reduce camera cpu usage through sleeping webcam capture threads to match 10fps

src/main/java/com/sparrowwallet/sparrow/control/WebcamScanDevice.java

@@ -0,0 +1,354 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.github.sarxos.webcam.*;
+import com.github.sarxos.webcam.ds.buildin.natives.Device;
+import com.github.sarxos.webcam.ds.buildin.natives.DeviceList;
+import com.github.sarxos.webcam.ds.buildin.natives.OpenIMAJGrabber;
+import org.bridj.Pointer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.awt.*;
+import java.awt.color.ColorSpace;
+import java.awt.image.*;
+import java.nio.ByteBuffer;
+import java.util.Hashtable;
+import java.util.Iterator;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+@SuppressWarnings("deprecation")
+public class WebcamScanDevice implements WebcamDevice, WebcamDevice.BufferAccess, Runnable, WebcamDevice.FPSSource {
+    private static final Logger LOG = LoggerFactory.getLogger(WebcamScanDevice.class);
+    private static final int DEVICE_BUFFER_SIZE = 5;
+    private static final Dimension[] DIMENSIONS;
+    private static final int[] BAND_OFFSETS;
+    private static final int[] BITS;
+    private static final int[] OFFSET;
+    private static final int DATA_TYPE = 0;
+    private static final ColorSpace COLOR_SPACE;
+    public static final int SCAN_LOOP_WAIT_MILLIS = 100;
+    private int timeout = 5000;
+    private OpenIMAJGrabber grabber = null;
+    private Device device = null;
+    private Dimension size = null;
+    private ComponentSampleModel smodel = null;
+    private ColorModel cmodel = null;
+    private boolean failOnSizeMismatch = false;
+    private final AtomicBoolean disposed = new AtomicBoolean(false);
+    private final AtomicBoolean open = new AtomicBoolean(false);
+    private final AtomicBoolean fresh = new AtomicBoolean(false);
+    private Thread refresher = null;
+    private String name = null;
+    private String id = null;
+    private String fullname = null;
+    private long t1 = -1L;
+    private long t2 = -1L;
+    private volatile double fps = 0.0D;
+
+    protected WebcamScanDevice(Device device) {
+        this.device = device;
+        this.name = device.getNameStr();
+        this.id = device.getIdentifierStr();
+        this.fullname = String.format("%s %s", this.name, this.id);
+    }
+
+    public String getName() {
+        return this.fullname;
+    }
+
+    public String getDeviceName() {
+        return this.name;
+    }
+
+    public String getDeviceId() {
+        return this.id;
+    }
+
+    public Device getDeviceRef() {
+        return this.device;
+    }
+
+    public Dimension[] getResolutions() {
+        return DIMENSIONS;
+    }
+
+    public Dimension getResolution() {
+        if (this.size == null) {
+            this.size = this.getResolutions()[0];
+        }
+
+        return this.size;
+    }
+
+    public void setResolution(Dimension size) {
+        if (size == null) {
+            throw new IllegalArgumentException("Size cannot be null");
+        } else if (this.open.get()) {
+            throw new IllegalStateException("Cannot change resolution when webcam is open, please close it first");
+        } else {
+            this.size = size;
+        }
+    }
+
+    public ByteBuffer getImageBytes() {
+        if (this.disposed.get()) {
+            LOG.debug("Webcam is disposed, image will be null");
+            return null;
+        } else if (!this.open.get()) {
+            LOG.debug("Webcam is closed, image will be null");
+            return null;
+        } else {
+            if (this.fresh.compareAndSet(false, true)) {
+                this.updateFrameBuffer();
+            }
+
+            LOG.trace("Webcam grabber get image pointer");
+            Pointer<Byte> image = this.grabber.getImage();
+            this.fresh.set(false);
+            if (image == null) {
+                LOG.warn("Null array pointer found instead of image");
+                return null;
+            } else {
+                int length = this.size.width * this.size.height * 3;
+                LOG.trace("Webcam device get buffer, read {} bytes", length);
+                return image.getByteBuffer((long)length);
+            }
+        }
+    }
+
+    public void getImageBytes(ByteBuffer target) {
+        if (this.disposed.get()) {
+            LOG.debug("Webcam is disposed, image will be null");
+        } else if (!this.open.get()) {
+            LOG.debug("Webcam is closed, image will be null");
+        } else {
+            int minSize = this.size.width * this.size.height * 3;
+            int curSize = target.remaining();
+            if (minSize > curSize) {
+                throw new IllegalArgumentException(String.format("Not enough remaining space in target buffer (%d necessary vs %d remaining)", minSize, curSize));
+            } else {
+                if (this.fresh.compareAndSet(false, true)) {
+                    this.updateFrameBuffer();
+                }
+
+                LOG.trace("Webcam grabber get image pointer");
+                Pointer<Byte> image = this.grabber.getImage();
+                this.fresh.set(false);
+                if (image == null) {
+                    LOG.warn("Null array pointer found instead of image");
+                } else {
+                    LOG.trace("Webcam device read buffer {} bytes", minSize);
+                    image = image.validBytes((long)minSize);
+                    image.getBytes(target);
+                }
+            }
+        }
+    }
+
+    public BufferedImage getImage() {
+        ByteBuffer buffer = this.getImageBytes();
+        if (buffer == null) {
+            LOG.error("Images bytes buffer is null!");
+            return null;
+        } else {
+            byte[] bytes = new byte[this.size.width * this.size.height * 3];
+            byte[][] data = new byte[][]{bytes};
+            buffer.get(bytes);
+            DataBufferByte dbuf = new DataBufferByte(data, bytes.length, OFFSET);
+            WritableRaster raster = Raster.createWritableRaster(this.smodel, dbuf, (Point)null);
+            BufferedImage bi = new BufferedImage(this.cmodel, raster, false, (Hashtable)null);
+            bi.flush();
+            return bi;
+        }
+    }
+
+    public void open() {
+        if (!this.disposed.get()) {
+            LOG.debug("Opening webcam device {}", this.getName());
+            if (this.size == null) {
+                this.size = this.getResolutions()[0];
+            }
+
