Creating +and Managing an RTP session

This page describes how to create a new session with the socket server +and how to open the session and set some of the session parameters. It also +describes how to use an RTP RSocket interface.

To communicate with RTP, open a session with the socket +server. You can open several sessions at the same time.

An active scheduler must +be created and started before you open an RTP session.

Opening a session

RRtpSession::OpenL() opens +an RTP session and starts it. The method has four overloads. RTCP is enabled +for the first three overloads and is disabled for the last overload.

IMPORT_C void OpenL(RSocketServ &aServer, TSockAddr &aLocalAddr, TSockAddr &aRemoteAddr, TInt aMaxRXSize, RConnection &aConnection, TInt aPriority=EPriorityNormal, const TDesC8 &aCNAME=KNullDesC8); IMPORT_C void OpenL(RSocketServ &aServer, TSockAddr &aLocalAddr, TSockAddr &aRemoteAddr, TInt aMaxRXSize, TInt aPriority=EPriorityNormal, const TDesC8 &aCNAME=KNullDesC8); IMPORT_C void OpenL(RSocket &aSocket, TInt aMaxRXSize, RSocket &aRtcpSocket, TInt aPriority=EPriorityNormal, const TDesC8 &aCNAME=KNullDesC8); IMPORT_C void OpenL(RSocket &aSocket, TInt aMaxRXSize, TInt aPriority=EPriorityNormal);

Setting session parameters

After +creating an RTP session, you need to set the following parameters before sending +and receiving RTP packets:

the bandwidth for the +RTP stream, by calling the SetBandwidth() method
the conversion rate +for the RTCP timestamp, by calling the SetRTPTimeConversion() method

During an active RTP session, you can change the following parameters:

the destination address, +by calling the SetRemoteAddress() method
the remote RTCP port, +by calling the SetRemoteRtcpPort() method

When specifying a new remote address for the RTP session, the remote +RTCP port is set one port higher than the RTP port, as defined by the RTP +standard. When specifying a new RTCP port, the RTP port is not modified.

Note: +If you need more configuration options for your RTP communications, you can +change the settings of the internal sockets. The RtpSocket() and RtcpSocket() methods return the handles of +the internal sockets used for RTP and RTCP data.

Example

The following code shows how to create +a new session, and set session parameters.

// [...] + +// Construct a new session object +RRtpSession session; +session.OpenL(iRtpSocket, 1500, EPriorityNormal); + +// Set the RTP session parameters +session.SetBandwidth(1000); // Set session bandwidth in bps at the start up + +//SetRTPTimeConversion API is called before receiving an RTP packet +session.SetRTPTimeConversion(100, 100); // Set RTP time conversion for generating the RTP timestamps in RTCP packets +

The following code shows how to change parameters during the +RTP session:

+// sample address and port for the RTP socket +TSockAddr newAddr; +newAddrr.SetAddress(INET_ADDR(192,168,0,1)); +newAddr.SetPort(4646); + +// changing the RTP destination +session.SetRemoteAddress(newAddr); + +// by default, the RTCP port is set to the first port higher than the RTP port +session.SetRemoteRtcpPort(4649); + +// turning IMCP errors onsession. +RtpSocket().SetOpt(KSoUdpReceiveICMPError, KSolInetUdp, 1); +