// audiotx. // A simple and amusing program for testing basic features of ccRTP. // Copyright (C) 2001 Federico Montesino <p5087@quintero.fie.us.es> // // 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 and // TimerPort. // I am a transmitter of \mu-law encoded RTP audio packets. In order // to hear what I transmit, you should be running my colleague // `audiorx'. You can give me the name of a .au file as argument. // In order to use ccRTP, the RTP stack of CommonC++, you only need to // include ... #include <cc++/rtp.h> // Some consts common to audiotx and audiorx #include <audio.h> #include <cstdio> #include <cstdlib> class ccRTP_AudioTransmitter: public Thread, public TimerPort { private: // This is the descriptor of the file we will read from // (commonly, /dev/audio or a .au file) int audioinput; // If we are sending a .au file bool sendingfile; // The aforementioned file will be transmitted through this socket RTPSocket *socket; public: // Constructor. If it is given a file name, this thread will // transmit that file. If it is not, /dev/audio input is // transmitted ccRTP_AudioTransmitter(char *filename=""){ if( !strcmp(filename,"") ){ filename="/dev/audio"; sendingfile = false; }else{ sendingfile = true; } audioinput=open(filename,O_RDONLY|O_NDELAY); if( audioinput >= 0 ){ cout << "Ready to transmit " << filename << "." <<endl; }else{ cout << "I could not open " << filename << "." << endl; exit(0); } socket=NULL; } // Destructor. ~ccRTP_AudioTransmitter(){ Terminate(); if( socket ) delete socket; close(audioinput); } // 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(1); } cout << local_ip.getHostname() << " is going to transmit audio to perself through " << local_ip << "..." << endl; // ____Here comes the real RTP stuff____ // Construct the RTP socket. socket = new RTPSocket(local_ip,TRANSMITTER_BASE,0); // Set up connection socket->setTimeout(10000); socket->setExpired(1000000); if( socket->Connect(local_ip,RECEIVER_BASE) < 0 ) cerr << "I could not connect."; // Let's the queue (you should read the documentation // so that you know what the queue is for). cout << "The RTP queue is "; if( socket->RTPQueue::isActive() ) cout << "active." << endl; else cerr << "not active." << endl; cout << "Transmitting " << PACKET_SIZE << " octects long packets " << "every " << PERIOD << " milliseconds..." << endl; unsigned char buffer[PACKET_SIZE]; int count=PACKET_SIZE; // This will be useful for periodic execution TimerPort::setTimer(PERIOD); setCancel(THREAD_CANCEL_IMMEDIATE); // This is the main loop, where packets are transmitted. for( int i=0 ; (!sendingfile || count > 0) ; i++ ){ count=read(audioinput,buffer,PACKET_SIZE); if( count > 0 ){ // send an RTP packet, providing timestamp, // payload type and payload. socket->putPacket(PACKET_SIZE*i, RTP_PAYLOAD_PCMU, buffer, PACKET_SIZE); } cout << "."<<flush; // Let's wait for the next cycle ccxx_sleep(TimerPort::getTimer()); TimerPort::incTimer(PERIOD); } cout << endl << "I have got no more data to send. " <<endl; } // end of Run }; void main(int argc, char *argv[]){ cout << "This is audiotx, a simple test program for ccRTP." << endl; cout << "You should have run audiorx (the server/receiver) before." << endl; cout << "Strike [Enter] when you are fed up. Enjoy!." << endl; ccRTP_AudioTransmitter *transmitter; // Construct the main thread. It will not run yet. if ( argc == 2 ) transmitter = new ccRTP_AudioTransmitter(argv[1]); else transmitter = new ccRTP_AudioTransmitter(); // Start transmission now. transmitter->Start(); cin.get(); cout << endl << "That's all." << endl; delete transmitter; exit(0); }