diff options
Diffstat (limited to 'smartdashboard/src/edu')
2 files changed, 215 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 f7662df..ce680a6 100644 --- a/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/DefaultDisplayElementRegistrar.java +++ b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/DefaultDisplayElementRegistrar.java @@ -30,6 +30,7 @@ public class DefaultDisplayElementRegistrar { DisplayElementRegistry.registerStaticWidget(Label.class); DisplayElementRegistry.registerStaticWidget(RobotPreferences.class); DisplayElementRegistry.registerStaticWidget(VideoStreamViewerExtension.class); + DisplayElementRegistry.registerStaticWidget(WebcamViewerExtension.class); } } diff --git a/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/WebcamViewerExtension.java b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/WebcamViewerExtension.java new file mode 100644 index 0000000..4230055 --- /dev/null +++ b/smartdashboard/src/edu/wpi/first/smartdashboard/gui/elements/WebcamViewerExtension.java @@ -0,0 +1,214 @@ +package edu.wpi.first.smartdashboard.gui.elements; + +import edu.wpi.first.smartdashboard.gui.StaticWidget; +import edu.wpi.first.smartdashboard.properties.*; +import edu.wpi.first.smartdashboard.robot.Robot; + +import javax.imageio.ImageIO; +import java.awt.*; +import java.awt.Graphics2D; +import java.awt.geom.AffineTransform; +import java.awt.image.BufferedImage; +import java.io.ByteArrayInputStream; +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.io.EOFException; +import java.net.Socket; +import java.net.ConnectException; +import java.util.Arrays; + +/** + * SmartDashboard extension for viewing a MJPEG stream from the robot, + * typically forwarded from a USB webcam, or images processed by a user + * program. This is mostly compatible with the LabVIEW dashboard in + * "HW Compression" mode. + * + * @author Tom Clark + */ +public class WebcamViewerExtension extends StaticWidget implements Runnable { + + public static final String NAME = "USB Webcam Viewer"; + + public final IntegerProperty fpsProperty = new IntegerProperty(this, "FPS", 30); + + private final static int PORT = 1180; + private final static byte[] MAGIC_NUMBERS = { 0x01, 0x00, 0x00, 0x00 }; + private final static int SIZE_640x480 = 0; + private final static int SIZE_320x240 = 1; + private final static int SIZE_160x120 = 2; + private final static int HW_COMPRESSION = -1; + + private BufferedImage frame = null; + private final Object frameMutex = new Object();; + private String errorMessage = null; + + private Socket socket; + private Thread thread; + + + /** {@inheritDoc} */ + @Override + public void init() { + setPreferredSize(new Dimension(320, 240)); + + this.thread = new Thread(this); + this.thread.start(); + + ImageIO.setUseCache(false); + } + + + /** {@inheritDoc} */ + @Override + public void disconnect() { + this.thread.stop(); + + if (this.socket != null) { + try { + this.socket.close(); + } + catch (IOException e) {} + } + } + + + /** {@inheritDoc} */ + @Override + public void propertyChanged(Property property) { + /* Close and reopen the stream with the new settings */ + this.thread.interrupt(); + } + + + /** + * Continuously request and receive frames from the roboRIO + */ + @Override + public void run() { + for (;;) { + try { + this.socket = new Socket(Robot.getHost(), PORT); + DataInputStream inputStream = new DataInputStream(this.socket.getInputStream()); + DataOutputStream outputStream = new DataOutputStream(this.socket.getOutputStream()); + + /* Send the request */ + outputStream.writeInt(this.fpsProperty.getValue()); + outputStream.writeInt(HW_COMPRESSION); + outputStream.writeInt(SIZE_640x480); + outputStream.flush(); + + /* Get the response from the robot */ + while (!Thread.interrupted()) { + /* Each frame has a header with 4 magic bytes and the number of bytes in the image */ + byte[] magic = new byte[4]; + inputStream.readFully(magic); + int size = inputStream.readInt(); + + assert Arrays.equals(magic, MAGIC_NUMBERS); + + + /* Get the image data itself, and make sure that it's a valid JPEG image (it starts with + * [0xff,0xd8] and ends with [0xff,0xd9] */ + byte[] data = new byte[size]; + inputStream.readFully(data); + + assert data.length >= 4 && data[0] == 0xff && data[1] == 0xd8 + && data[data.length - 2] == 0xff && data[data.length - 1] == 0xd9; + + + /* Decode the data and re-paint the component with the new frame */ + synchronized (this.frameMutex) { + if (this.frame != null) { + this.frame.flush(); + } + + this.frame = ImageIO.read(new ByteArrayInputStream(data)); + this.errorMessage = null; + this.repaint(); + } + } + } + catch (ConnectException e) { + if (this.errorMessage == null) { + this.errorMessage = e.getMessage(); + } + } + catch (EOFException e) { + if (this.errorMessage == null) { + this.errorMessage = "Robot stopped returning images"; + } + } + catch (IOException e) { + if (this.errorMessage == null) { + this.errorMessage = e.getMessage(); + } + } + finally { + if (this.socket != null) { + try { + this.socket.close(); + } + catch (IOException e) {} + } + + this.repaint(); + + try { + Thread.sleep(1000); + } + catch (InterruptedException e1) {} + } + } + } + + + /** + * Draw the latest image to the screen, blocking if one is being received, + * or showing an error message if there's some problem with the image. + * + * @param g the <code>Graphics</code> context in which to paint + */ + @Override + protected void paintComponent(Graphics g) { + int imageX = 0, + imageY = 0, + imageWidth = this.getWidth(), + imageHeight = this.getHeight(); + + synchronized (this.frameMutex) { + /* Adjust the image size and location depending on how the aspect ratio matches up with the aspect ratio + * of this component. */ + if (this.frame != null) { + float thisAspectRatio = (float) this.getWidth() / this.getHeight(); + float imageAspectRatio = (float) this.frame.getWidth(null) / this.frame.getHeight(null); + + if (imageAspectRatio < thisAspectRatio) { + imageWidth = (int) (this.getHeight() * imageAspectRatio); + imageX = (this.getWidth() - imageWidth) / 2; + } else { + imageHeight = (int) (this.getWidth() / imageAspectRatio); + imageY = (this.getHeight() - imageHeight) / 2; + } + + g.drawImage(this.frame, imageX, imageY, imageWidth, imageHeight, null, null); + } + + /* If there's some problem getting the image, show the error on the screen */ + if (this.errorMessage != null) { + g.setClip(imageX, imageY, imageWidth, imageHeight); + + g.setColor(Color.pink); + g.fillRect(imageX, imageY + imageHeight - 18, imageWidth, 18); + g.setColor(Color.black); + + Font font = g.getFont(); + + g.setFont(font.deriveFont(Font.BOLD)); + g.drawString("Error: ", imageX + 2, imageY + imageHeight - 6); + g.setFont(font); + g.drawString(this.errorMessage, imageX + 40, imageY + imageHeight - 6); + } + } + } +} |