WIP: audio recorder

app/build.gradle

@@ -37,21 +37,12 @@ dependencies {
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
 
-
-    // OpenCV (from: https://github.com/QuickBirdEng/opencv-android)
-    def opencv_version = "4.5.3.0"
-    implementation "com.quickbirdstudios:opencv:${opencv_version}"
-
-
     // Required for CameraX
-    def camerax_version = "1.2.2"
+    def camerax_version = "1.2.3"
     implementation "androidx.camera:camera-core:${camerax_version}"
     implementation "androidx.camera:camera-camera2:${camerax_version}"
     implementation "androidx.camera:camera-lifecycle:${camerax_version}"
     implementation "androidx.camera:camera-video:${camerax_version}"
     implementation "androidx.camera:camera-view:${camerax_version}"
     implementation "androidx.camera:camera-extensions:${camerax_version}"
-
-
-    implementation 'com.jjoe64:graphview:4.2.2'
 }

app/src/main/AndroidManifest.xml

@@ -3,13 +3,9 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <uses-feature android:name="android.hardware.camera"/>
-    <uses-permission android:name="android.permission.CAMERA"/>
-    <uses-permission android:name="android.permission.RECORD_AUDIO" />
 
-    <!--<uses-permission android:name="android.permission.BLUETOOTH"/>-->
-    <!--<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>-->
-    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
-    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
 
     <application
         android:allowBackup="true"

app/src/main/java/com/example/ueberwachungssystem/AudioRecorder.java

@@ -1,83 +1,76 @@
 package com.example.ueberwachungssystem;
 
 import android.content.Context;
+import android.hardware.Camera;
+import android.media.CamcorderProfile;
 import android.media.MediaPlayer;
 import android.media.MediaRecorder;
+import android.util.Log;
+import android.view.SurfaceView;
+import android.widget.VideoView;
 
 import java.io.File;
 import java.io.IOException;
-import java.time.LocalDateTime;
-import java.time.format.DateTimeFormatter;
 
 public class AudioRecorder {
     private final Context context;
+    private Camera camera;
     private MediaRecorder mediaRecorder = null;
-    private boolean isRecording = false;
-    private File outputDir;      // Default: in app files directory
-
+    private SurfaceView surfaceView;
 
     public AudioRecorder (Context context) {
         this.context = context;
-        this.outputDir = context.getFilesDir();
+        this.surfaceView = new SurfaceView(context);
     }
 
-    public void startRecording() {
-        // Handle logic
-        if (outputDir == null)
-            return;
-        if (isRecording)
-            return;
-        isRecording = true;
 
-        // Setup Audio Recorder for output Format: 3GP
+    public void startRecording() {
+
         mediaRecorder = new MediaRecorder();
+
         mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
-        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
-        mediaRecorder.setOutputFile(outputDir + "/" + generateFileName() + ".3gp");
-        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
+        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
+        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
+        mediaRecorder.setOutputFile(context.getFilesDir() + "/audio.mp3");
+
+
         try {
             mediaRecorder.prepare();
+            mediaRecorder.start();
         } catch (IOException e) {
-            e.printStackTrace();
+            Log.e("audioRecorder", "prepare() failed");
         }
-        mediaRecorder.start();
     }
 
     public void stopRecording() {
         if (mediaRecorder != null) {
-            mediaRecorder.stop();
-            mediaRecorder.reset();
-            mediaRecorder.release();
-            mediaRecorder = null;
-            isRecording = false;
+            try {
+                mediaRecorder.stop();
+                mediaRecorder.release();
+                mediaRecorder = null;
+            } catch (RuntimeException e) {
+                // RuntimeException may be thrown if the MediaRecorder is in an invalid state
+                e.printStackTrace();
+            }
         }
     }
 
-    public boolean isRecording(){
-        return isRecording;
-    }
-
-    public void setOutputDir(File outputDir) {
-        this.outputDir = outputDir;
-    }
-
-    private String generateFileName(){
-        // Get the current timestamp
-        LocalDateTime currentTime = LocalDateTime.now();
-        // Define the format for the timestamp
-        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd_HHmmss");
-        // Return the timestamp as a string
-        return currentTime.format(formatter);
-    }
-
     public void playAudio() {
         MediaPlayer mp = new MediaPlayer();
         try {
-            mp.setDataSource(context.getFilesDir() + "/audio.3gp");
+            mp.setDataSource(context.getFilesDir() + "/audio.mp3");
             mp.prepare();
             mp.start();
         } catch (Exception e) {
             e.printStackTrace();
         }
     }
+
+
+    public void deleteRecording(){
+        File file = new File(context.getFilesDir() + "/audio.mp3");
+        if (file.exists()) {
+            file.delete();
+        }
+    }
 }

app/src/main/java/com/example/ueberwachungssystem/Detection/DetectionReport.java

@@ -9,26 +9,24 @@ public class DetectionReport {
     public String timeStamp;
     public String detectionType;
     public float detectedValue;
-    public boolean detectionState;
+    public String detectorID;
 
-    public DetectionReport(boolean detectionState, String detectionType, float detectedAmplitude) {
+    public DetectionReport(String detectorID, String detectionType, float detectedAmplitude) {
         this.timeStamp = String.valueOf(Calendar.getInstance().getTime());
         this.detectionType = detectionType;
         this.detectedValue = detectedAmplitude;
-        this.detectionState = detectionState;
-
-        //this.detectorID = detectorID;
+        this.detectorID = detectorID;
     }
 
 
     /** Get Detection Report in String format */
     public String toString() {
-        String state = "State: " + "[" + this.detectionState + "]";
         String time = "Time: " + "[" + this.timeStamp + "]";
         String type = "Type: " + "[" + this.detectionType + "]";
         String value = "Value: " + "[" + this.detectedValue + "]";
+        String id = "ID: " + "[" + this.detectorID + "]";
 
-        return String.join("\t", state, time, type, value);
+        return String.join("\t", time, type, value, id);
     }
 
     /** Debug Report */

app/src/main/java/com/example/ueberwachungssystem/Detection/Detector.java

@@ -1,18 +1,10 @@
 package com.example.ueberwachungssystem.Detection;
 
-import android.os.CountDownTimer;
-
 import androidx.annotation.NonNull;
 
 
 abstract public class Detector {
     private OnDetectionListener listener;
-    private boolean isDetecting = false;
-    private boolean extendViolation = false;
-
-    // Countdown parameters
-    private final int COUNTDOWN_TIME = 5000;          // milliseconds
-    private final int COUNTDOWN_POLLING_TIME = 100;   // milliseconds
 
     /** Constructor - takes context of current activity */
     public Detector() {}
@@ -26,46 +18,17 @@ abstract public class Detector {
         this.listener = listener;
     }
 
+
     /** Triggers onDetectionListener - call this to trigger violation/alarm */
-    public void reportViolation(String detectionType, float amplitude) {
+    public void reportViolation(String detectorID, String detectionType, float amplitude) {
         if (listener != null) {
-            if (!isDetecting) {
-                isDetecting = true;
-                DetectionReport detectionReport = new DetectionReport(true, detectionType, amplitude);
-                listener.onDetection(detectionReport);
-                startDetectionTimer(detectionType, amplitude);
-            } else {
-                extendViolation = true;
-            }
+            DetectionReport detectionReport = new DetectionReport(detectorID, detectionType, amplitude);
+            listener.onDetection(detectionReport);
         } else {
-            isDetecting = false;
-            extendViolation = false;
+            throw new IllegalStateException("No listener set for violation reporting");
         }
     }
 
-    private void startDetectionTimer(String detectionType, float amplitude) {
-        isDetecting = true;
-        new CountDownTimer((long) COUNTDOWN_TIME, COUNTDOWN_POLLING_TIME) {
-            @Override
-            public void onTick(long millisUntilFinished) {
-                if (extendViolation) {
-                    extendViolation = false;
-                    startDetectionTimer(detectionType, amplitude);
-                    this.cancel();
-                }
-            }
-            @Override
-            public void onFinish() {
-                isDetecting = false;
-                DetectionReport detectionReport = new DetectionReport(false, detectionType, amplitude);
-                listener.onDetection(detectionReport);
-            }
-        }.start();
-    }
-
-    public void extendViolation(){
-        this.extendViolation = true;
-    }
 
     /** Starts Detection (abstract method: needs to be overridden in child class) */
     public abstract void startDetection();

app/src/main/java/com/example/ueberwachungssystem/Detection/VideoDetector.java

@@ -2,24 +2,20 @@ package com.example.ueberwachungssystem.Detection;
 
 import android.Manifest;
 import android.annotation.SuppressLint;
-import android.app.Activity;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.graphics.Bitmap;
 import android.graphics.ImageFormat;
 import android.media.Image;
-import android.os.CountDownTimer;
-import android.util.Log;
+import android.util.Size;
 import android.view.Surface;
-import android.widget.ImageView;
 import android.widget.Toast;
+import android.widget.VideoView;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.camera.core.CameraSelector;
 import androidx.camera.core.ExperimentalGetImage;
 import androidx.camera.core.ImageAnalysis;
-import androidx.camera.core.ImageProxy;
 import androidx.camera.core.Preview;
 import androidx.camera.core.VideoCapture;
 import androidx.camera.lifecycle.ProcessCameraProvider;
@@ -30,28 +26,23 @@ import androidx.lifecycle.LifecycleOwner;
 
 import com.google.common.util.concurrent.ListenableFuture;
 
