Question

在运行程序从网络摄像头捕获视频中抓取帧时，我遇到了NullPointerException问题。我试图更改捕获设备的设置但是没有像

这样的选项

“vfw：Microsoft WDM图像捕获（Win32）：0” 无法在jmf中找到设备。 .so直接提到参考资料的代码。但是没有工作！我正在使用net bean，jmf的库也包含在netbeans中。请帮我解决这个问题。我的代码：

package VideoSource;

/**
 *
 * @author sri 
 */
import java.awt.Frame; 
import javax.imageio.ImageIO;
import java.awt.Image; 
import java.awt.image.BufferedImage; 
import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;
import javax.media.Buffer; 
import javax.media.Manager; 
import javax.media.NoPlayerException;
import javax.media.Player; 
import javax.media.CaptureDeviceInfo;
import javax.media.control.FrameGrabbingControl; 
import javax.media.format.VideoFormat; 
import javax.media.util.BufferToImage; 
import javax.media.*;

public class frames {
     public static final String DEVICE ="vfw:Microsoft WDM Image Capture (Win32):0";

   //protected Player player;
    public static void main(String args[]) throws IOException, CannotRealizeException{
   try{ 

       CaptureDeviceInfo cdi = CaptureDeviceManager.getDevice(DEVICE);

    Player player = Manager.createRealizedPlayer(cdi.getLocator());
    player.start();
    FrameGrabbingControl frameGrabber = (FrameGrabbingControl) player.getControl("javax.media.control.FrameGrabbingControl");

   Buffer buf = frameGrabber.grabFrame();
   //BufferedImage buf1 = frameGrabber.grabFrame();
   // Convert frame to an buffered image so it can be processed and saved
Image img = (new BufferToImage((VideoFormat) buf.getFormat()).createImage(buf));
if(img!=null){
RenderedImage img1=(RenderedImage) img;
int i=0;
      File outputfile = new File("d:/Project/frame"+(i++)+".jpg");
      ImageIO.write(img1, "jpg", outputfile);
}
else
    System.out.println("null from frame grabbing");
//return img;
   }
   catch(NoPlayerException n)
   {

   }




}
}

我有例外：

Exception in thread "main" java.lang.NullPointerException
    at VideoSource.frames.main(frames.java:37)
Java Result: 1

视频码抛出异常的帧提取

0 个答案: