📅  最后修改于: 2023-12-03 15:09:27.065000             🧑  作者: Mango
实时传输协议(Real-time Transfer Protocol,简称RTP)是用于实时传输音频、视频和其他流媒体数据的协议。RTP可以提供即时性和容错性,支持多媒体数据的多路复用和分离等操作。
RTP具有以下特点:
RTP数据包主要包含如下几个部分:
RTP在实时传输领域被广泛应用,例如:
在Java中,RTP的实现可以使用Java Media Framework(JMF)或者使用第三方库,例如JRTPLIB。
以下是使用JMF实现一个简单的RTP发送器的示例代码:
import java.net.*;
import javax.media.*;
import javax.media.rtp.*;
import javax.media.protocol.*;
public class RTPSender {
private Processor processor = null;
private MediaLocator mediaLocator = null;
private RTPManager rtpManager = null;
private SessionAddress localAddress = null;
private SessionAddress remoteAddress = null;
public RTPSender(String mediaFileName, String ipAddress, int port) {
mediaLocator = new MediaLocator("file:" + mediaFileName);
try {
processor = Manager.createProcessor(mediaLocator);
processor.configure();
while (processor.getState() != Processor.Configured) {
Thread.sleep(50);
}
processor.setContentDescriptor(new ContentDescriptor(ContentDescriptor.RAW_RTP));
TrackControl trackControl[] = processor.getTrackControls();
Format format[] = new Format[trackControl.length];
for (int i = 0; i < trackControl.length; i++) {
format[i] = trackControl[i].getFormat();
trackControl[i].setFormat(new RTPFormat(format[i]));
}
processor.realize();
while (processor.getState() != Processor.Realized) {
Thread.sleep(50);
}
rtpManager = RTPManager.newInstance();
rtpManager.addReceiveStreamListener(new MyReceiveStreamListener());
rtpManager.addSessionListener(new MySessionListener());
rtpManager.initialize(localAddress);
InetAddress ip = InetAddress.getByName(ipAddress);
remoteAddress = new SessionAddress(ip, port);
rtpManager.addTarget(remoteAddress);
processor.start();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
RTPSender sender = new RTPSender("example.mp4", "192.168.1.101", 12345);
}
class MySessionListener implements SessionListener {
public void update(SessionEvent event) {
if (event instanceof NewParticipantEvent) {
System.out.println("new participant");
}
}
}
class MyReceiveStreamListener implements ReceiveStreamListener {
public void update(ReceiveStreamEvent event) {
if (event instanceof RemotePayloadChangeEvent) {
System.out.println("remote payload changed");
}
}
}
class RTPFormat extends Format {
private static final long serialVersionUID = 1L;
public RTPFormat(Format format) {
super(format);
}
@Override
public RTPFormat matches(Format format) {
if (format instanceof RTPFormat) {
return (RTPFormat) format;
}
return null;
}
}
}