This section includes the following sample programs for RTP:
-
sender.c
When the user requests, the sender.c program sends an RTP packet.
-
recver.c
When the user requests, the recver.c program polls for an RTP packet and receives the packet.
The usage of these programs is as follows:
./sender [-a local-address] [-p local-rtp-port] [-d dest-addr] [-r remote-rtp-port]
./recver [-a local-address] [-p local-rtp-port] [-d dest-addr] [-r remote-rtp-port]
Example:
./sender
or
./sender -p 8200 -r 7100
./recver
or
./recver -p 7100 -r 8200
| |
The sender.c Program
|
|
The sender.c program is as follows:
|
|
/*
* HP MSP-RTP Sample application
* (c) Copyright 2003 Hewlett-Packard Company All Rights Reserved
*
*/
#include <netinet/in.h>
#include <rtp.h>
/*
* This Application uses the interfaces provided by the
* RTP library to transmit data
*
*/
/* Macros for handling time as double */
#define tv2dbl(tv) ((tv).tv_sec + (tv).tv_usec / 1000000.0)
#define dbl2prnt(x) ((int)((long)(x))) \
,((int)(((int)(1000000.0*((double)(x))))%((int)1000000)))
/* function to print Usage for this program */
Usage(char *prg)
{
fprintf(stderr, "Usage: %s [-a local-address] [-p local-rtp-port]"
" [-d dest-addr] [-r remote-rtp-port]\n",prg);
}
/* The main routine */
int main(int argc, char **argv)
{
char c;
/*
* by default:
* IPv4 is to be handled unless specified
* local ports 28000 for RTP and 28001 for RTCP are used
* loop back addresses are used
*/
int RTPport=28000,RTCPport;
int remRTPport=17000,remRTCPport;
char *caddr="127.0.0.1",*destaddr="127.0.0.1";
struct sockaddr_in addr[2];
int rd;
int ret;
struct sockaddr_in sin;
int i=0,x;
char ec='y';
while ((c = getopt(argc, argv, "6a:p:d:r:"))!=EOF)
{
switch(c)
{
case 'a':
caddr=optarg;
break;
case 'p':
RTPport=atoi(optarg);
break;
case 'r':
remRTPport=atoi(optarg);
break;
case 'd':
destaddr=optarg;
break;
default:
{
Usage(argv[1]);
exit(1);
}
}
}
RTCPport = RTPport + 1;
addr[0].sin_family=AF_INET;
inet_pton(AF_INET,caddr,&addr[0].sin_addr.s_addr);
addr[0].sin_port=RTPport;
addr[1].sin_family=AF_INET;
inet_pton(AF_INET,caddr,&addr[1].sin_addr.s_addr);
addr[1].sin_port=RTCPport;
rd = rtp_open((char*)addr, (char*)(addr+1));
if(rd>0)
{
printf("\tOpened RTP descriptor %d\n"
"\tReceiving RTP packets on port %d\n"
"\tand RTCP packets on port %d\n"
,rd
,addr[0].sin_port
,addr[1].sin_port
);
}
else
{
fprintf(stderr,"rtp_open() failed\n");
exit(1);
}
remRTCPport=remRTPport+1;
sin.sin_family=AF_INET;
sin.sin_port=remRTPport;
sin.sin_addr.s_addr=inet_addr(destaddr);
if(sin.sin_addr.s_addr < 0)
{
fprintf(stderr,"The destination address %s is not valid\n",destaddr);
exit(1);
}
ret = rtp_ioctl(rd,RTP_SSENDTOADDR,&sin);
if(ret<0)
{
fprintf(stderr,"could not add %s to the RTP SENDTO list\n",destaddr);
}
else
printf("\tDestination %s:%d addded to RTP SENDTO list\n"
,destaddr
,remRTPport
);
sin.sin_port=remRTCPport;
ret = rtp_ioctl(rd,RTCP_SSENDTOADDR,&sin);
if(ret<0)
{
fprintf(stderr,"could not add %s to the RTCP SENDTO list\n",destaddr);
}
else
printf("\tDestination %s:%d addded to RTCP SENDTO list\n"
,destaddr
,remRTCPport
);
/*
* constructing an RTP packet
* The RTP packet which we construct does not contain
* actual media data, but contains alphabets.
* Media streaming applications would replace this
* with actual media packets.
*/
rtp_pkt_t pkt ;
pkt.v=2;
pkt.p=0;
pkt.x=0;
pkt.cc=0;
pkt.m=1;
pkt.pt=7;
pkt.seq=1;
struct timeval tv;
struct timezone tzp;
gettimeofday(&tv,&tzp);
pkt.ts=tv2dbl(tv);
pkt.csrcp=0;
pkt.xtnhdrp=0;
pkt.datap=(char*)malloc(9);
strcpy(pkt.datap,"abcdefgh",8);
pkt.datalen=8;
i=0;
printf("send an RTP packet? ");
fflush(stdin);
scanf("%c",&ec);
/*
* The library automatically generates RTCP packets.