-import org.opencv.android.OpenCVLoader;
-import org.opencv.android.Utils;
-import org.opencv.core.Core;
-import org.opencv.core.CvType;
-import org.opencv.core.Mat;
-import org.opencv.core.MatOfPoint;
-import org.opencv.core.Scalar;
-import org.opencv.core.Size;
-import org.opencv.imgproc.Imgproc;
-
 import java.io.File;
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
 import java.util.concurrent.ExecutionException;
 
 
 /**
  * Video Detector inherits some methods from abstract Detector class (more info there)
+ *
+ *
  * USE FROM MAIN ACTIVITY:
+ *
  * VideoDetector vd = new VideoDetector(this);
+ * vd.setPreview(previewView);  //THIS IS OPTIONAL!
+ * vd.setOnDetectionListener(new Detector.OnDetectionListener{...});
+ * vd.startDetection();
+ * vd.stopDetection
+ *
  * */
 
 
@@ -60,382 +51,207 @@ public class VideoDetector extends Detector {
 
     // Calling Activity
     private final Context context;
-
-    // Permission handling
-    private static final int PERMISSION_REQUEST_CODE = 3691;
-
     // Camera Provider
     private ProcessCameraProvider cameraProvider;
-    private final ImageAnalysis imageAnalysis;
-    private final VideoCapture videoCapture;
-    private final Preview preview;
-
-    // Logic
-    private boolean isDetecting = false;
-    private boolean isRecording = false;
-    private boolean allowReportViolation = false;
-
-    // Image Processing
-    private Mat previousImage = null;
-
-    // Debugging
-    private ImageView inputImageView = null;
-    private ImageView outputImageView = null;
+    private Boolean isDetectionRunning = false;
+    // Preview Camera Image
+    private PreviewView previewView = null;
+    private VideoCapture videoCapture = null;
+    // Detect Violation
+    private static final float PIXEL_THRESHOLD = 30f;  // Luminosity (brightness channel of YUV_420_888)
+    private static final float ALARM_THRESHOLD = 0.2f;   // Percent of pixels changed
+    private ByteBuffer previousBuffer = null;
 
 
-    // Recording
-    private final String outputName = "video.mp4";
-
-
-    // Parameters
-    private static final float ALARM_THRESHOLD = 0.5f;   // Percent of pixels changed
-    private static final long START_DELAY = 20000;   // milliseconds
-    private static final android.util.Size IMAGE_RES = new android.util.Size(640, 480);
-
-
-    private enum UseCase {
-        ImageAnalysis,
-        Preview,
-        VideoCapture
-    };
-
-
-    /** Constructor */
+    /**
+     * Constructor
+     * @param context: the context of calling activity (usually "this")
+     * */
     public VideoDetector(Context context) {
         super();
         this.context = context;
-        this.imageAnalysis = setupImageAnalysis();
-        this.videoCapture = setupVideoCapture();
-        this.preview = new Preview.Builder().build();
-    }
-
-    /** Get State of the Detector */
-    public boolean isRunning() {
-        return isDetecting;
     }
 
 
-    /** Starts the Video Detection */
+    /**
+     *  Starts the Video Detection
+     * */
     @Override
     public void startDetection() {
-        // Check States
-        if (isDetecting)
+        if (isDetectionRunning)
             return;
-        // Return On Request Permissions
-        if (!hasPermissions()) {
-            getPermissions();
-            return;
-        }
-        // Open CV startup check
-        if (!OpenCVLoader.initDebug()) {
-            Log.e("OpenCV", "Unable to load OpenCV!");
-            return;
-        } else
-            Log.d("OpenCV", "OpenCV loaded Successfully!");
-        // Get Process Camera Provider and start
+        // Request Camera Provider
         final ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(context);
+        //Check for Camera availability
         cameraProviderFuture.addListener(() -> {
             try {
                 cameraProvider = cameraProviderFuture.get();
-                isDetecting = true;
-                bindCameraProvider(UseCase.ImageAnalysis);
-            } catch (ExecutionException | InterruptedException e) {}
+                bindAnalysis(cameraProvider);
+                isDetectionRunning = true;
+                previousBuffer = null;
+            } catch (ExecutionException | InterruptedException e) {
+                // No errors need to be handled for this Future. This should never be reached.
+            }
         }, ContextCompat.getMainExecutor(context));
-
-        startViolationTimer();
     }
 
-    /** Stops the Video Detection */
+
+    /**
+     * Stops the Video Detection
+     * */
     @Override
     public void stopDetection() {
-        if (!isDetecting || imageAnalysis == null)
+        if (!isDetectionRunning)
             return;
-        cameraProvider.unbind(imageAnalysis);
-        isDetecting = false;
-        allowReportViolation = false;
-    }
-
-    /** Permission handling */
-    private boolean hasPermissions() {
-        return ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED &&
-                ContextCompat.checkSelfPermission(context, Manifest.permission.RECORD_AUDIO) == PackageManager.PERMISSION_GRANTED;
-    }
-    private void getPermissions() {
-        if (!hasPermissions())
-            ActivityCompat.requestPermissions((Activity) context, new String[]{android.Manifest.permission.CAMERA, Manifest.permission.RECORD_AUDIO}, PERMISSION_REQUEST_CODE);
-    }
-
-
-
-    /** Binds the Luminosity Analyzer (configure and run Analysis) */
-    private void bindCameraProvider(UseCase useCase) {
-        // Specify which Camera to use
-        CameraSelector cameraSelector = new CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build();
         cameraProvider.unbindAll();
-        cameraProvider.bindToLifecycle((LifecycleOwner) context, cameraSelector, imageAnalysis, videoCapture);
+        isDetectionRunning = false;
     }
 
 
-    /** Start delay until Violation Report is allowed */
-    private void startViolationTimer() {
-        new CountDownTimer((long) (START_DELAY), 100) {
-            @Override
-            public void onTick(long millisUntilFinished) {
-            }
-            @Override
-            public void onFinish() {
-                allowReportViolation = true;
-            }
-        }.start();
+    /**
+     * Set PreviewView to show video feed while detecting
+     * this is optional and does not need to be called
+     * */
+    public void setPreviewView(PreviewView previewView) {
+        this.previewView = previewView;
     }
 
 
-    private ImageAnalysis setupImageAnalysis() {
+    /**
+     * Binds the Luminosity Analyzer (configure and run Analysis)
+     * @param cameraProvider: CameraProvider of Context passed by Constructor
+     * */
+    @SuppressLint("RestrictedApi")
+    private void bindAnalysis(@NonNull ProcessCameraProvider cameraProvider) {
         // Configure and create Image Analysis
         ImageAnalysis.Builder builder = new ImageAnalysis.Builder();
-        builder.setTargetResolution(IMAGE_RES);
+        builder.setTargetResolution(new Size(640, 480));
         builder.setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST);
         builder.setOutputImageFormat(ImageAnalysis.OUTPUT_IMAGE_FORMAT_YUV_420_888);
         ImageAnalysis imageAnalysis = builder.build();
+
         // Set Analyzer
         imageAnalysis.setAnalyzer(ContextCompat.getMainExecutor(context), imageProxy -> {
             if (imageProxy.getFormat() == ImageFormat.YUV_420_888) {
                 Image image = imageProxy.getImage();
                 assert image != null;
 
-                // Violation Handling
-                Mat processed = processImage(imageProxy);
-                int n = OpenCVHelper.countNonZeroPixels(processed);
-                int pixelCount = image.getWidth() * image.getHeight();
-                float percentChanged = (float) n / pixelCount;
+                // Changed Pixel Detection
+                int pixelChanged = getChangedPixelCount(image);
+                int width = image.getWidth();
+                int height = image.getHeight();
 
-                // Violation Condition
-                if (percentChanged * 100 > ALARM_THRESHOLD) {
-                    if (allowReportViolation)
-                        reportViolation("Video", n);
-                }
+                float percentPixelChanged = (float) 100f * pixelChanged / (width * height);
+
+                if (percentPixelChanged > ALARM_THRESHOLD)
+                    reportViolation("0", "Video", percentPixelChanged);
             }
             imageProxy.close();
         });
-        return imageAnalysis;
-    }
+        // Create Preview
+        Preview preview = new Preview.Builder().build();
+        // Specify which Camera to use
+        CameraSelector cameraSelector = new CameraSelector.Builder().requireLensFacing(CameraSelector.LENS_FACING_BACK).build();
+        // Update PreviewView if set
+        if (previewView != null)
+            preview.setSurfaceProvider(previewView.getSurfaceProvider());
 
-    @SuppressLint("RestrictedApi")
-    private VideoCapture setupVideoCapture() {
-        return new VideoCapture.Builder()
+        videoCapture = new VideoCapture.Builder()
+                .setVideoFrameRate(30)
                 .setTargetRotation(Surface.ROTATION_0)
                 .build();
+
+
+        cameraProvider.bindToLifecycle((LifecycleOwner) context, cameraSelector, imageAnalysis, videoCapture);
     }
 
+
     @SuppressLint("RestrictedApi")
     public void startRecording() {
-        // Check States
-        if (isRecording){
-            extendViolation();
+
+        File dir = context.getFilesDir();
+        String filename = "recording";
+        String vidFilePath = dir.getAbsolutePath() + "/" + filename + ".mp4";
+        File vidFile = new File(vidFilePath);
+
+        if (ActivityCompat.checkSelfPermission(context, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
+            // TODO: Consider calling
+            //    ActivityCompat#requestPermissions
+            // here to request the missing permissions, and then overriding
+            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
+            //                                          int[] grantResults)
+            // to handle the case where the user grants the permission. See the documentation
+            // for ActivityCompat#requestPermissions for more details.
             return;
         }
+        videoCapture.startRecording(
+                new VideoCapture.OutputFileOptions.Builder(vidFile).build(),
+                context.getMainExecutor(),
+                new VideoCapture.OnVideoSavedCallback() {
+                    @Override
+                    public void onVideoSaved(@NonNull VideoCapture.OutputFileResults outputFileResults) {
+                        Toast.makeText(context, "recording saved", Toast.LENGTH_SHORT).show();
+                    }
 
-        // Return On Request Permissions
-        if (!hasPermissions()) {
-            getPermissions();
-            return;
-        }
-
-        final ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(context);
-        cameraProviderFuture.addListener(() -> {
-            try {
-                cameraProvider = cameraProviderFuture.get();
-                isRecording = true;
-                bindCameraProvider(UseCase.VideoCapture);
-
-                File vidFile = new File(context.getFilesDir() + "/" + outputName);
-                if (ActivityCompat.checkSelfPermission(context, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
-                    return;
+                    @Override
+                    public void onError(int videoCaptureError, @NonNull String message, @Nullable Throwable cause) {
+                        Toast.makeText(context, "recording failed", Toast.LENGTH_SHORT).show();
+                    }
                 }
-                videoCapture.startRecording(
-                        new VideoCapture.OutputFileOptions.Builder(vidFile).build(),
-                        context.getMainExecutor(),
-                        new VideoCapture.OnVideoSavedCallback() {
-                            @Override
-                            public void onVideoSaved(@NonNull VideoCapture.OutputFileResults outputFileResults) {
-                                isRecording = false;
-                                Toast.makeText(context, "recording saved", Toast.LENGTH_SHORT).show();
-                            }
-                            @Override
-                            public void onError(int videoCaptureError, @NonNull String message, @Nullable Throwable cause) {
-                                isRecording = false;
-                                Toast.makeText(context, "recording failed", Toast.LENGTH_SHORT).show();
-                            }
-                        }
-                );
-            } catch (ExecutionException | InterruptedException e) {}
-        }, ContextCompat.getMainExecutor(context));
+        );
     }
 
     @SuppressLint("RestrictedApi")
     public void stopRecording(){
         videoCapture.stopRecording();
-        cameraProvider.unbind(videoCapture);
-        isRecording = false;
     }
 
-    /** Process Image to be used for Motion Detection */
-    private Mat processImage(ImageProxy imageProxy){
-        if (imageProxy == null)
-            return null;
+    /**
+     * Calculate Amount of Pixels changed using a threshold
+     * @param image
+     * */
+    private int getChangedPixelCount(Image image) {
+        Image.Plane[] planes = image.getPlanes();
+        ByteBuffer buffer = planes[0].getBuffer();
 
-        // Image Transformation
-        Mat imageMat = OpenCVHelper.extractYChannel(imageProxy);
-
-        // Show Input Image
-        if (inputImageView != null)
-            OpenCVHelper.debugMat(imageMat, inputImageView);
-
-        // Preprocess Image
-        Mat preprocessed = imageMat;
-        preprocessed = OpenCVHelper.addGaussianBlur(preprocessed, new Size(21, 21));
-        preprocessed = OpenCVHelper.addBlur(preprocessed, new Size(3, 3));
-
-        if (previousImage == null) {
-            previousImage = preprocessed;
-            return null;
+        if (previousBuffer == null) {
+            previousBuffer = ByteBuffer.allocate(buffer.capacity());
+            buffer.rewind();
+            previousBuffer.put(buffer);
+            previousBuffer.rewind();
+            return 0;
         }
 
-        // Process Image
-        Mat processed = preprocessed.clone();
-        processed = OpenCVHelper.thresholdPixels(processed, previousImage, 25);
-        processed = OpenCVHelper.dilateBinaryMat(processed, new Size(3,3));
-        processed = OpenCVHelper.dilateBinaryMat(processed, new Size(3,3));
-        processed = OpenCVHelper.thresholdContourArea(processed, 500);
+        int width = image.getWidth();
+        int height = image.getHeight();
 
-        // Output
-        previousImage = preprocessed.clone();
-        // Show Output Image
-        if (outputImageView != null)
-            OpenCVHelper.debugMat(processed, outputImageView);
-        return processed;
-    }
+        int yRowStride = image.getPlanes()[0].getRowStride();
+        int yPixelStride = image.getPlanes()[0].getPixelStride();
 
-    public void debugProcessing(@NonNull ImageView inputImageView, @NonNull ImageView outputImageView){
-        this.inputImageView = inputImageView;
-        this.outputImageView = outputImageView;
-    }
+        int changedPixelCount = 0;
 
-    public void setPreviewView(@NonNull PreviewView previewView) {
-        // Create Preview
-        if (this.preview != null)
-            this.preview.setSurfaceProvider(previewView.getSurfaceProvider());
-    }
-
-
-
-    private static class OpenCVHelper{
-        private OpenCVHelper() {}
-
-        /** OpenCV helper methods **/
-        private static Mat addGaussianBlur(Mat inputMat, Size kernelSize){
-            Mat outputMat = new Mat();
-            Imgproc.GaussianBlur(inputMat, outputMat, kernelSize, 0);
-            return outputMat;
-        }
-
-        private static Mat addBlur(Mat inputMat, Size kernelSize){
-            Mat outputMat = new Mat();
-            Imgproc.blur(inputMat, outputMat, kernelSize);
-            return outputMat;
-        }
-
-        private static Mat extractYChannel(@NonNull ImageProxy imgProxy) {
-            Image img = imgProxy.getImage();
-
-            assert img != null;
-            ByteBuffer yBuffer = img.getPlanes()[0].getBuffer();
-            byte[] yData = new byte[yBuffer.remaining()];
-            yBuffer.get(yData);
-
-            Mat yMat = new Mat(img.getHeight(), img.getWidth(), CvType.CV_8UC1);
-            yMat.put(0, 0, yData);
-
-            return yMat;
-        }
-
-        private static Mat thresholdPixels(Mat inputMat, Mat previousImage, int threshold){
-            Mat diffImage = new Mat();
-            Core.absdiff(inputMat, previousImage, diffImage);
-            Mat binaryMat = new Mat();
-            Imgproc.threshold(diffImage, binaryMat, threshold, 255, Imgproc.THRESH_BINARY);
-            return binaryMat;
-        }
-
-        private static Mat imageProxyToGrayscaleMat(ImageProxy imageProxy) {
-            // Step 1: Extract the image data from ImageProxy
-            ImageProxy.PlaneProxy[] planes = imageProxy.getPlanes();
-            ByteBuffer yBuffer = planes[0].getBuffer();
-            byte[] yData = new byte[yBuffer.remaining()];
-            yBuffer.get(yData);
-
-            // Step 2: Convert the image data to NV21 format
-            int width = imageProxy.getWidth();
-            int height = imageProxy.getHeight();
-            byte[] nv21Data = new byte[width * height * 3 / 2];
-            // Assuming the image format is YUV_420_888
-            System.arraycopy(yData, 0, nv21Data, 0, yData.length);
-            for (int i = yData.length; i < nv21Data.length; i += 2) {
-                nv21Data[i] = yData[i + 1];
-                nv21Data[i + 1] = yData[i];
+        // Count changed pixels
+        for (int y = 0; y < height; ++y) {
+            for (int x = 0; x < width; x++) {
+                int index = (y * yRowStride) + (x * yPixelStride);
+                int luminosity = (buffer.get(index) & 0xff);
+                int previousLuminosity = (previousBuffer.get(index) & 0xff);
+                int diff = Math.abs(luminosity - previousLuminosity);
+                if (diff > PIXEL_THRESHOLD)
+                    changedPixelCount++;
             }
-
-            // Step 3: Create a grayscale Mat from the NV21 data
-            Mat grayscaleMat = new Mat(height, width, CvType.CV_8UC1);
-            grayscaleMat.put(0, 0, nv21Data);
-
-            return grayscaleMat;
         }
 
+        // Reset and copy Byte Buffer
+        buffer.rewind();
+        previousBuffer.rewind();
+        previousBuffer.put(buffer);
 
