java - 当我使用 jmf 流式传输时，为什么在 Wireshark 中是 UDP，而不是 RTP？

Question

我想使用 JMF 2.1.1e 以 RTP 格式捕获和流式传输音频。我写了一个简单的发送器，我可以发送和接收音频。但是当我在 Wireshark 中看到时，我看到数据包是 UDP。请任何人指出我的问题。

这是我负责音频捕获和传输的功能。

public void captureAudio(){

    // Get the device list for ULAW
    Vector devices = captureDevices();

    CaptureDeviceInfo captureDeviceInfo = null;

    if (devices.size() > 0) {
         //get the first device from the list and cast it as CaptureDeviceInfo
         captureDeviceInfo = (CaptureDeviceInfo) devices.firstElement();
    }
    else {
        // exit if we could not find the relevant capturedevice.
        System.out.println("No such device found");
        System.exit(-1);
    }


    Processor processor = null;
    try {
        //Create a Processor for the specified media.
        processor = Manager.createProcessor(captureDeviceInfo.getLocator());
    } catch (IOException ex) {
        System.err.println(ex);
    } catch (NoProcessorException ex) {
        System.err.println(ex);
    }
    //Prepares the Processor to be programmed.
    //puts the Processor into the Configuring state.
    processor.configure();

    //Wait till the Processor configured.
    while (processor.getState() != Processor.Configured){
       try {
           Thread.sleep(100);
       } catch (InterruptedException e) {
           e.printStackTrace();
       }
   }


    //Sets the output content-type for this Processor
    processor.setContentDescriptor(CONTENT_DESCRIPTOR); 
    /** 
         ContentDescriptor CONTENT_DESCRIPTOR
                = new ContentDescriptor(ContentDescriptor.RAW_RTP); 
      */

    //Gets a TrackControl for each track in the media stream.
    TrackControl track[] = processor.getTrackControls();

    boolean encodingOk = false;

    //searching through tracks to get a supported audio format track.
    for (int i = 0; i < track.length; i++) {
        if (!encodingOk && track[i] instanceof FormatControl) {
            if (((FormatControl)
                    track[i]).setFormat( new AudioFormat(AudioFormat.ULAW_RTP, 8000, 8, 1) ) == null)
            {
               track[i].setEnabled(false);
            }
            else {
                encodingOk = true;
                track[i].setEnabled(encodingOk);
                System.out.println("enc: " + i);
            }
        } else {
            // we could not set this track to ULAW, so disable it
            track[i].setEnabled(false);
        }
    }

    //If we could set this track to ULAW we proceed
    if (encodingOk){            
        processor.realize();
        while (processor.getState() != Processor.Realized){
           try {
               Thread.sleep(100);
           } catch (InterruptedException e) {
               e.printStackTrace();
           }
        }

        DataSource dataSource = null;
        try {
            dataSource = processor.getDataOutput();
        } catch (NotRealizedError e) {
            e.printStackTrace();
        }

        try {

            String url= "rtp://192.168.1.99:49150/audio/1";
            MediaLocator m = new MediaLocator(url);
            DataSink d = Manager.createDataSink(dataSource, m);
            d.open();
            d.start();
            System.out.println("transmitting...");
            processor.start();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

如果您发现任何不当或模糊之处，请询问。提前致谢。 :)

说明:我有一段用于 RTP 流式传输的 C# 代码。当我使用 wireshark 捕获数据时，我可以将它们视为 RTP，但问题是当我从 JMF wireshark 捕获数据流时将它们显示为 UDP。我的问题是，为什么？

我知道UDP和RTP的区别。

Answer 1

RTP是应用层，UDP是传输层，那不是一个级别的!维基百科有助于详细解释这一点。因此，您的数据在 UDP“帧”中作为 RTP 流发送

小概览...

应用层:

* DHCP
* DHCPv6
* DNS
* FTP
* HTTP
* IMAP
* IRC
* LDAP
* MGCP
* NNTP
* BGP
* NTP
* POP
* RPC
* RTP
* RTSP
* RIP
* SIP
* SMTP
* SNMP
* SOCKS
* SSH
* Telnet
* TLS/SSL
* XMPP
* (more)

传输层

* TCP
* UDP
* DCCP
* SCTP
* RSVP
* (more)

互联网层

* IP
      o IPv4
      o IPv6
* ICMP
* ICMPv6
* ECN
* IGMP
* IPsec
* (more)

链接层

* ARP/InARP
* NDP
* OSPF
* Tunnels
      o L2TP
* PPP
* Media access control
      o Ethernet
      o DSL
      o ISDN
      o FDDI
* (more)