请教个问题：我对网上的一个jfm的rtp视频聊天稍微改了点，在接收端就无法接受视频信息了，请问是怎么回事？如下：

package testRTP2;







import java.awt.Dimension;

import java.io.IOException;

import java.net.InetAddress;

import java.net.UnknownHostException;

import java.util.Vector;



import javax.media.CaptureDeviceInfo;

import javax.media.CaptureDeviceManager;

import javax.media.Codec;

import javax.media.Control;

import javax.media.Format;

import javax.media.Manager;

import javax.media.NoProcessorException;

import javax.media.Owned;

import javax.media.Processor;

import javax.media.control.FormatControl;

import javax.media.control.QualityControl;

import javax.media.control.TrackControl;

import javax.media.format.AudioFormat;

import javax.media.format.UnsupportedFormatException;

import javax.media.format.VideoFormat;

import javax.media.protocol.ContentDescriptor;

import javax.media.protocol.DataSource;

import javax.media.protocol.PushBufferDataSource;

import javax.media.protocol.PushBufferStream;

import javax.media.rtp.InvalidSessionAddressException;

import javax.media.rtp.RTPManager;

import javax.media.rtp.SendStream;

import javax.media.rtp.SessionAddress;



public class Sender {

	

	public static void main(String[] args) {	

		try {//设置本地地址和远端地址都为本机地址，自己传给自己，试验用

			SessionAddress local = new SessionAddress(InetAddress.getLocalHost(),50000);

			SessionAddress target = new SessionAddress(InetAddress.getLocalHost(),60000);		

			new Sender(local,target);

		} catch (UnknownHostException e) {

			e.printStackTrace();

		}		

	}



	public Sender(SessionAddress local,SessionAddress target) {

	

		 Vector<CaptureDeviceInfo> deviceList = CaptureDeviceManager.getDeviceList(null); 

		 CaptureDeviceInfo info = (CaptureDeviceInfo) deviceList.firstElement();

		 

//		CaptureDeviceInfo info=CaptureDeviceManager.getDevice(str);



		//CaptureDeviceInfo info = (CaptureDeviceInfo) CaptureDeviceManager.getDeviceList(null).get(0);

//		CaptureDeviceInfo info = (CaptureDeviceInfo) CaptureDeviceManager.getDeviceList(new AudioFormat(null)).get(0);用这一句替换上一句可改成音频传输

		Processor p = null;

		try {

			p = Manager.createProcessor(info.getLocator());

		} catch (NoProcessorException | IOException e) {

			e.printStackTrace();

		}

		StateHelper sh = new StateHelper(p);

		

		doSomeVideoProcess(p,sh);

//		doSomeAudioProcess(p,sh);用这一句替换上一句可改成音频传输

		RTPManager mgr = RTPManager.newInstance();//RTP管理器实例化

		try {//分别将本机和目的机IP地址加入至RTP会话管理器

			mgr.initialize(local);

			mgr.addTarget(target);

		} catch (InvalidSessionAddressException | IOException e) {

			e.printStackTrace();

		}

		

		DataSource ds = p.getDataOutput();

		PushBufferDataSource pbds = (PushBufferDataSource)ds;

	    PushBufferStream pbss[] = pbds.getStreams();

	   

	    for(int i=0;i<pbss.length;i++) {

			try {

				SendStream ss = mgr.createSendStream(ds, i);//产生第i条轨道的传输流

				ss.start();//传输流开始

			} catch (UnsupportedFormatException | IOException e) {

				e.printStackTrace();

			}

	    }

	    p.start();

	    try {

			Thread.sleep(60000);//传送一分钟后关闭

		} catch (InterruptedException e) {

			e.printStackTrace();

		}

	    if(p!=null) {

			p.stop();

			p.close();

		}

		if(mgr!=null) {

			mgr.removeTargets("client disconnnected");

			mgr.dispose();

			mgr = null;