-        private static Mat thresholdContourArea(Mat inputMat, float areaThreshold){
-            List<MatOfPoint> contours = new ArrayList<>();
-            Mat hierarchy = new Mat();
-            Imgproc.findContours(inputMat, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
-
-            Mat outputMat = new Mat(inputMat.size(), inputMat.type(), new Scalar(0));
-            // Iterate over the contours and draw only the larger contours on the outputMat
-            for (MatOfPoint contour : contours) {
-                double contourArea = Imgproc.contourArea(contour);
-                if (contourArea > areaThreshold) {
-                    Imgproc.drawContours(outputMat, Collections.singletonList(contour), 0, new Scalar(255), -1);
-                }
-            }
-            // Apply the outputMat as a mask to the dilatedImage
-            Mat maskedImage = new Mat();
-            inputMat.copyTo(maskedImage, outputMat);
-            return outputMat;
-        }
-
-        private static Mat dilateBinaryMat(Mat inputMat, Size kernelSize){
-            Mat dilatedMat = new Mat();
-            Mat kernel = Imgproc.getStructuringElement(Imgproc.MORPH_ELLIPSE, kernelSize);
-            Imgproc.dilate(inputMat, dilatedMat, kernel);
-            return dilatedMat;
-        }
-
-        private static int countNonZeroPixels(Mat inputImage) {
-            if (inputImage != null)
-                return Core.countNonZero(inputImage);
-            else
-                return 0;
-        }
-
-
-        private static void debugMat(Mat mat, ImageView imageView) {
-            if (imageView == null || mat == null)
-                return;
-
-            Bitmap bitmap = Bitmap.createBitmap(mat.cols(), mat.rows(), Bitmap.Config.ARGB_8888);
-            Utils.matToBitmap(mat, bitmap);
-
-            // Display the bitmap in an ImageView
-            imageView.setImageBitmap(bitmap);
-        }
+        return changedPixelCount;
     }
-}
+
+    public void playVideo(VideoView videoView) {
+        videoView.setVideoPath(context.getFilesDir() + "/recording.mp4");
+        videoView.start();
+    }
+}

app/src/main/java/com/example/ueberwachungssystem/DetectionRecorder.java

@@ -0,0 +1,147 @@
+package com.example.ueberwachungssystem;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.media.MediaPlayer;
+import android.view.Surface;
+import android.widget.Toast;
+import android.widget.VideoView;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.camera.core.CameraSelector;
+import androidx.camera.core.Preview;
+import androidx.camera.core.VideoCapture;
+import androidx.camera.lifecycle.ProcessCameraProvider;
+import androidx.camera.view.PreviewView;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+import androidx.lifecycle.LifecycleOwner;
+
+import com.google.common.util.concurrent.ListenableFuture;
+
+import java.io.File;
+import java.util.concurrent.ExecutionException;
+
+public class DetectionRecorder {
+
+    private final Context context;
+    private ProcessCameraProvider cameraProvider;
+    private VideoCapture videoCapture = null;
+    private PreviewView previewView = null;
+    private boolean isRunning = false;
+    private boolean isVideoPlaying = false;
+
+
+    // Constructor
+    public DetectionRecorder(Context context) {
+        this.context = context;
+    }
+
+
+    public void start() {
+        if (isRunning)
+            return;
+        isRunning = true;
+
+        // Request Camera Provider
+        final ListenableFuture<ProcessCameraProvider> cameraProviderFuture = ProcessCameraProvider.getInstance(context);
+        //Check for Camera availability
+        cameraProviderFuture.addListener(() -> {
+            try {
+                cameraProvider = cameraProviderFuture.get();
+                startCameraX(cameraProvider);
+            } catch (ExecutionException | InterruptedException e) {
+                // No errors need to be handled for this Future. This should never be reached.
+            }
+        }, ContextCompat.getMainExecutor(context));
+    }
+
+
+    @SuppressLint("RestrictedApi")
+    public void stop() {
+        if (!isRunning)
+            return;
+
+        videoCapture.stopRecording();
+        cameraProvider.unbind(videoCapture);
+        isRunning = false;
+    }
+
+    @SuppressLint("RestrictedApi")
+    private void startCameraX(ProcessCameraProvider cameraProvider) {
+        //cameraProvider.unbindAll();
+
+        CameraSelector cameraSelector = new CameraSelector.Builder()
+                .requireLensFacing(CameraSelector.LENS_FACING_BACK)
+                .build();
+
+        // Preview Use Case
+        Preview preview = new Preview.Builder().build();
+        if (previewView != null)
+            preview.setSurfaceProvider(previewView.getSurfaceProvider());
+
+        // Video Capture Use Case
+        videoCapture = new VideoCapture.Builder()
+                .setVideoFrameRate(30)
+                .setTargetRotation(Surface.ROTATION_0)
+                .build();
+
+        cameraProvider.bindToLifecycle((LifecycleOwner) context, cameraSelector, preview, videoCapture);
+
+
+        File dir = context.getFilesDir();
+        String filename = "recording";
+        String vidFilePath = dir.getAbsolutePath() + "/" + filename + ".mp4";
+        File vidFile = new File(vidFilePath);
+
+        if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
+            // TODO: Consider calling
+            //    ActivityCompat#requestPermissions
+            // here to request the missing permissions, and then overriding
+            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
+            //                                          int[] grantResults)
+            // to handle the case where the user grants the permission. See the documentation
+            // for ActivityCompat#requestPermissions for more details.
+            return;
+        }
+        videoCapture.startRecording(
+                new VideoCapture.OutputFileOptions.Builder(vidFile).build(),
+                context.getMainExecutor(),
+                new VideoCapture.OnVideoSavedCallback() {
+                    @Override
+                    public void onVideoSaved(@NonNull VideoCapture.OutputFileResults outputFileResults) {
+                        Toast.makeText(context, "recording saved", Toast.LENGTH_SHORT).show();
+                    }
+                    @Override
+                    public void onError(int videoCaptureError, @NonNull String message, @Nullable Throwable cause) {
+                        Toast.makeText(context, "recording failed", Toast.LENGTH_SHORT).show();
+                    }
+                }
+        );
+    }
+
+    /** Set PreviewView to show Image */
+    public void setPreviewView(PreviewView previewView) {
+        this.previewView = previewView;
+    }
+
+    private void playAudio() {
+        MediaPlayer mp = new MediaPlayer();
+        try {
+            mp.setDataSource(context.getFilesDir() + "/audio.gpp");
+            mp.prepare();
+            mp.start();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void playVideo(VideoView videoView) {
+        if (isVideoPlaying)
+            return;
+        videoView.setVideoPath(context.getFilesDir() + "/recording.mp4");
+        videoView.start();
+    }
+}

app/src/main/java/com/example/ueberwachungssystem/DetectionReport.java

@@ -1,36 +0,0 @@
-package com.example.ueberwachungssystem;
-
-import android.util.Log;
-
-import java.util.Calendar;
-
-/** Detection Report Class */
-public class DetectionReport {
-    public String timeStamp;
-    public String detectionType;
-    public float detectedValue;
-    public String detectorID;
-
-    public DetectionReport(String detectorID, String detectionType, float detectedAmplitude) {
-        this.timeStamp = String.valueOf(Calendar.getInstance().getTime());
-        this.detectionType = detectionType;
-        this.detectedValue = detectedAmplitude;
-        this.detectorID = detectorID;
-    }
-
-
-    /** Get Detection Report in String format */
-    public String toString() {
-        String time = "Time: " + "[" + this.timeStamp + "]";
-        String type = "Type: " + "[" + this.detectionType + "]";
-        String value = "Value: " + "[" + this.detectedValue + "]";
-        String id = "ID: " + "[" + this.detectorID + "]";
-
-        return String.join("\t", time, type, value, id);
-    }
-
-    /** Debug Report */
-    public void log(String tag) {
-        Log.d(tag, this.toString());
-    }
-}

app/src/main/java/com/example/ueberwachungssystem/Detector.java

@@ -1,40 +0,0 @@
-package com.example.ueberwachungssystem;
-
-import android.app.Activity;
-import android.content.Context;
-import androidx.annotation.NonNull;
-
-
-abstract public class Detector {
-    private OnDetectionListener listener;
-
-    /** Constructor - takes context of current activity */
-    public Detector(Context context) {};
-
-
-    /** On Detection Listener - runs when violation is reported */
-    public interface OnDetectionListener {
-        void onDetection(@NonNull DetectionReport detectionReport);
-    }
-    public void setOnDetectionListener(@NonNull OnDetectionListener listener) {
-        this.listener = listener;
-    }
-
-
-    /** Triggers onDetectionListener - call this to trigger violation/alarm */
-    private void reportViolation(String detectorID, String detectionType, float amplitude) {
-        if (listener != null) {
-            DetectionReport detectionReport = new DetectionReport(detectorID, detectionType, amplitude);
-            listener.onDetection(detectionReport);
-        } else {
-            throw new IllegalStateException("No listener set for violation reporting");
-        }
-    }
-
-
-    /** Starts Detection (abstract method: needs to be overridden in child class) */
-    public abstract void startDetection();
-
-    /** Stops Detection (abstract method: needs to be overridden in child class) */
-    public abstract void stopDetection();
-}

app/src/main/java/com/example/ueberwachungssystem/MainActivity.java

@@ -2,77 +2,119 @@ package com.example.ueberwachungssystem;
 
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
-import androidx.camera.core.ExperimentalGetImage;
 import androidx.camera.view.PreviewView;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+import androidx.camera.core.ExperimentalGetImage;
 
+import android.Manifest;
+import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.View;
-import android.widget.ImageView;
 import android.widget.TextView;
+import android.widget.Toast;
 import android.widget.ToggleButton;
+import android.widget.VideoView;
 
 import com.example.ueberwachungssystem.Detection.DetectionReport;
 import com.example.ueberwachungssystem.Detection.Detector;
 import com.example.ueberwachungssystem.Detection.VideoDetector;
-import com.example.ueberwachungssystem.logger.Logger;
-import com.jjoe64.graphview.GraphView;
+
+import java.io.File;
+import java.util.Arrays;
 
 @ExperimentalGetImage
 public class MainActivity extends AppCompatActivity {
 
+    private static final int PERMISSION_REQUEST_CODE = 111;
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-
-        ImageView inputImageView = findViewById(R.id.inputImageView);
-        ImageView outputImageView = findViewById(R.id.outputImageView);
+        TextView textView = findViewById(R.id.textView);
+        VideoView videoView = findViewById(R.id.videoView);
         PreviewView previewView = findViewById(R.id.previewView);
 
