sarxos
commented
10 years ago Hi @kaustubhasgudi,
Do not modify the lock state unless you are completely aware of what you are doing. Especially on Windows. Locking has been designed to get rid of weird Microsoft issues with accessing DirectShow from two parallel contexts, which in some cases causes JVM to crash.
You do not also need to use webcam device because all the information you are getting from it are already available from webcam object.
Modified source code:
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import javax.imageio.ImageIO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.github.sarxos.webcam.Webcam;
import com.github.sarxos.webcam.WebcamException;
import com.github.sarxos.webcam.WebcamResolution;
public class X {
private static final Logger LOGGER = LoggerFactory.getLogger(X.class);
private static final String WEBCAMSHOTS_DIR = "./dir";
private static final String WEBCAMSHOT_FILE_NAME = "test.jpg";
public static void main(String[] args) {
new X().capture();
}
private void capture() {
int delay = 3; // 3 seconds, but you can set it to whatever you want
Dimension size = WebcamResolution.VGA.getSize();
Webcam defaultWebcam = Webcam.getDefault();
if (defaultWebcam == null) {
LOGGER.error("There is no webcam detected in the system");
return;
}
try {
defaultWebcam.setViewSize(size);
defaultWebcam.open();
captureWebcamImage(defaultWebcam, delay);
} catch (Exception e) {
e.printStackTrace();
} finally {
defaultWebcam.close();
}
}
private void captureWebcamImage(Webcam defaultWebcam, int delay) throws InterruptedException, WebcamException, IOException {
Dimension resolution = defaultWebcam.getViewSize();
Dimension[] resolutions = defaultWebcam.getViewSizes();
LOGGER.info(String.format("Webcam device: %s", defaultWebcam.getName()));
LOGGER.info(String.format("Webcam current resolution: %dx%d", resolution.width, resolution.height));
StringBuilder sb = new StringBuilder();
String delimiter = "";
for (Dimension r : resolutions) {
sb.append(delimiter).append(String.format("%dx%d", r.width, r.height));
delimiter = ", ";
}
LOGGER.info(String.format("Webcam supported resolutions: %s", sb.toString()));
if (delay > 0) {
LOGGER.info(String.format("Waiting %d seconds...", delay));
Thread.sleep(TimeUnit.MILLISECONDS.convert(delay, TimeUnit.SECONDS));
}
final BufferedImage img = defaultWebcam.getImage();
if (img == null) {
throw new WebcamException("The webcam is not available.");
}
LOGGER.info(String.format("Taking a %dx%d image...", img.getWidth(), img.getHeight()));
new File(WEBCAMSHOTS_DIR).mkdir();
final String imageName = WEBCAMSHOTS_DIR + File.separator + WEBCAMSHOT_FILE_NAME;
final File imageFile = new File(imageName);
if (!imageFile.exists()) {
LOGGER.debug(String.format("The image file does not exist, creating: %s", imageFile));
if (!imageFile.createNewFile()) {
throw new WebcamException("The image file cannot be created.");
}
}
ImageIO.write(img, "JPG", imageFile);
ClientState.getInstance().setWebcamImage(img);
}
public File getWebcamImageFile() {
return new File(WEBCAMSHOTS_DIR, WEBCAMSHOT_FILE_NAME);
}
}The exception you've observed is harmless and you can simply ignore it, but still I did small change in the source code which should get rid of it in the future.
Please donate to the project if you consider this information as useful.
kaustubhasgudi
Hello
I receive this exception from webcam-capture library :
Environment Details : Windows 7 Professional SP1 x64 JDK 1.7.0_45 x64 WebCam : Lenovo Think Advantage webcam for Lenovo Thinkpad T430
Libraries : bridj-0.7-20131007.003529-54.jar webcam-capture-0.3.10-RC6
Given below is the code for webcam capture :
Most of the time the webcam capture process works fine but less often it show the above exception and sometimes the application silently exits (JVM crash). Please assist.