
+    window_size = 2048; %about 2 seconds using 2000hz, 16.3 s using 250hz
     overlap = 256;
     bpm_per_window_ms = [];
     bpm_per_window = [];