-
-        // Mic stuff
-        TextView textView= (TextView) findViewById(R.id.textView); //Set textview for showing logged content
-        Logger logger = new Logger(this.getClass().getSimpleName(), textView, "");
-        GraphView graph = (GraphView) findViewById(R.id.graph);
-        MicrophoneDetector mic = new MicrophoneDetector(this, logger, graph);
-        mic.startDetection();
+        File directory = getFilesDir();
 
 
+        AudioRecorder ar = new AudioRecorder(this);
 
-        AudioRecorder audioRecorder = new AudioRecorder(this);
 
-        // video Stuff
-        VideoDetector vd = new VideoDetector(this);
-        //vd.setPreviewView(previewView);
-        vd.debugProcessing(inputImageView, outputImageView);
-        vd.setOnDetectionListener(new Detector.OnDetectionListener() {
+        //DetectionRecorder detectionRecorder = new DetectionRecorder(this);
+        //detectionRecorder.setPreviewView(previewView);
+
+        ToggleButton toggleButton = findViewById(R.id.previewButton);
+        ToggleButton toggleButton2 = findViewById(R.id.toggleButton2);
+
+        toggleButton.setOnClickListener(new View.OnClickListener() {
             @Override
-            public void onDetection(@NonNull DetectionReport detectionReport) {
-                Log.d("onDetection", detectionReport.toString());
+            public void onClick(View v) {
+                getRecordVideoAccess();
+                File[] files = directory.listFiles();
+                textView.setText(Arrays.toString(files));
+
+                if (isRecordVideoAllowed() && toggleButton.isChecked())
+                {
+                    ar.startRecording();
+                    //vd.startRecording();
+                    //vd.playVideo(videoView);
+                    //detectionRecorder.playVideo(videoView);
+                    //detectionRecorder.start();
+                }
+                else {
+                    ar.stopRecording();
+                    //vd.stopRecording();
+
+                    //detectionRecorder.stop();
+                }
             }
         });
-        vd.startDetection();
 
-
-        ToggleButton toggleButton = findViewById(R.id.toggleButton);
-        toggleButton.setOnClickListener(new View.OnClickListener() {
+        toggleButton2.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 if (toggleButton.isChecked())
                 {
-                    //vd.startDetection();
-                    vd.startRecording();
-                    audioRecorder.startRecording();
-
+                    ar.playAudio();
                 }
                 else {
-                    //vd.stopDetection();
-                    vd.stopRecording();
-                    audioRecorder.stopRecording();
+                    ar.deleteRecording();
                 }
             }
         });
     }
+
+    private boolean isRecordVideoAllowed() {
+        return ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED &&
+                ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) == PackageManager.PERMISSION_GRANTED;
+    }
+
+    private void getRecordVideoAccess() {
+        if (!isRecordVideoAllowed()) {
+            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA, Manifest.permission.RECORD_AUDIO}, PERMISSION_REQUEST_CODE);
+        }
+    }
+
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+
+        if (requestCode == PERMISSION_REQUEST_CODE && grantResults.length > 0) {
+
+            boolean cameraRights = grantResults[0] == PackageManager.PERMISSION_GRANTED;
+            boolean recordAudioRights = grantResults[1] == PackageManager.PERMISSION_GRANTED;
+
+            if (cameraRights && recordAudioRights) {
+                Toast.makeText(this, "permissions granted", Toast.LENGTH_LONG).show();
+            } else {
+                Toast.makeText(this, "permissions denied", Toast.LENGTH_LONG).show();
+            }
+        }
+    }
 }

