我是使用 RTP 进行 SIP 呼叫的新手，现在我正在尝试使用 RTP 发送和接收语音流进行 sip 呼叫。我完成了连接两个模拟器的工作，并且能够使用 jain sip 发送 INVITE 和 INVITE-ACK。
收到 Ack 后，我想为媒体流启动 RTP，我使用 RtpPacket 函数发送和接收
我RtpFunction用来发送带有所有 RTP 标头的媒体，如下所示：
byte Version;
boolean Padding;
boolean Extension;
byte CC;
boolean Marker;
byte PayloadType;
short SequenceNumber;
int TimeStamp;
请提供一些想法和实际链接，我可以在其中找到答案。
这可以以更简单的方式实现
AudioManager audio = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
audio.setMode(AudioManager.MODE_IN_COMMUNICATION);
audioGroup = new AudioGroup();
audioGroup.setMode(AudioGroup.MODE_ECHO_SUPPRESSION);
audioStream = new AudioStream(InetAddress.getByAddress(getLocalIPAddress()));
audioStream.setCodec(AudioCodec.PCMU);
audioStream.setMode(RtpStream.MODE_NORMAL);
audioStream.associate(InetAddress.getByName(SipStackAndroid.getRemoteIp()), REMOTE_PORT);
audioStream.join(audioGroup);
我们使用 RTPpacket 发送和接收 RTP 数据。
import javax.media.rtp.*;
import javax.media.rtp.rtcp.*;
import javax.media.rtp.event.*;
import javax.media.*;
import javax.media.protocol.*;
import java.net.InetAddress;
import javax.media.format.AudioFormat;
import com.sun.media.ui.*;
import java.util.Vector;
public class RTPSourceStream < RTPPlayerWindow > implements ReceiveStreamListener,
ControllerListener {
@SuppressWarnings("rawtypes")
Vector playerlist = new Vector();
@SuppressWarnings("deprecation")
SessionManager mgr = null;
boolean terminatedbyClose = false;
@SuppressWarnings("deprecation")
public SessionManager createManager(String address,
String sport,
String sttl,
boolean listener,
boolean sendlistener) {
return createManager(address,
new Integer(sport).intValue(),
new Integer(sttl).intValue(),
listener,
sendlistener);
}
@SuppressWarnings("deprecation")
public SessionManager createManager(String address,
int port,
int ttl,
boolean listener,
boolean sendlistener) {
mgr = (SessionManager) new com.sun.media.rtp.RTPSessionMgr();
if (mgr == null) return null;
mgr.addFormat(new AudioFormat(AudioFormat.DVI_RTP, 44100, 4, 1), 18);
if (listener) mgr.addReceiveStreamListener(this);
// if (sendlistener) new RTPSendStreamWindow(mgr);
// ask RTPSM to generate the local participants CNAME
String cname = mgr.generateCNAME();
String username = null;
try {
username = System.getProperty("user.name");
} catch (SecurityException e) {
username = "jmf-user";
}
// create our local Session Address
SessionAddress localaddr = new SessionAddress();
try {
InetAddress destaddr = InetAddress.getByName(address);
SessionAddress sessaddr = new SessionAddress(destaddr,
port,
destaddr,
port + 1);
SourceDescription[] userdesclist = new SourceDescription[] {
new SourceDescription(SourceDescription
.SOURCE_DESC_EMAIL,
"jmf-user@sun.com",
1,
false),
new SourceDescription(SourceDescription
.SOURCE_DESC_CNAME,
cname,
1,
false),
new
SourceDescription(SourceDescription.SOURCE_DESC_TOOL, "JMF RTP Player v2.0",
1,
false)
};
mgr.initSession(localaddr,
userdesclist,
0.05,
0.25);
mgr.startSession(sessaddr, ttl, null);
} catch (Exception e) {
System.err.println(e.getMessage());
return null;
}
return mgr;
}
public void update(ReceiveStreamEvent event) {
Player newplayer = null;
RTPPacket playerWindow = null;
// find the sourceRTPSM for this event
SessionManager source = (SessionManager) event.getSource();
// create a new player if a new recvstream is detected
if (event instanceof NewReceiveStreamEvent) {
String cname = "Java Media Player";
ReceiveStream stream = null;
try {
// get a handle over the ReceiveStream
stream = ((NewReceiveStreamEvent) event)
.getReceiveStream();
Participant part = stream.getParticipant();
if (part != null) cname = part.getCNAME();
// get a handle over the ReceiveStream datasource
DataSource dsource = stream.getDataSource();
// create a player by passing datasource to the
// Media Manager
newplayer = Manager.createPlayer(dsource);
System.out.println("created player " + newplayer);
} catch (Exception e) {
System.err.println("NewReceiveStreamEvent exception " +
e.getMessage());
return;
}
if (newplayer == null) return;
playerlist.addElement(newplayer);
newplayer.addControllerListener(this);
// send this player to player GUI
playerWindow = new RTPPacket(newplayer, cname);
}
}
public void controllerUpdate(ControllerEvent evt) {
// get a handle over controller, remove it from the player
// list.
// if player list is empty, close the sesssion manager.
if ((evt instanceof ControllerClosedEvent) ||
(evt instanceof ControllerErrorEvent) ||
(evt instanceof DeallocateEvent)) {
Player p = (Player) evt.getSourceController();
if (!terminatedbyClose) {
if (playerlist.contains(p))
playerlist.removeElement(p);
if ((playerlist.size() == 0) && (mgr != null))
mgr.closeSession("All players are closed");
}
}
}
public void closeManager() {
terminatedbyClose = true;
// first close all the players
for (int i = 0; i < playerlist.size(); i++) {
((Player) playerlist.elementAt(i)).close();
}
if (mgr != null) {
mgr.closeSession("RTP Session Terminated");
mgr = null;
}
}
class RTPPacket extends RTPSourceStream {
public RTPPacket(Player newplayer, String cname) {
// TODO Auto-generated constructor stub
}
}
}