問題在Windows7的Java編程（在Windows XP中運行良好）

Question

我捕捉從連接到PC.I網絡攝像頭視頻我用下面的代碼可以這樣做：

import java.util.*; 
import javax.media.*; 
import javax.media.protocol.*; 
import javax.media.control.*; 
import javax.media.format.*; 
import java.awt.*; 
/** 
* This is the primary class to run. It gathers an image stream and drives the processing. 
* 
*/ 
public class jmfcam05v 
{ 
    DataSource dataSource; 
    PushBufferStream pbs; 

    Vector camImgSize = new Vector(); 
    Vector camCapDevice = new Vector(); 
    Vector camCapFormat = new Vector(); 

    int camFPS; 
    int camImgSel; 

    Processor processor = null; 
    DataSink datasink = null; 

    /** 
    * Main method to instance and run class 
    * 
    */ 
    public static void main(String[] args) 
    { 
     jmfcam05v jmfcam = new jmfcam05v(); 
    } 

    /** 
    * Constructor and processing method for image stream from a cam 
    * 
    */ 
    public jmfcam05v() 
    { 
     // Select webcam format 
     fetchDeviceFormats(); 
     camImgSel=0; // first format, or otherwise as desired 
     camFPS = 20; // framerate 

     // Setup data source 
     fetchDeviceDataSource(); 
     createPBDSource(); 
     createProcessor(dataSource); 
     startCapture(); 
     try{Thread.sleep(90000);}catch(Exception e){} // 20 seconds 
     stopCapture(); 
    } 

    /** 
    * Gathers info on a camera 
    * 
    */ 
    boolean fetchDeviceFormats() 
    { 
     Vector deviceList = CaptureDeviceManager.getDeviceList(new VideoFormat(null)); 
     CaptureDeviceInfo CapDevice = null; 
     Format CapFormat = null; 
     String type = "N/A"; 

     CaptureDeviceInfo deviceInfo=null;boolean VideoFormatMatch=false; 
     for(int i=0;i<deviceList.size();i++) 
     { 
      // search for video device 
      deviceInfo = (CaptureDeviceInfo)deviceList.elementAt(i); 
      if(deviceInfo.getName().indexOf("vfw:")<0)continue; 

      Format deviceFormat[] = deviceInfo.getFormats(); 
      for (int f=0;f<deviceFormat.length;f++) 
      { 
       if(deviceFormat[f] instanceof RGBFormat)type="RGB"; 
       if(deviceFormat[f] instanceof YUVFormat)type="YUV"; 
       if(deviceFormat[f] instanceof JPEGFormat)type="JPG"; 

       Dimension size = ((VideoFormat)deviceFormat[f]).getSize(); 
       camImgSize.addElement(type+" "+size.width+"x"+size.height); 

       CapDevice = deviceInfo; 
       camCapDevice.addElement(CapDevice); 
       //System.out.println("Video device = " + deviceInfo.getName()); 

       CapFormat = (VideoFormat)deviceFormat[f]; 
       camCapFormat.addElement(CapFormat); 
       //System.out.println("Video format = " + deviceFormat[f].toString()); 

       VideoFormatMatch=true; // at least one 
      } 
     } 
     if(VideoFormatMatch==false) 
     { 
      if(deviceInfo!=null)System.out.println(deviceInfo); 
      System.out.println("Video Format not found"); 
      return false; 
     } 

     return true; 
    } 

    /** 
    * Finds a camera and sets it up 
    * 
    */ 
    void fetchDeviceDataSource() 
    { 
     CaptureDeviceInfo CapDevice = (CaptureDeviceInfo)camCapDevice.elementAt(camImgSel); 
     System.out.println("Video device = " + CapDevice.getName()); 
     Format CapFormat = (Format)camCapFormat.elementAt(camImgSel); 
     System.out.println("Video format = " + CapFormat.toString()); 

     MediaLocator loc = CapDevice.getLocator(); 
     try 
     { 
      dataSource = Manager.createDataSource(loc); 
     } 
     catch(Exception e){} 

     try 
     { 
      // ensures 30 fps or as otherwise preferred, subject to available cam rates but this is frequency of windows request to stream 
      FormatControl formCont=((CaptureDevice)dataSource).getFormatControls()[0]; 
      VideoFormat formatVideoNew = new VideoFormat(null,null,-1,null,(float)camFPS); 
      formCont.setFormat(CapFormat.intersects(formatVideoNew)); 
     } 
     catch(Exception e){} 
    } 

    /** 
    * Gets a stream from the camera (and sets debug) 
    * 
    */ 
    void createPBDSource() 
    { 
     try 
     { 
      pbs=((PushBufferDataSource)dataSource).getStreams()[0]; 
     } 
     catch(Exception e){} 
    } 

    public void createProcessor(DataSource datasource) 
    { 
     FileTypeDescriptor ftd = new FileTypeDescriptor(FileTypeDescriptor.MSVIDEO); 
     Format[] formats = new Format[] {new VideoFormat(VideoFormat.INDEO50)}; 
     ProcessorModel pm = new ProcessorModel(datasource, formats, ftd); 
     try 
     { 
      processor = Manager.createRealizedProcessor(pm); 
     } 
     catch(Exception me) 
     { 
      System.out.println(me); 
      // Make sure the capture devices are released 
      datasource.disconnect(); 
      return; 
     } 
    } 

    private void startCapture() 
    { 
     // Get the processor's output, create a DataSink and connect the two. 
     DataSource outputDS = processor.getDataOutput(); 
     try 
     { 
      MediaLocator ml = new MediaLocator("file:capture.avi"); 
      datasink = Manager.createDataSink(outputDS, ml); 
      datasink.open(); 
      datasink.start(); 
     }catch (Exception e) 
     { 
      System.out.println(e); 
     } 
     processor.start(); 
     System.out.println("Started saving..."); 
    } 

    private void pauseCapture() 
    { 
     processor.stop(); 
    } 

    private void resumeCapture() 
    { 
     processor.start(); 
    } 

    private void stopCapture() 
    { 
     // Stop the capture and the file writer (DataSink) 
     processor.stop(); 
     processor.close(); 
     datasink.close(); 
     processor = null; 
     System.out.println("Done saving."); 
    } 
} 

這個計劃行之有效的Windows XP （桌面）和同治我嘗試使用它的Windows7（筆記本電腦），它給了我下面的錯誤：

run: Video Format not found 
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0 >= 0 
      at java.util.Vector.elementAt(Vector.java:427) 
      at jmfcam05v.fetchDeviceDataSource(jmfcam05v.java:112) 
      at jmfcam05v.<init>(jmfcam05v.java:49) 
      at jmfcam05v.main(jmfcam05v.java:34) Java Result: 1 BUILD SUCCESSFUL (total time: 0 seconds) 

我的程序是不是detectin上我的筆記本電腦的攝像頭inbuild也不是檢測cam.i正在使用外部網絡jmf捕獲視頻，我所有的攝像頭都支持vfw。 請幫我解決這個問題。

Answer 1

你在混合32位和64位安裝嗎？我在Windows 7下有類似的問題，這是由於Windows 7，JRE和JMF之間的64位不兼容。簡而言之，JMF只有32位，如果您的JRE是64位，則不會識別設備。

繼these instructions後，我能夠識別我的相機，並避免「視頻格式未找到」以及jmfstudio未檢測到視頻捕獲設備。

Answer 2

Windows 7安全性是否有可能阻止您訪問設備，因此您的列表在fetchDeviceDataSource（）調用中顯示爲空。

您可以嘗試turning off UAC並查看它是否修復您的問題。