Add a generalized VideoURLViewer widget

2 files changed, 217 insertions, 0 deletions

diff --git a/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/DefaultDisplayElementRegistrar.java b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/DefaultDisplayElementRegistrar.java
index e5854d5..db42035 100644
--- a/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/DefaultDisplayElementRegistrar.java
+++ b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/DefaultDisplayElementRegistrar.java
@@ -29,8 +29,10 @@ public class DefaultDisplayElementRegistrar {
         DisplayElementRegistry.registerStaticWidget(ConnectionIndicator.class);
         DisplayElementRegistry.registerStaticWidget(Label.class);
         DisplayElementRegistry.registerStaticWidget(RobotPreferences.class);
+
         DisplayElementRegistry.registerStaticWidget(RobotCameraViewer.class);
         DisplayElementRegistry.registerStaticWidget(AxisCameraViewer.class);
+        DisplayElementRegistry.registerStaticWidget(VideoURLViewer.class);
     }
 
 }
diff --git a/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/VideoURLViewer.java b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/VideoURLViewer.java
new file mode 100644
index 0000000..04c79c1
--- /dev/null
+++ b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/VideoURLViewer.java
@@ -0,0 +1,215 @@
+package edu.wpi.first.smartdashboard.gui.elements;
+
+import edu.wpi.first.smartdashboard.gui.DashboardPrefs;
+import edu.wpi.first.smartdashboard.gui.StaticWidget;
+import edu.wpi.first.smartdashboard.properties.IntegerProperty;
+import edu.wpi.first.smartdashboard.properties.Property;
+import edu.wpi.first.smartdashboard.properties.StringProperty;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.geom.AffineTransform;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLConnection;
+
+import javax.imageio.ImageIO;
+
+/**
+ * SmartDashboard widget for vieweing an abitrary video URL.  It can
+ * deal with the types supported by javax.imageio.ImageIO.
+ *
+ * To use with an Axis webcam, use http://HOSTNAME/mjpg/video.mjpg.
+ *
+ * @author Greg Granito
+ */
+public class VideoURLViewer extends StaticWidget {
+
+    public static final String NAME = "Video URL Viewer";
+
+
+    private static final int[] START_BYTES = new int[]{0xFF, 0xD8};
+    private static final int[] END_BYTES = new int[]{0xFF, 0xD9};
+
+    private boolean urlChanged = true;
+    private String urlString = null;
+    private double rotateAngleRad = 0;
+    private long lastFPSCheck = 0;
+    private int lastFPS = 0;
+    private int fpsCounter = 0;
+    public class BGThread extends Thread {
+
+        boolean destroyed = false;
+
+        public BGThread() {
+            super(NAME+" Background");
+        }
+
+        long lastRepaint = 0;
+        @Override
+        public void run() {
+            URLConnection connection = null;
+            InputStream stream = null;
+            ByteArrayOutputStream imageBuffer = new ByteArrayOutputStream();
+            while (!destroyed) {
+                try{
+                    System.out.println("Connecting to camera");
+                    urlChanged = false;
+                    URL url = new URL(urlString);
+                    connection = url.openConnection();
+                    connection.setReadTimeout(250);
+                    stream = connection.getInputStream();
+
+                    while(!destroyed && !urlChanged){
+                        while(System.currentTimeMillis()-lastRepaint<10){
+                            stream.skip(stream.available());
+                            Thread.sleep(1);
+                        }
+                        stream.skip(stream.available());
+
+                        imageBuffer.reset();
+                        for(int i = 0; i<START_BYTES.length;){
+                            int b = stream.read();
+                            if(b==START_BYTES[i])
+                                i++;
+                            else
+                                i = 0;
+                        }
+                        for(int i = 0; i<START_BYTES.length;++i)
+                            imageBuffer.write(START_BYTES[i]);
+
+                        for(int i = 0; i<END_BYTES.length;){
+                            int b = stream.read();
+                            imageBuffer.write(b);
+                            if(b==END_BYTES[i])
+                                i++;
+                            else
+                                i = 0;
+                        }
+
+                        fpsCounter++;
+                        if(System.currentTimeMillis()-lastFPSCheck>500){
+                            lastFPSCheck = System.currentTimeMillis();
+                            lastFPS = fpsCounter*2;
+                            fpsCounter = 0;
+                        }
+
+                        lastRepaint = System.currentTimeMillis();
+                        ByteArrayInputStream tmpStream = new ByteArrayInputStream(imageBuffer.toByteArray());
+                        imageToDraw = ImageIO.read(tmpStream);
+                        System.out.println(System.currentTimeMillis()-lastRepaint);
+                        repaint();
+                    }
+
+                } catch(Exception e){
+                    imageToDraw = null;
+                    repaint();
+                    e.printStackTrace();
+                }
+
+                if(!urlChanged){
+                    try {
+                        Thread.sleep(500);
+                    } catch (InterruptedException ex) {}
+                }
+            }
+
+        }
+
+        @Override
+        public void destroy() {
+            destroyed = true;
+        }
+    }
+    private BufferedImage imageToDraw;
+    private BGThread bgThread = new BGThread();
+    public final StringProperty urlProperty = new StringProperty(this, "Video URL", "http://axis-camera.local/mjpg/video.mjpg");
+    public final IntegerProperty rotateProperty = new IntegerProperty(this, "Degrees Rotation", 0);
+    
+    @Override
+    public void init() {
+        setPreferredSize(new Dimension(100, 100));
+        urlString = urlProperty.getSaveValue();
+        rotateAngleRad = Math.toRadians(rotateProperty.getValue());
+        bgThread.start();
+        revalidate();
+        repaint();
+    }
+
+    @Override
+    public void propertyChanged(Property property) {
+        if (property == urlProperty) {
+            urlString = urlProperty.getSaveValue();
+            urlChanged = true;
+        }
+        if (property == rotateProperty) {
+            rotateAngleRad = Math.toRadians(rotateProperty.getValue());
+        }
+
+    }
+
+    @Override
+    public void disconnect() {
+        bgThread.destroy();
+        super.disconnect();
+    }
+
+    @Override
+    protected void paintComponent(Graphics g) {
+        BufferedImage drawnImage = imageToDraw; 
+        
+        if (drawnImage != null) {
+        	// cast the Graphics context into a Graphics2D
+            Graphics2D g2d = (Graphics2D)g;
+            
+            // get the existing Graphics transform and copy it so that we can perform scaling and rotation
+            AffineTransform origXform = g2d.getTransform();
+            AffineTransform newXform = (AffineTransform)(origXform.clone());
+            
+            // find the center of the original image
+            int origImageWidth = drawnImage.getWidth();
+            int origImageHeight = drawnImage.getHeight();
+            int imageCenterX = origImageWidth/2;
+            int imageCenterY = origImageHeight/2;
+            
+            // perform the desired scaling
+            double panelWidth = getBounds().width;
+            double panelHeight = getBounds().height;
+            double panelCenterX = panelWidth/2.0;
+            double panelCenterY = panelHeight/2.0;
+            double rotatedImageWidth = origImageWidth * Math.abs(Math.cos(rotateAngleRad)) + origImageHeight * Math.abs(Math.sin(rotateAngleRad));
+            double rotatedImageHeight = origImageWidth * Math.abs(Math.sin(rotateAngleRad)) + origImageHeight * Math.abs(Math.cos(rotateAngleRad));         
+            		
+            // compute scaling needed
+            double scale = Math.min(panelWidth / rotatedImageWidth, panelHeight / rotatedImageHeight);
+                      
+            // set the transform before drawing the image
+            // 1 - translate the origin to the center of the panel
+            // 2 - perform the desired rotation (rotation will be about origin)
+            // 3 - perform the desired scaling (will scale centered about origin)
+            newXform.translate(panelCenterX,  panelCenterY);
+            newXform.rotate(rotateAngleRad);
+            newXform.scale(scale, scale);
+            g2d.setTransform(newXform);
+
+            // draw image so that the center of the image is at the "origin"; the transform will take care of the rotation and scaling
+            g2d.drawImage(drawnImage, -imageCenterX, -imageCenterY, null);
+            
+            // restore the original transform
+            g2d.setTransform(origXform);
+            
+            g.setColor(Color.PINK);
+            g.drawString("FPS: "+lastFPS, 10, 10);
+        } else {
+            g.setColor(Color.PINK);
+            g.fillRect(0, 0, getBounds().width, getBounds().height);
+            g.setColor(Color.BLACK);
+            g.drawString("NO CONNECTION", 10, 10);
+        }
+    }
+}