app/src/main/java/com/example/ueberwachungssystem/MicrophoneDetector.java

@@ -1,445 +0,0 @@
-package com.example.ueberwachungssystem;
-
-import static java.lang.Math.*;
-
-import android.Manifest;
-import android.app.Activity;
-import android.content.Context;
-import android.content.pm.PackageManager;
-import android.media.AudioFormat;
-import android.media.AudioRecord;
-import android.media.MediaRecorder;
-import android.os.AsyncTask;
-
-import androidx.core.app.ActivityCompat;
-import androidx.core.content.ContextCompat;
-
-import com.example.ueberwachungssystem.Signalverarbeitung.Complex;
-import com.example.ueberwachungssystem.Signalverarbeitung.FFT;
-import com.example.ueberwachungssystem.logger.Logger;
-import com.jjoe64.graphview.GraphView;
-import com.jjoe64.graphview.series.DataPoint;
-import com.jjoe64.graphview.series.LineGraphSeries;
-
-public class MicrophoneDetector extends Detector {
-    /**
-     * Constructor - takes context of current activity
-     *
-     * @param context
-     */
-
-    private static final int RECHTEANFORDERUNG_MIKROFON = 1;
-
-    private AufnahmeTask aufnahmeTask;
-    public boolean armed = false;
-    public int Schwellwert_Alarm = 100;
-    GraphView graph;
-
-    Logger logger;
-    private Activity MainActivityForClass;
-
-    public MicrophoneDetector(Context context, Logger MainLogger, GraphView MainGraph) {
-        super(context);
-        MainActivityForClass = (Activity) context;
-        logger = MainLogger; //Class uses the same logger as the MainActivity
-        logger.log(this.getClass().getSimpleName() + ".onCreate");
-        graph = MainGraph;
-
-        if (!istZugriffAufMikrofonErlaubt()) {
-            zugriffAufMikrofonAnfordern();
-        }
-    }
-
-    @Override
-    public void startDetection() {
-        logger.log(this.getClass().getSimpleName() + ".startDetection");
-
-        if (!istZugriffAufMikrofonErlaubt()) {
-            zugriffAufMikrofonAnfordern();
-        }
-        if (istZugriffAufMikrofonErlaubt()) {
-            aufnahmeTask = new AufnahmeTask();
-            aufnahmeTask.execute();
-        }
-    }
-
-    @Override
-    public void stopDetection() {
-        logger.log(this.getClass().getSimpleName() + ".stopDetection");
-        if (aufnahmeTask != null) {
-            aufnahmeTask.cancel(true);
-            // aufnahmeTask = null; // if aufnahmeTask = null, break in for loop would not work (Nullpointer Exception)
-        }
-    }
-
-    private boolean istZugriffAufMikrofonErlaubt() {
-        if (ContextCompat.checkSelfPermission(MainActivityForClass, android.Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
-            logger.log("Zugriff auf Mikrofon ist verboten.");
-            return false;
-        } else {
-            logger.log("Zugriff auf Mikrofon ist erlaubt.");
-            return true;
-        }
-    }
-
-    private void zugriffAufMikrofonAnfordern() {
-        ActivityCompat.requestPermissions(MainActivityForClass, new String[]{Manifest.permission.RECORD_AUDIO}, RECHTEANFORDERUNG_MIKROFON);
-    }
-
-    class AufnahmeTask extends AsyncTask<Long, Verarbeitungsergebnis, Void> {
-        private AudioRecord recorder;
-        private final int sampleRateInHz = 44100;
-        private final int channelConfig = AudioFormat.CHANNEL_IN_MONO;
-        private final int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
-        private int minPufferGroesseInBytes;
-        private int pufferGroesseInBytes;
-        private RingPuffer ringPuffer = new RingPuffer(10);
-        private float kalibierWert;
-        private DetectionReport detectionReport;
-
-        AufnahmeTask() {
-            minPufferGroesseInBytes = AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, audioFormat);
-            pufferGroesseInBytes = minPufferGroesseInBytes * 2;
-            if (ActivityCompat.checkSelfPermission(MainActivityForClass, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
-                // TODO: Consider calling
-                //    ActivityCompat#requestPermissions
-                // here to request the missing permissions, and then overriding
-                //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
-                //                                          int[] grantResults)
-                // to handle the case where the user grants the permission. See the documentation
-                // for ActivityCompat#requestPermissions for more details.
-                ActivityCompat.requestPermissions(MainActivityForClass, new String[]{Manifest.permission.RECORD_AUDIO}, RECHTEANFORDERUNG_MIKROFON);
-            }
-
-            recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, sampleRateInHz, channelConfig, audioFormat, pufferGroesseInBytes);
-
-//            textViewMinPufferGroesseInBytes.setText("" + minPufferGroesseInBytes);
-//            textViewPufferGroesseInBytes.setText("" + pufferGroesseInBytes);
-//            textViewAbtastrate.setText("" + recorder.getSampleRate());
-//            textViewAnzahlKanaele.setText("" + recorder.getChannelCount());
-
-            logger.log("Puffergroeße: "+ minPufferGroesseInBytes + " " + pufferGroesseInBytes);
-            logger.log("Recorder (SR, CH): "+ recorder.getSampleRate() + " " + recorder.getChannelCount());
-
-            int anzahlBytesProAbtastwert;
-            String s;
-            switch (recorder.getAudioFormat()) {
-                case AudioFormat.ENCODING_PCM_8BIT:
-                    s = "8 Bit PCM ";
-                    anzahlBytesProAbtastwert = 1;
-                    break;
-                case AudioFormat.ENCODING_PCM_16BIT:
-                    s = "16 Bit PCM";
-                    anzahlBytesProAbtastwert = 2;
-                    break;
-                case AudioFormat.ENCODING_PCM_FLOAT:
-                    s = "Float PCM";
-                    anzahlBytesProAbtastwert = 4;
-                    break;
-                default:
-                    throw new IllegalArgumentException();
-            }
-//            textViewAudioFormat.setText(s);
-
-            switch (recorder.getChannelConfiguration()) {
-                case AudioFormat.CHANNEL_IN_MONO:
-                    s = "Mono";
-                    break;
-                case AudioFormat.CHANNEL_IN_STEREO:
-                    s = "Stereo";
-                    anzahlBytesProAbtastwert *= 2;
-                    break;
-                case AudioFormat.CHANNEL_INVALID:
-                    s = "ungültig";
-                    break;
-                default:
-                    throw new IllegalArgumentException();
-            }
-//            textViewKanalKonfiguration.setText(s);
-            logger.log("Konfiguration: "+ s);
-
-            int pufferGroesseInAnzahlAbtastwerten = pufferGroesseInBytes / anzahlBytesProAbtastwert;
-            int pufferGroesseInMillisekunden = 1000 * pufferGroesseInAnzahlAbtastwerten / recorder.getSampleRate();
-
-//            textViewPufferGroesseInAnzahlAbtastwerte.setText("" + pufferGroesseInAnzahlAbtastwerten);
-//            textViewPufferGroesseInMillisekunden.setText("" + pufferGroesseInMillisekunden);
-        }
-
-        @Override
-        protected Void doInBackground(Long... params) {
-            recorder.startRecording();
-            short[] puffer = new short[pufferGroesseInBytes / 2];
-            long lastTime = System.currentTimeMillis();
-            float verarbeitungsrate = 0;
-            final int maxZaehlerZeitMessung = 10;
-            int zaehlerZeitMessung = 0;
-            int anzahlVerarbeitet = 0;
-            GleitenderMittelwert gleitenderMittelwert = new GleitenderMittelwert(0.3f);
-
-            //Kalibrierung
-            try {
-                Thread.sleep(3000);
-            } catch (InterruptedException e) {
-                e.printStackTrace();
-            }
-            int i = 0;
-            for (i = 0; i < 20; i++) {
-                int n = recorder.read(puffer, 0, puffer.length);
-                Verarbeitungsergebnis kalibrierErgebnis = verarbeiten(puffer, n);
-                kalibierWert += kalibrierErgebnis.maxAmp;
-                try {
-                    Thread.sleep(50);
-                } catch (InterruptedException e) {
-                    e.printStackTrace();
-                }
-            }
-            kalibierWert = kalibierWert/i;
-
-//            Complex[] zeitSignal = new Complex[puffer.length];
-//            for (int j = 0; j < puffer.length; j++) {
-//                zeitSignal[j] = new Complex(puffer[j], 0);
-//            }
-//            Complex[] spektrum = FFT.fft(zeitSignal);
-            double[] spektrum = calculateFFT(puffer);
-            DataPoint AddPoint;
-//            LineGraphSeries<DataPoint> series = new LineGraphSeries<DataPoint>(new DataPoint[]{});
-//            for (i = 0; i < spektrum.length; i++) {
-//                AddPoint = new DataPoint(i, spektrum[i]);
-//                series.appendData(AddPoint, true, spektrum.length);
-//            }
-//            graph.addSeries(series);
-            // logger.log(spektrum.toString());
-
-            for (; ; ) {
-                if (aufnahmeTask.isCancelled()) {
-                    break;
-                } else {
-                    int n = recorder.read(puffer, 0, puffer.length);
-                    Verarbeitungsergebnis ergebnis = verarbeiten(puffer, n);
-                    anzahlVerarbeitet += n;
-
-                    spektrum = calculateFFT(puffer);
-                    LineGraphSeries<DataPoint> newseries = new LineGraphSeries<DataPoint>(new DataPoint[]{});
-                    for (i = 0; i < spektrum.length; i++) {
-                        AddPoint = new DataPoint(i, spektrum[i]);
-                        newseries.appendData(AddPoint, true, spektrum.length);
-                    }
-                    graph.removeAllSeries();
-                    graph.addSeries(newseries);
-                    zaehlerZeitMessung++;
-                    if (zaehlerZeitMessung == maxZaehlerZeitMessung) {
-                        long time = System.currentTimeMillis();
-                        long deltaTime = time - lastTime;
-                        verarbeitungsrate = 1000.0f * anzahlVerarbeitet / deltaTime;
-                        verarbeitungsrate = gleitenderMittelwert.mittel(verarbeitungsrate);
-                        zaehlerZeitMessung = 0;
-                        anzahlVerarbeitet = 0;
-                        lastTime = time;
-                    }
-
-
-                    ergebnis.verarbeitungsrate = (int) verarbeitungsrate;
-                    publishProgress(ergebnis);
-
-                    try {
-                        Thread.sleep(100);
-                    } catch (InterruptedException e) {
-                        e.printStackTrace();
-                    }
-                }
-            }
-            recorder.release();
-            return null;
-        }
-
-        private Verarbeitungsergebnis verarbeiten(short[] daten, int n) {
-            String status;
-            short maxAmp = -1;
-            if (n == AudioRecord.ERROR_INVALID_OPERATION) {
-                status = "ERROR_INVALID_OPERATION";
-            } else if (n == AudioRecord.ERROR_BAD_VALUE) {
-                status = "ERROR_BAD_VALUE";
-            } else {
-                status = "OK";
-                short max = 0;
-                for (int i = 0; i < n; i++) {
-                    if (daten[i] > max) {
-                        max = daten[i];
-                        //max = 20 * log10(abs(daten[i]) / 32768);
-                    }
-                }
-
-                ringPuffer.hinzufuegen(max);
-                maxAmp = ringPuffer.maximum();
-                if (maxAmp <= Schwellwert_Alarm+kalibierWert) {
-                    armed = true;
-                }
-            }
-
-            return new Verarbeitungsergebnis(status, maxAmp, 0);
-        }
-
-        @Override
-        protected void onProgressUpdate(Verarbeitungsergebnis... progress) {
-            super.onProgressUpdate(progress);
-//            textViewMaxAmp.setText("" + progress[0].maxAmp);
-//            textViewVerarbeitungsrate.setText("" + progress[0].verarbeitungsrate);
-            float maxAmpPrint = round(20*log10(abs(progress[0].maxAmp/1.0)));
-            float kalibierWertPrint = round(20*log10(abs(kalibierWert)));
-            logger.overwriteLastlog("VR, Max, Kal:" + progress[0].verarbeitungsrate + ", " + maxAmpPrint
-            + " dB, " + kalibierWertPrint + " dB");
-
-            if (progress[0].maxAmp >= Schwellwert_Alarm+kalibierWert && armed == true) {
-                armed = false;
-                detectionReport = new DetectionReport("Mic1", "Audio", maxAmpPrint);
-                logger.log("");
-                logger.log("Alarm!");
-                logger.log(detectionReport.toString());
-                logger.log("");
-            }
-        }
-    }
-
-    private double[] calculateFFT(short[] zeitsignal)
-    {
-        byte signal[] = new byte[zeitsignal.length];
-        // loops through all the values of a Short
-        for (int i = 0; i < zeitsignal.length-1; i++) {
-            signal[i] = (byte) (zeitsignal[i]);
-            signal[i+1] = (byte) (zeitsignal[i] >> 8);
-        }
-
-        final int mNumberOfFFTPoints =1024;
-        double mMaxFFTSample;
-
-        double temp;
-        Complex[] y;
-        Complex[] complexSignal = new Complex[mNumberOfFFTPoints];
-        double[] absSignal = new double[mNumberOfFFTPoints/2];
-
-        for(int i = 0; i < mNumberOfFFTPoints; i++){
-            temp = (double)((signal[2*i] & 0xFF) | (signal[2*i+1] << 8)) / 32768.0F;
-            complexSignal[i] = new Complex(temp,0.0);
-        }
-
-        y = FFT.fft(complexSignal);
-
-        mMaxFFTSample = 0.0;
-        // mPeakPos = 0;
-        for(int i = 0; i < (mNumberOfFFTPoints/2); i++)
-        {
-            absSignal[i] = y[i].abs();
-//            absSignal[i] = Math.sqrt(Math.pow(y[i].re(), 2) + Math.pow(y[i].im(), 2));
-//            if(absSignal[i] > mMaxFFTSample)
-//            {
-//                mMaxFFTSample = absSignal[i];
-//                // mPeakPos = i;
-//            }
-        }
-
-        return absSignal;
-
-    }
-
-    class Verarbeitungsergebnis {
-        String status;
-        short maxAmp;
-        int verarbeitungsrate;
-        Verarbeitungsergebnis(String status, short maxAmp, int verarbeitungsrate) {
-            this.status = status;
-            this.maxAmp = maxAmp;
-            this.verarbeitungsrate = verarbeitungsrate;
-        }
-    }
-
-    class RingPuffer {
-        private short[] puffer;
-        private final int laenge;
-        private int anzahlEnthaltenerDaten;
-        private int position;
-
-        public RingPuffer(int n) {
-            laenge = n;
-            anzahlEnthaltenerDaten = 0;
-            position = 0;
-            puffer = new short[laenge];
-        }
-
-        public void hinzufuegen(short wert) {
-            puffer[position] = wert;
-            position++;
-            if (position >= laenge) {
-                position = 0;
-            }
-            if (anzahlEnthaltenerDaten < laenge) {
-                anzahlEnthaltenerDaten++;
-            }
-        }
-
-        public void hinzufuegen(short[] daten) {
-            for (short d : daten) {
-                puffer[position] = d;
-                position++;
-                if (position >= laenge) {
-                    position = 0;
-                }
-            }
-            if (anzahlEnthaltenerDaten < laenge) {
-                anzahlEnthaltenerDaten += daten.length;
-                if (anzahlEnthaltenerDaten >= laenge) {
-                    anzahlEnthaltenerDaten = laenge;
-                }
-            }
-        }
-
-        public short maximum() {
-            short max = 0;
-            for (int i = 0; i < anzahlEnthaltenerDaten; i++) {
-                if (puffer[i] > max) {
-                    max = puffer[i];
-                }
-            }
-            return max;
-        }
-
-        public float mittelwert() {
-            float summe = 0;
-            for (int i = 0; i < anzahlEnthaltenerDaten; i++) {
-                summe += puffer[i];
-            }
-            return summe / anzahlEnthaltenerDaten;
-        }
-    }
-
-    class GleitenderMittelwert {
-        private final float wichtungNeuerWert;
-        private final float wichtungAlterWert;
-        private float mittelwert = 0;
-        private boolean istMittelwertGesetzt = false;
-
-        GleitenderMittelwert(float wichtungNeuerWert) {
-            this.wichtungNeuerWert = wichtungNeuerWert;
-            this.wichtungAlterWert = 1 - this.wichtungNeuerWert;
-        }
-
-        float MittelwertPuffer(short[] puffer) {
-
-            for (int i = 0; i < puffer.length; i++) {
-                mittelwert = Math.abs(puffer[i]);
-            }
-            mittelwert = mittelwert/puffer.length;
-
-            return mittelwert;
-        }
-
-        float mittel(float wert) {
-            if (istMittelwertGesetzt) {
-                mittelwert = wert * wichtungNeuerWert + mittelwert * wichtungAlterWert;
-            } else {
-                mittelwert = wert;
-                istMittelwertGesetzt = true;
-            }
-            return mittelwert;
-        }
-    }
-}

