Add webcam streamer

webcam-capture/src/main/java/com/github/sarxos/webcam/WebcamStreamer.java

@@ -0,0 +1,225 @@
+package com.github.sarxos.webcam;
+
+import java.awt.image.BufferedImage;
+import java.io.BufferedReader;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import javax.imageio.ImageIO;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+public class WebcamStreamer implements ThreadFactory, WebcamListener {
+
+	private static final Logger LOG = LoggerFactory.getLogger(WebcamStreamer.class);
+
+	private static final String BOUNDARY = "mjpeg-frame";
+
+	private class Acceptor implements Runnable {
+
+		@Override
+		public void run() {
+			try {
+				ServerSocket server = new ServerSocket(port);
+				while (true) {
+					executor.execute(new Connection(server.accept()));
+				}
+			} catch (Exception e) {
+				LOG.error("Cannot accept socket connection", e);
+			}
+		}
+	}
+
+	private class Reader implements Runnable {
+
+		@Override
+		public void run() {
+			while (webcam.isOpen()) {
+
+				image = webcam.getImage();
+
+				if (image != null) {
+					synchronized (lock) {
+						lock.notifyAll();
+					}
+				}
+
+				try {
+					Thread.sleep(getDelay());
+				} catch (InterruptedException e) {
+					LOG.error("Nasty interrupted exception", e);
+				}
+			}
+		}
+	}
+
+	private class Connection implements Runnable {
+
+		private Socket socket = null;
+
+		public Connection(Socket socket) {
+			this.socket = socket;
+		}
+
+		@Override
+		public void run() {
+
+			BufferedReader br = null;
+			DataOutputStream dos = null;
+
+			try {
+
+				br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+				dos = new DataOutputStream(socket.getOutputStream());
+
+				try {
+					while (true) {
+
+						String line = br.readLine();
+						if (line.isEmpty()) {
+							break;
+						}
+
+						if (line.startsWith("GET")) {
+
+							socket.setSoTimeout(0);
+							socket.setKeepAlive(true);
+
+							StringBuilder sb = new StringBuilder();
+							sb.append("HTTP/1.0 200 OK\n");
+							sb.append("Connection: keep-alive\n");
+							sb.append("Cache-Control: no-cache\n");
+							sb.append("Cache-Control: private\n");
+							sb.append("Pragma: no-cache\n");
+							sb.append("Content-type: multipart/x-mixed-replace; boundary=").append(BOUNDARY).append("\n\n");
+
+							dos.writeBytes(sb.toString());
+							dos.flush();
+
+							do {
+
+								sb.delete(0, sb.length());
+
+								sb.append("--").append(BOUNDARY).append("\n");
+								sb.append("Content-type: image/jpeg\n\n");
+
+								dos.writeBytes(sb.toString());
+
+								ImageIO.write(getImage(), "JPG", dos);
+
+								dos.flush();
+
+								Thread.sleep(getDelay());
+
+							} while (true);
+						}
+					}
+				} catch (Exception e) {
+					dos.writeBytes("HTTP/1.0 501 Internal Server Error\n\n\n");
+				}
+
+			} catch (IOException e) {
+				LOG.error("I/O exception", e);
+			} finally {
+				if (br != null) {
+					try {
+						br.close();
+					} catch (IOException e) {
+						LOG.error("Cannot close buffered reader", e);
+					}
+				}
+				if (dos != null) {
+					try {
+						dos.close();
+					} catch (IOException e) {
+						LOG.error("Cannot close data output stream", e);
+					}
+				}
+			}
+		}
+	}
+
+	private Webcam webcam = null;
+	private double fps = 0;
+	private BufferedImage image = null;
+	private Object lock = new Object();
+	private int number = 0;
+	private int port = 0;
+	private Executor executor = Executors.newCachedThreadPool(this);
+	private AtomicBoolean open = new AtomicBoolean(false);
+	private AtomicBoolean initialized = new AtomicBoolean(false);
+
+	public WebcamStreamer(int port, Webcam webcam, double fps, boolean start) {
+
+		if (webcam == null) {
+			throw new IllegalArgumentException("Webcam for streaming cannot be null");
+		}
+
+		this.port = port;
+		this.webcam = webcam;
+		this.fps = fps;
+
+		if (start) {
+			start();
+		}
+	}
+
+	private long getDelay() {
+		return (long) (1000 / fps);
+	}
+
+	private BufferedImage getImage() {
+		if (image == null) {
+			synchronized (lock) {
+				try {
+					lock.wait();
+				} catch (InterruptedException e) {
+					LOG.error("Nasty interrupted exception", e);
+				}
+			}
+		}
+		return image;
+	}
+
+	public void start() {
+		if (open.compareAndSet(false, true)) {
+			webcam.addWebcamListener(this);
+			webcam.open();
+		}
+	}
+
+	@Override
+	public Thread newThread(Runnable r) {
+		Thread thread = new Thread(r, String.format("streamer-thread-%s", number++));
+		thread.setDaemon(true);
+		return thread;
+	}
+
+	@Override
+	public void webcamOpen(WebcamEvent we) {
+		if (initialized.compareAndSet(false, true)) {
+			executor.execute(new Acceptor());
+			executor.execute(new Reader());
+		}
+	}
+
+	@Override
+	public void webcamClosed(WebcamEvent we) {
+	}
+
+	public static void main(String[] args) throws InterruptedException {
+		new WebcamStreamer(8081, Webcam.getDefault(), 0.5, true);
+		do {
+			Thread.sleep(1000);
+		} while (true);
+	}
+}