		}

	}	

	private static void doSomeVideoProcess(Processor p,StateHelper sh) {

		sh.configure(5000);

		p.setContentDescriptor(new ContentDescriptor(ContentDescriptor.RAW_RTP));

		setVideoTrackFormat(p.getTrackControls());		

		sh.realize(5000);

		setJPEGQuality(p, 0.5f);

	}

	private static void doSomeAudioProcess(Processor p,StateHelper sh) {

		sh.configure(5000);

		p.setContentDescriptor(new ContentDescriptor(ContentDescriptor.RAW));

		setAudioTrackFormat(p.getTrackControls());		

		sh.realize(5000);

	}

	private static Format checkForVideoSizes(Format original, Format supported) {

	    int width, height;

	    Dimension size = ((VideoFormat)original).getSize();

	    Format jpegFmt = new Format(VideoFormat.JPEG_RTP);

	    Format h263Fmt = new Format(VideoFormat.H263_RTP);

	    if (supported.matches(jpegFmt)) {

	        // For JPEG, make sure width and height are divisible by 8.

	        width = (size.width % 8 == 0 ? size.width :

	                (int)(size.width / 8) * 8);

	        height = (size.height % 8 == 0 ? size.height :

	                (int)(size.height / 8) * 8);

	    } else if (supported.matches(h263Fmt)) {

	        // For H.263, we only support some specific sizes.

	        if (size.width < 128) {

		        width = 128;

		        height = 96;

	        } else if (size.width < 176) {

		        width = 176;

		        height = 144;

	        } else {

		        width = 352;

		        height = 288;

	        }

	    } else {

	    	// We don't know this particular format.  We'll just

	        // leave it alone then.

	        return supported;	        

	    }

	    return (new VideoFormat(null, 

                new Dimension(width, height), 

                Format.NOT_SPECIFIED,

                null,

                Format.NOT_SPECIFIED)).intersects(supported);

	}

	private static void setAudioTrackFormat(TrackControl[] trackControls) {

		boolean ok = false;

	    for(TrackControl t:trackControls){

	    	if(!ok && t instanceof FormatControl) {

	    		if(((FormatControl)t).setFormat(new AudioFormat(AudioFormat.ULAW_RTP,8000,8,1))==null) 

	    			t.setEnabled(false);

	    		 else 

	    			ok = true;	    		

	    	} else {

	    		t.setEnabled(false);

	    	}

	    }

	}

	private static boolean setVideoTrackFormat(TrackControl[] tracks) {

		if(tracks==null || tracks.length<1)

			return false;

		boolean atLeastOneTrack = false;

		for(TrackControl t:tracks) {

			if(t.isEnabled()) {

				Format[] supported = t.getSupportedFormats();

				Format chosen = null;

				if(supported.length>0) {

					if(supported[0] instanceof VideoFormat)

						chosen = checkForVideoSizes(t.getFormat(),supported[0]);

					else

						chosen = supported[0];					

					t.setFormat(chosen);

					atLeastOneTrack = true;

				} else {

					t.setEnabled(false);

				}

			} else {

				t.setEnabled(false);

			}

		}

		return atLeastOneTrack;

	}	

	private static void setJPEGQuality(Processor p, float val) {

		Control cs[] = p.getControls();

	    QualityControl qc = null;

	    VideoFormat jpegFmt = new VideoFormat(VideoFormat.JPEG);

	    // Loop through the controls to find the Quality control for

	    // the JPEG encoder.

	    for (int i = 0; i < cs.length; i++) {

	        if (cs[i] instanceof QualityControl && cs[i] instanceof Owned) {

	        Object owner = ((Owned)cs[i]).getOwner();

	        // Check to see if the owner is a Codec.

	        // Then check for the output format.

	        if (owner instanceof Codec) {

	            Format fmts[] = ((Codec)owner).getSupportedOutputFormats(null);

	            for (int j = 0; j < fmts.length; j++) {

		            if (fmts[j].matches(jpegFmt)) {

		                qc = (QualityControl)cs[i];

		                qc.setQuality(val);	                

		                break;

		            }

	            }

	        }

	        if (qc != null)

	            break;

	        }

	    }

	}

	

}