+            if (this.size == null) {
+                throw new RuntimeException("The resolution size cannot be null");
+            } else {
+                LOG.debug("Webcam device {} starting session, size {}", this.device.getIdentifierStr(), this.size);
+                this.grabber = new OpenIMAJGrabber();
+                DeviceList list = (DeviceList)this.grabber.getVideoDevices().get();
+                Iterator var2 = list.asArrayList().iterator();
+
+                while(var2.hasNext()) {
+                    Device d = (Device)var2.next();
+                    d.getNameStr();
+                    d.getIdentifierStr();
+                }
+
+                boolean started = this.grabber.startSession(this.size.width, this.size.height, 50, Pointer.pointerTo(this.device));
+                if (!started) {
+                    throw new WebcamException("Cannot start native grabber!");
+                } else {
+                    this.grabber.setTimeout(this.timeout);
+                    LOG.debug("Webcam device session started");
+                    Dimension size2 = new Dimension(this.grabber.getWidth(), this.grabber.getHeight());
+                    int w1 = this.size.width;
+                    int w2 = size2.width;
+                    int h1 = this.size.height;
+                    int h2 = size2.height;
+                    if (w1 != w2 || h1 != h2) {
+                        if (this.failOnSizeMismatch) {
+                            throw new WebcamException(String.format("Different size obtained vs requested - [%dx%d] vs [%dx%d]", w1, h1, w2, h2));
+                        }
+
+                        Object[] args = new Object[]{w1, h1, w2, h2, w2, h2};
+                        LOG.warn("Different size obtained vs requested - [{}x{}] vs [{}x{}]. Setting correct one. New size is [{}x{}]", args);
+                        this.size = new Dimension(w2, h2);
+                    }
+
+                    this.smodel = new ComponentSampleModel(0, this.size.width, this.size.height, 3, this.size.width * 3, BAND_OFFSETS);
+                    this.cmodel = new ComponentColorModel(COLOR_SPACE, BITS, false, false, 1, 0);
+                    LOG.debug("Clear memory buffer");
+                    this.clearMemoryBuffer();
+                    LOG.debug("Webcam device {} is now open", this);
+                    this.open.set(true);
+                    this.refresher = this.startFramesRefresher();
+                }
+            }
+        }
+    }
+
+    private void clearMemoryBuffer() {
+        for(int i = 0; i < 5; ++i) {
+            this.grabber.nextFrame();
+        }
+
+    }
+
+    private Thread startFramesRefresher() {
+        Thread refresher = new Thread(this, String.format("frames-refresher-[%s]", this.id));
+        refresher.setUncaughtExceptionHandler(WebcamExceptionHandler.getInstance());
+        refresher.setDaemon(true);
+        refresher.start();
+        return refresher;
+    }
+
+    public void close() {
+        if (this.open.compareAndSet(true, false)) {
+            LOG.debug("Closing webcam device");
+            this.grabber.stopSession();
+        }
+    }
+
+    public void dispose() {
+        if (this.disposed.compareAndSet(false, true)) {
+            LOG.debug("Disposing webcam device {}", this.getName());
+            this.close();
+        }
+    }
+
+    public void setFailOnSizeMismatch(boolean fail) {
+        this.failOnSizeMismatch = fail;
+    }
+
+    public boolean isOpen() {
+        return this.open.get();
+    }
+
+    public int getTimeout() {
+        return this.timeout;
+    }
+
+    public void setTimeout(int timeout) {
+        if (this.isOpen()) {
+            throw new WebcamException("Timeout must be set before webcam is open");
+        } else {
+            this.timeout = timeout;
+        }
+    }
+
+    private void updateFrameBuffer() {
+        LOG.trace("Next frame");
+        if (this.t1 == -1L || this.t2 == -1L) {
+            this.t1 = System.currentTimeMillis();
+            this.t2 = System.currentTimeMillis();
+        }
+
+        int result = (new WebcamScanDevice.NextFrameTask(this)).nextFrame();
+        this.t1 = this.t2;
+        this.t2 = System.currentTimeMillis();
+        this.fps = (4.0D * this.fps + (double)(1000L / (this.t2 - this.t1 + 1L))) / 5.0D;
+        if (result == -1) {
+            LOG.error("Timeout when requesting image!");
+        } else if (result < -1) {
+            LOG.error("Error requesting new frame!");
+        }
+
+    }
+
+    public void run() {
+        do {
+            try {
+                Thread.sleep(SCAN_LOOP_WAIT_MILLIS);
+            } catch(InterruptedException e) {
+                //ignore
+            }
+
+            if (Thread.interrupted()) {
+                LOG.debug("Refresher has been interrupted");
+                return;
+            }
+
+            if (!this.open.get()) {
+                LOG.debug("Cancelling refresher");
+                return;
+            }
+
+            this.updateFrameBuffer();
+        } while(this.open.get());
+
+    }
+
+    public double getFPS() {
+        return this.fps;
+    }
+
+    static {
+        DIMENSIONS = new Dimension[]{WebcamResolution.QQVGA.getSize(), WebcamResolution.QVGA.getSize(), WebcamResolution.VGA.getSize()};
+        BAND_OFFSETS = new int[]{0, 1, 2};
+        BITS = new int[]{8, 8, 8};
+        OFFSET = new int[]{0};
+        COLOR_SPACE = ColorSpace.getInstance(1000);
+    }
+
+    private class NextFrameTask extends WebcamTask {
+        private final AtomicInteger result = new AtomicInteger(0);
+
+        public NextFrameTask(WebcamDevice device) {
+            super(device);
+        }
+
+        public int nextFrame() {
+            try {
+                this.process();
+            } catch (InterruptedException var2) {
+                WebcamScanDevice.LOG.debug("Image buffer request interrupted", var2);
+            }
+
+            return this.result.get();
+        }
+
+        protected void handle() {
+            WebcamScanDevice device = (WebcamScanDevice)this.getDevice();
+            if (device.isOpen()) {
+                try {
+                    Thread.sleep(SCAN_LOOP_WAIT_MILLIS);
+                } catch(InterruptedException e) {
+                    //ignore
+                }
+
+                this.result.set(WebcamScanDevice.this.grabber.nextFrame());
+                WebcamScanDevice.this.fresh.set(true);
+            }
+        }
+    }
+}

