# rtpduphello.cpp

A basic example of how to use RTPDuplex

    // rtpduphello.
    // A very simple program for testing and illustrating basic features of ccRTP.
    // Copyright (C) 2001,2002  Federico Montesino <fedemp@altern.org>
    //
    // This program is free software; you can redistribute it and/or modify
    // it under the terms of the GNU General Public License as published by
    // the Free Software Foundation; either version 2 of the License, or
    // (at your option) any later version.
    //
    // This program is distributed in the hope that it will be useful,
    // but WITHOUT ANY WARRANTY; without even the implied warranty of
    // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    // GNU General Public License for more details.
    //
    // You should have received a copy of the GNU General Public License
    // along with this program; if not, write to the Free Software
    //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    // This is an introductory example file that illustrates basic usage
    // of ccRTP. You will also see a bit on how to use CommonC++ threads.

    // It is a typical hello world program. It consists of tow duplex
    // connections that talk each other through RTP packets. They do not
    // say more than a typical salutation message. They both send and
    // receive messages, and print the messages they receive.

    #include <cstdio>
    #include <cstdlib>
    // In order to use ccRTP, the RTP stack of CommonC++, you only need to
    // include ...
    #include <ccrtp/ext.h>

    #ifdef  CCXX_NAMESPACES
    using namespace ost;
    using namespace std;
    #endif

    class ccRTP_dupHello: public Thread
    {
    private:
        // There will be two duplex connections. They both will send
        // and receive packets.
        RTPDuplex *duplexA, *duplexB;

    public:
        // Destructor.
        ~ccRTP_dupHello()
        {
            terminate();
            delete duplexA;
            delete duplexB;
        }

        // Constructor.
        ccRTP_dupHello() : duplexA(NULL), duplexB(NULL)
            {}

        // This method does almost everything.
        void run(void)
        {
            // redefined from Thread.

            // Before using ccRTP you should learn something about other
            // CommonC++ classes. We need InetHostAddress...

            // Construct loopback address
            InetHostAddress local_ip;
            local_ip = "127.0.0.1";

            // Is that correct?
            if( ! local_ip ) {
            // this is equivalent to `! local_ip.isInetAddress()'
                cerr << ": IP address is not correct!" << endl;
                exit();
            }

            cout << local_ip.getHostname() <<
                " is going to talk to perself through " <<
                local_ip << "..." << endl;

            // ____Here comes the real RTP stuff____

            // Construct two RTPSocket. 22222 will be the base
            // port of A.  33334 will be the base port of B.
            const int A_BASE = 22222;
            const int B_BASE = 33334;

            duplexA = new RTPDuplex(local_ip,A_BASE,B_BASE);

            duplexB = new RTPDuplex(local_ip,B_BASE,A_BASE);

            // Set up A's connection
            duplexA->setSchedulingTimeout(90000);
            duplexA->setExpireTimeout(2500000);
            if( duplexA->connect(local_ip,B_BASE) < 0 )
                cerr << "Duplex A could not connect.";

            // Set up B's connection
            duplexB->setSchedulingTimeout(160000);
            duplexB->setExpireTimeout(3500000);
            if( duplexB->connect(local_ip,A_BASE) < 0 )
                cerr << "Duplex B could not connect.";

            // Let's check the queues  (you should read the documentation
            // so that you know what the queues are for).

            if( duplexA->RTPDataQueue::isActive() )
                cout << "The queue A is active." << endl;
            else
                cerr << "The queue  A is not active." << endl;

            if( duplexB->RTPDataQueue::isActive() )
                cout << "The queue B is active." << endl;
            else
                cerr << "The queue B is not active." << endl;

            cout << "Transmitting..." << endl;

            // This message will be sent on RTP packets, from A to
            // B and from B to A.
            unsigned char helloA[] = "Hello, brave gnu world from A!";
            unsigned char helloB[] = "Hello, brave gnu world from B!";

            // This is not important
            time_t sending_time;
            time_t receiving_time;
            char tmstring[30];

            StaticPayloadFormat pf = sptMP2T;
            duplexA->setPayloadFormat(pf);
            duplexB->setPayloadFormat(pf);

            // This is the main loop, where packets are sent and receipt.
            // A and B both will send and receive packets.
            for( int i = 0 ; true ; i++ ) {

                // A and B do almost exactly the same things,
                // I have kept this here -out of a send/receive
                // method- in the interest of clarity.

                // A: Send an RTP packet
                sending_time = time(NULL);
                duplexA->putData(2*(i)*90000,helloA,
                          strlen((char *)helloA));
                // Tell it
                strftime(tmstring,30,"%X",localtime(&sending_time));
                cout << "A: sending message at " << tmstring << "..."
                     << endl;

                // A: Receive an RTP packet
                receiving_time = time(NULL);
                const AppDataUnit* aduA =
                    duplexA->getData(duplexA->getFirstTimestamp());
                if ( aduA ) {
                    // Tell it
                    strftime(tmstring,30,"%X",localtime(&receiving_time));
                    cout << "A:[receiving at " << tmstring << "]: " <<
                        aduA->getData() << endl;
                }
                // Wait for 0.1 seconds
                Thread::sleep(100);

                // B: Send an RTP packet
                sending_time = time(NULL);
                duplexB->putData(2*(i)*90000,helloB,
                         strlen((char *)helloB));
                // Tell it
                strftime(tmstring,30,"%X",localtime(&sending_time));
                cout << "B: sending message at " << tmstring << "..."
                     << endl;

                // B: Receive an RTP packet
                receiving_time = time(NULL);
                const AppDataUnit* aduB =
                    duplexB->getData(duplexB->getFirstTimestamp());
                if ( aduB ) {
                    // Tell it
                    strftime(tmstring,30,"%X",localtime(&receiving_time));
                    cout << "B:[receiving at " << tmstring << "]: " <<
                        aduB->getData() << endl;
                }

                Thread::sleep(1900);
            }

        }
    };

    int main(int argc, char *argv[])
    {
        // Construct the main thread. It will not run yet.
        ccRTP_dupHello *hello = new ccRTP_dupHello;

        cout << "This is rtpduphello, a very simple test program for ccRTP."
             << endl << "Strike [Enter] when you are fed up." << endl;

        // Start execution of hello.
        hello->start();

        cin.get();

        cout << endl << "That's all" << endl;

        delete hello;

        exit(0);
    }