RTPExample: RTP Packet Streaming Example

Description

This example code demonstrates RTP packet streaming. It uses CRtpFileSender to send RTP packets and CRtpFileStreamer to receive RTP packets. The example opens an RTP session using the pre-connected socket and initialises new send and receive sources on the RTP session. It registers the callback functions when an RTP packet is successfully sent by a send source or received by a receive source, to receive notifications whenever an RTP packet is sent or received.

The RTPExample example code provides the following functionality:

Download

Click on the following link to download the example: RTPExample.zip

Click browse to view the example code.

Initialising

       
        
       
       void CRtpFileStreamer::ConstructL();
      

Opens an RTP session using the pre-connected socket and initialises new send sources on the RTP session.

Sending an RTP packet

       
        
       
       void CRtpFileSender::RunL();
      

Sends the RTP packet. This does the following:

  • gets a new RTP packet to send from the send source

  • sets the RTP timestamp of the RTP packet

  • reads a block of data from the source file

  • creates an RTP packet using the block of data

  • sends the RTP packet

  • closes the source file.

CRtpFileSender::PacketSent() is called to notify that the RTP packet has been successfully sent.

Receiving an RTP packet

       
        
       
       void CRtpFileStreamer::NewSource();
      

When an RTP packet with a new receive source arrives, this callback function is called, which registers the packet. This can be used for different types of RTP packets such as APP, BYE, SDES, SR and RR.

       
        
       
       void CRtpFileStreamer::PacketArrived();
      

Whenever an RTP packet arrives, this callback function is called. The function retrieves the payload from the packet received and writes it to the target file.

Usage

The Symbian build process describes how to build an application.

This is a console application, so does not have a GUI. It builds an executable called RTPExample.exe in the standard location ( \epoc32\release\winscw\ <build_variant> for CodeWarrior). After launching the executable, depending on the emulator you are using, you may need to task away from the app launcher/shell screen to view the console.