app/src/main/java/com/example/ueberwachungssystem/Signalverarbeitung/Complex.java

@@ -1,148 +0,0 @@
-package com.example.ueberwachungssystem.Signalverarbeitung;
-
-import java.util.Objects;
-
-public class Complex {
-    private final double re;   // the real part
-    private final double im;   // the imaginary part
-
-    // create a new object with the given real and imaginary parts
-    public Complex(double real, double imag) {
-        re = real;
-        im = imag;
-    }
-
-    // return a string representation of the invoking com.example.ueberwachungssystem.Signalverarbeitung.Complex object
-    public String toString() {
-        if (im == 0) return re + "";
-        if (re == 0) return im + "i";
-        if (im < 0) return re + " - " + (-im) + "i";
-        return re + " + " + im + "i";
-    }
-
-    // return abs/modulus/magnitude
-    public double abs() {
-        return Math.hypot(re, im);
-    }
-
-    // return angle/phase/argument, normalized to be between -pi and pi
-    public double phase() {
-        return Math.atan2(im, re);
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is (this + b)
-    public Complex plus(Complex b) {
-        Complex a = this;             // invoking object
-        double real = a.re + b.re;
-        double imag = a.im + b.im;
-        return new Complex(real, imag);
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is (this - b)
-    public Complex minus(Complex b) {
-        Complex a = this;
-        double real = a.re - b.re;
-        double imag = a.im - b.im;
-        return new Complex(real, imag);
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is (this * b)
-    public Complex times(Complex b) {
-        Complex a = this;
-        double real = a.re * b.re - a.im * b.im;
-        double imag = a.re * b.im + a.im * b.re;
-        return new Complex(real, imag);
-    }
-
-    // return a new object whose value is (this * alpha)
-    public Complex scale(double alpha) {
-        return new Complex(alpha * re, alpha * im);
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is the conjugate of this
-    public Complex conjugate() {
-        return new Complex(re, -im);
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is the reciprocal of this
-    public Complex reciprocal() {
-        double scale = re * re + im * im;
-        return new Complex(re / scale, -im / scale);
-    }
-
-    // return the real or imaginary part
-    public double re() {
-        return re;
-    }
-
-    public double im() {
-        return im;
-    }
-
-    // return a / b
-    public Complex divides(Complex b) {
-        Complex a = this;
-        return a.times(b.reciprocal());
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is the complex exponential of this
-    public Complex exp() {
-        return new Complex(Math.exp(re) * Math.cos(im), Math.exp(re) * Math.sin(im));
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is the complex sine of this
-    public Complex sin() {
-        return new Complex(Math.sin(re) * Math.cosh(im), Math.cos(re) * Math.sinh(im));
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is the complex cosine of this
-    public Complex cos() {
-        return new Complex(Math.cos(re) * Math.cosh(im), -Math.sin(re) * Math.sinh(im));
-    }
-
-    // return a new com.example.ueberwachungssystem.Signalverarbeitung.Complex object whose value is the complex tangent of this
-    public Complex tan() {
-        return sin().divides(cos());
-    }
-
-    // a static version of plus
-    public static Complex plus(Complex a, Complex b) {
-        double real = a.re + b.re;
-        double imag = a.im + b.im;
-        Complex sum = new Complex(real, imag);
-        return sum;
-    }
-
-    // See Section 3.3.
-    public boolean equals(Object x) {
-        if (x == null) return false;
-        if (this.getClass() != x.getClass()) return false;
-        Complex that = (Complex) x;
-        return (this.re == that.re) && (this.im == that.im);
-    }
-
-    // See Section 3.3.
-    public int hashCode() {
-        return Objects.hash(re, im);
-    }
-
-    // sample client for testing
-    public static void main(String[] args) {
-        Complex a = new Complex(5.0, 6.0);
-        Complex b = new Complex(-3.0, 4.0);
-
-        System.out.println("a            = " + a);
-        System.out.println("b            = " + b);
-        System.out.println("Re(a)        = " + a.re());
-        System.out.println("Im(a)        = " + a.im());
-        System.out.println("b + a        = " + b.plus(a));
-        System.out.println("a - b        = " + a.minus(b));
-        System.out.println("a * b        = " + a.times(b));
-        System.out.println("b * a        = " + b.times(a));
-        System.out.println("a / b        = " + a.divides(b));
-        System.out.println("(a / b) * b  = " + a.divides(b).times(b));
-        System.out.println("conj(a)      = " + a.conjugate());
-        System.out.println("|a|          = " + a.abs());
-        System.out.println("tan(a)       = " + a.tan());
-    }
-}