src/main/java/com/sparrowwallet/sparrow/control/WebcamScanDriver.java

@@ -0,0 +1,22 @@
+package com.sparrowwallet.sparrow.control;
+
+import com.github.sarxos.webcam.WebcamDevice;
+import com.github.sarxos.webcam.ds.buildin.WebcamDefaultDevice;
+import com.github.sarxos.webcam.ds.buildin.WebcamDefaultDriver;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class WebcamScanDriver extends WebcamDefaultDriver {
+    @Override
+    public List<WebcamDevice> getDevices() {
+        List<WebcamDevice> devices = super.getDevices();
+        List<WebcamDevice> scanDevices = new ArrayList<>();
+        for(WebcamDevice device : devices) {
+            WebcamDefaultDevice defaultDevice = (WebcamDefaultDevice)device;
+            scanDevices.add(new WebcamScanDevice(defaultDevice.getDeviceRef()));
+        }
+
+        return scanDevices;
+    }
+}

src/main/java/com/sparrowwallet/sparrow/control/WebcamService.java

@@ -34,6 +34,10 @@ public class WebcamService extends ScheduledService<Image> {
     private Webcam cam;
     private long lastQrSampleTime;
 
+    static {
+        Webcam.setDriver(new WebcamScanDriver());
+    }
+
     public WebcamService(WebcamResolution resolution, WebcamListener listener, WebcamUpdater.DelayCalculator delayCalculator) {
         this.resolution = resolution;
         this.listener = listener;

src/main/java/module-info.java

@@ -29,4 +29,5 @@ open module com.sparrowwallet.sparrow {
     requires jtorctl;
     requires javacsv;
     requires jul.to.slf4j;
+    requires bridj;
 }

src/main/resources/com/sparrowwallet/sparrow/app.fxml

@@ -85,7 +85,7 @@
                         <SeparatorMenuItem />
                         <CheckMenuItem fx:id="openWalletsInNewWindows" mnemonicParsing="false" text="Open Wallets in New Windows" onAction="#openWalletsInNewWindows"/>
                         <CheckMenuItem fx:id="hideEmptyUsedAddresses" mnemonicParsing="false" text="Hide Empty Used Addresses" onAction="#hideEmptyUsedAddresses"/>
-                        <CheckMenuItem fx:id="useHdCameraResolution" mnemonicParsing="false" text="Use HD camera resolution" onAction="#useHdCameraResolution"/>
+                        <CheckMenuItem fx:id="useHdCameraResolution" mnemonicParsing="false" text="Use HD Camera Resolution" onAction="#useHdCameraResolution"/>
                         <CheckMenuItem fx:id="showTxHex" mnemonicParsing="false" text="Show Transaction Hex" onAction="#showTxHex"/>
                         <SeparatorMenuItem />
                         <MenuItem fx:id="minimizeToTray" mnemonicParsing="false" text="Minimize to System Tray" accelerator="Shortcut+Y" onAction="#minimizeToTray"/>