app/src/main/java/com/example/ueberwachungssystem/Signalverarbeitung/FFT.java

@@ -1,248 +0,0 @@
-package com.example.ueberwachungssystem.Signalverarbeitung;
-// Source: https://introcs.cs.princeton.edu/java/97data/FFT.java.html
-
-import android.util.Log;
-
-/******************************************************************************
- *  Compilation:  javac FFT.java
- *  Execution:    java FFT n
- *  Dependencies: com.example.ueberwachungssystem.Signalverarbeitung.Complex.java
- *
- *  Compute the FFT and inverse FFT of a length n complex sequence
- *  using the radix 2 Cooley-Tukey algorithm.
- *  Bare bones implementation that runs in O(n log n) time and O(n)
- *  space. Our goal is to optimize the clarity of the code, rather
- *  than performance.
- *
- *  This implementation uses the primitive root of unity w = e^(-2 pi i / n).
- *  Some resources use w = e^(2 pi i / n).
- *
- *  Reference: https://www.cs.princeton.edu/~wayne/kleinberg-tardos/pdf/05DivideAndConquerII.pdf
- *
- *  Limitations
- *  -----------
- *   -  assumes n is a power of 2
- *
- *   -  not the most memory efficient algorithm (because it uses
- *      an object type for representing complex numbers and because
- *      it re-allocates memory for the subarray, instead of doing
- *      in-place or reusing a single temporary array)
- *
- *  For an in-place radix 2 Cooley-Tukey FFT, see
- *  https://introcs.cs.princeton.edu/java/97data/InplaceFFT.java.html
- *
- ******************************************************************************/
-
-public class FFT {
-
-    // compute the FFT of x[], assuming its length n is a power of 2
-    public static Complex[] fft(Complex[] x) {
-        int n = x.length;
-
-        // base case
-        if (n == 1) return new Complex[]{x[0]};
-
-        // radix 2 Cooley-Tukey FFT
-        if (n % 2 != 0) {
-            throw new IllegalArgumentException("n is not a power of 2");
-        }
-
-        // compute FFT of even terms
-        Complex[] even = new Complex[n / 2];
-        for (int k = 0; k < n / 2; k++) {
-            even[k] = x[2 * k];
-        }
-        Complex[] evenFFT = fft(even);
-
-        // compute FFT of odd terms
-        Complex[] odd = even;  // reuse the array (to avoid n log n space)
-        for (int k = 0; k < n / 2; k++) {
-            odd[k] = x[2 * k + 1];
-        }
-        Complex[] oddFFT = fft(odd);
-
-        // combine
-        Complex[] y = new Complex[n];
-        for (int k = 0; k < n / 2; k++) {
-            double kth = -2 * k * Math.PI / n;
-            Complex wk = new Complex(Math.cos(kth), Math.sin(kth));
-            y[k] = evenFFT[k].plus(wk.times(oddFFT[k]));
-            y[k + n / 2] = evenFFT[k].minus(wk.times(oddFFT[k]));
-        }
-        return y;
-    }
-
-
-    // compute the inverse FFT of x[], assuming its length n is a power of 2
-    public static Complex[] ifft(Complex[] x) {
-        int n = x.length;
-        Complex[] y = new Complex[n];
-
-        // take conjugate
-        for (int i = 0; i < n; i++) {
-            y[i] = x[i].conjugate();
-        }
-
-        // compute forward FFT
-        y = fft(y);
-
-        // take conjugate again
-        for (int i = 0; i < n; i++) {
-            y[i] = y[i].conjugate();
-        }
-
-        // divide by n
-        for (int i = 0; i < n; i++) {
-            y[i] = y[i].scale(1.0 / n);
-        }
-
-        return y;
-
-    }
-
-    // compute the circular convolution of x and y
-    public static Complex[] cconvolve(Complex[] x, Complex[] y) {
-
-        // should probably pad x and y with 0s so that they have same length
-        // and are powers of 2
-        if (x.length != y.length) {
-            throw new IllegalArgumentException("Dimensions don't agree");
-        }
-
-        int n = x.length;
-
-        // compute FFT of each sequence
-        Complex[] a = fft(x);
-        Complex[] b = fft(y);
-
-        // point-wise multiply
-        Complex[] c = new Complex[n];
-        for (int i = 0; i < n; i++) {
-            c[i] = a[i].times(b[i]);
-        }
-
-        // compute inverse FFT
-        return ifft(c);
-    }
-
-
-    // compute the linear convolution of x and y
-    public static Complex[] convolve(Complex[] x, Complex[] y) {
-        Complex ZERO = new Complex(0, 0);
-
-        Complex[] a = new Complex[2 * x.length];
-        for (int i = 0; i < x.length; i++) a[i] = x[i];
-        for (int i = x.length; i < 2 * x.length; i++) a[i] = ZERO;
-
-        Complex[] b = new Complex[2 * y.length];
-        for (int i = 0; i < y.length; i++) b[i] = y[i];
-        for (int i = y.length; i < 2 * y.length; i++) b[i] = ZERO;
-
-        return cconvolve(a, b);
-    }
-
-    // compute the DFT of x[] via brute force (n^2 time)
-    public static Complex[] dft(Complex[] x) {
-        int n = x.length;
-        Complex ZERO = new Complex(0, 0);
-        Complex[] y = new Complex[n];
-        for (int k = 0; k < n; k++) {
-            y[k] = ZERO;
-            for (int j = 0; j < n; j++) {
-                int power = (k * j) % n;
-                double kth = -2 * power * Math.PI / n;
-                Complex wkj = new Complex(Math.cos(kth), Math.sin(kth));
-                y[k] = y[k].plus(x[j].times(wkj));
-            }
-        }
-        return y;
-    }
-
-    // display an array of com.example.ueberwachungssystem.Signalverarbeitung.Complex numbers to standard output
-    public static void show(Complex[] x, String title) {
-        System.out.println(title);
-        System.out.println("-------------------");
-        for (int i = 0; i < x.length; i++) {
-            System.out.println(x[i]);
-        }
-        System.out.println();
-    }
-
-    /***************************************************************************
-     *  Test client and sample execution
-     *
-     *  % java FFT 4
-     *  x
-     *  -------------------
-     *  -0.03480425839330703
-     *  0.07910192950176387
-     *  0.7233322451735928
-     *  0.1659819820667019
-     *
-     *  y = fft(x)
-     *  -------------------
-     *  0.9336118983487516
-     *  -0.7581365035668999 + 0.08688005256493803i
-     *  0.44344407521182005
-     *  -0.7581365035668999 - 0.08688005256493803i
-     *
-     *  z = ifft(y)
-     *  -------------------
-     *  -0.03480425839330703
-     *  0.07910192950176387 + 2.6599344570851287E-18i
-     *  0.7233322451735928
-     *  0.1659819820667019 - 2.6599344570851287E-18i
-     *
-     *  c = cconvolve(x, x)
-     *  -------------------
-     *  0.5506798633981853
-     *  0.23461407150576394 - 4.033186818023279E-18i
-     *  -0.016542951108772352
-     *  0.10288019294318276 + 4.033186818023279E-18i
-     *
-     *  d = convolve(x, x)
-     *  -------------------
-     *  0.001211336402308083 - 3.122502256758253E-17i
-     *  -0.005506167987577068 - 5.058885073636224E-17i
-     *  -0.044092969479563274 + 2.1934338938072244E-18i
-     *  0.10288019294318276 - 3.6147323062478115E-17i
-     *  0.5494685269958772 + 3.122502256758253E-17i
-     *  0.240120239493341 + 4.655566391833896E-17i
-     *  0.02755001837079092 - 2.1934338938072244E-18i
-     *  4.01805098805014E-17i
-     *
-     ***************************************************************************/
-
-    public static void main(String[] args) {
-        int n = Integer.parseInt(args[0]);
-        Complex[] x = new Complex[n];
-
-        // original data
-        for (int i = 0; i < n; i++) {
-            x[i] = new Complex(i, 0);
-        }
-        show(x, "x");
-
-        // FFT of original data
-        Complex[] y = fft(x);
-        show(y, "y = fft(x)");
-
-        // FFT of original data
-        Complex[] y2 = dft(x);
-        show(y2, "y2 = dft(x)");
-
-        // take inverse FFT
-        Complex[] z = ifft(y);
-        show(z, "z = ifft(y)");
-
-        // circular convolution of x with itself
-        Complex[] c = cconvolve(x, x);
-        show(c, "c = cconvolve(x, x)");
-
-        // linear convolution of x with itself
-        Complex[] d = convolve(x, x);
-        show(d, "d = convolve(x, x)");
-    }
-}
-
-

app/src/main/java/com/example/ueberwachungssystem/logger/Logger.java

@@ -1,61 +0,0 @@
-package com.example.ueberwachungssystem.logger;
-
-import android.util.Log;
-import android.widget.TextView;
-
-import java.io.PrintWriter;
-import java.io.StringWriter;
-
-public class Logger {
-    private TextView textView; 
-    private StringBuffer sb = new StringBuffer(); 
-    private String tag;
-    private int lengthOfLastLog = 0;
-    private boolean overwrite = false;
-
-    public Logger(String tag, TextView textView, String logInitText)  {
-        this.tag = tag;
-        this.textView = textView;
-        sb.append(logInitText);
-    }
-
-    public void log(String s)  {
-        overwrite = false;
-        Log.d(tag, s);
-        sb.append(s).append("\n");
-        if (textView != null) {
-            textView.setText(sb.toString());
-        }
-    }
-
-    public void overwriteLastlog(String s)  {
-        Log.d(tag, s);
-        lengthOfLastLog = s.length();
-        if (overwrite)
-        {
-            sb.setLength(sb.length() - (lengthOfLastLog + 1));
-        }
-        sb.append(s).append("\n");
-        overwrite = true;
-        if (textView != null) {
-            textView.setText(sb.toString());
-        }
-    }
-
-    public void log(Exception e)  {
-        StringWriter sw = new StringWriter();
-        e.printStackTrace(new PrintWriter(sw));
-        log(sw.toString());
-    }
-
-    public void clearLog()  {
-        sb.setLength(0);
-        if (textView != null) {
-            textView.setText("");
-        }
-    }
-
-    public String getLoggedText()  {
-        return sb.toString();
-    }
-}

app/src/main/res/layout/activity_main.xml

@@ -5,52 +5,44 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:layout_gravity="center"
-    android:gravity="top"
+    android:gravity="center"
     android:orientation="vertical"
     tools:context=".MainActivity">
 
-
     <TextView
         android:id="@+id/textView"
-        android:layout_width="match_parent"
-        android:layout_height="100dp"
-        android:text="TextView" />
-
-    <androidx.camera.view.PreviewView
-        android:id="@+id/previewView"
-        android:layout_width="match_parent"
+        android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:backgroundTint="@android:color/black"/>
+        android:text=""
+        android:textSize="20dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
 
     <ToggleButton
-        android:id="@+id/toggleButton"
+        android:id="@+id/previewButton"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="ToggleButton" />
 
-    <ImageView
-        android:id="@+id/inputImageView"
+
+    <ToggleButton
+        android:id="@+id/toggleButton2"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        tools:srcCompat="@tools:sample/avatars" />
+        android:text="ToggleButton" />
 
-    <ImageView
-        android:id="@+id/outputImageView"
+    <androidx.camera.view.PreviewView
+        android:id="@+id/previewView"
         android:layout_width="match_parent"
-        android:layout_height="1dp"
-        tools:srcCompat="@tools:sample/avatars" />
+        android:layout_height="200dp" />
 
-    <com.jjoe64.graphview.GraphView
-        android:id="@+id/graph"
+    <VideoView
+        android:id="@+id/videoView"
         android:layout_width="match_parent"
-        android:layout_height="200dip"
-        android:layout_marginStart="16dp"
-        android:layout_marginEnd="16dp"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent"
-        app:layout_constraintVertical_bias="0.499" />
+        android:layout_height="wrap_content" />
 
 
 </LinearLayout>

gradle.properties

@@ -18,5 +18,4 @@ android.useAndroidX=true
 # Enables namespacing of each library's R class so that its R class includes only the
 # resources declared in the library itself and none from the library's dependencies,
 # thereby reducing the size of the R class for that library
-android.nonTransitiveRClass=true
-android.enableJetifier=true
+android.nonTransitiveRClass=true