*/
while((ec=='y')||(ec=='Y'))
{
i++;
if((ret= rtp_send(rd,&pkt))<0) break;
printf("send another packet? ");
fflush(stdin);
scanf("%c",&ec);
}
if(ret<0)
printf("rtp_send failed \n");
else
printf("%d RTP packet(s) sent\n",i);
}
|
|
|
| |
The recver.c Program
|
|
|
The recver.c program is as follows:
|
|
/*
* HP MSP-RTP Sample application
* (c) Copyright 2003 Hewlett-Packard Company All Rights Reserved.
*
*/
#include <netinet/in.h>
#include <rtp.h>
/*
* This Application uses the interfaces provided by the
* RTP library to transmit data
*
*/
/* Macros for handling time as double */
#define tv2dbl(tv) ((tv).tv_sec + (tv).tv_usec / 1000000.0)
#define dbl2prnt(x) ((int)((long)(x))) \
,((int)(((int)(1000000.0*((double)(x))))%((int)1000000)))
/* function to print Usage for this program */
Usage(char *prg)
{
fprintf(stderr, "Usage: %s [-a local-address] [-p local-rtp-port]"
" [-d dest-addr] [-r remote-rtp-port]\n",prg);
}
/* The main routine */
int main(int argc, char **argv)
{
char c;
/*
* by default:
* IPv4 is to be handled unless specified
* local ports 17000 for RTP and 17001 for RTCP are used
* loop back addresses are used
*/
int RTPport=17000,RTCPport;
int remRTPport=28000,remRTCPport;
char *caddr="127.0.0.1",*destaddr="127.0.0.1";
struct sockaddr_in addr[2];
int rd;
int ret;
struct sockaddr_in sin;
int i=0,x;
char ec='y';
struct rtp_pollrd rfds[1];
char buf[1024],*ptr=buf;
while ((c = getopt(argc, argv, "6a:p:d:r:"))!=EOF)
{
switch(c)
{
case 'a':
caddr=optarg;
break;
case 'p':
RTPport=atoi(optarg);
break;
case 'r':
remRTPport=atoi(optarg);
break;
case 'd':
destaddr=optarg;
break;
default:
{
Usage(argv[1]);
exit(1);
}
}
}
RTCPport = RTPport + 1;
addr[0].sin_family=AF_INET;
inet_pton(AF_INET,caddr,&addr[0].sin_addr.s_addr);
addr[0].sin_port=RTPport;
addr[1].sin_family=AF_INET;
inet_pton(AF_INET,caddr,&addr[1].sin_addr.s_addr);
addr[1].sin_port=RTCPport;
rd = rtp_open((char*)addr, (char*)(addr+1));
if(rd>0)
{
printf("\tOpened RTP descriptor %d\n"
"\tReceiving RTP packets on port %d\n"
"\tand RTCP packets on port %d\n"
,rd
,addr[0].sin_port
,addr[1].sin_port
);
}
else
{
fprintf(stderr,"rtp_open() failed\n");
exit(1);
}
remRTCPport=remRTPport+1;
sin.sin_family=AF_INET;
sin.sin_port=remRTPport;
sin.sin_addr.s_addr=inet_addr(destaddr);
if(sin.sin_addr.s_addr < 0)
{
fprintf(stderr,"The destination address %s is not valid\n",destaddr);
exit(1);
}
ret = rtp_ioctl(rd,RTP_SSENDTOADDR,&sin);
if(ret<0)
{
fprintf(stderr,"could not add %s to the RTP SENDTO list\n",destaddr);
}
else
printf("\tDestination %s:%d addded to RTP SENDTO list\n"
,destaddr
,remRTPport
);
sin.sin_port=remRTCPport;
ret = rtp_ioctl(rd,RTCP_SSENDTOADDR,&sin);
if(ret<0)
{
fprintf(stderr,"could not add %s to the RTCP SENDTO list\n",destaddr);
}
else
printf("\tDestination %s:%d addded to RTCP SENDTO list\n"
,destaddr
,remRTCPport
);
/*
* The library automatically generates RTCP packets.
*/
/* poll for an RTP packet */
printf("polling for an RTP packet...\n");
rfds[0].rd=rd;
rfds[0].events=RTP_PIN;
if((ret=rtp_poll(rfds,1,-1))<0)
{
fprintf(stderr,"rtp_poll() failed\n");
exit(1);
}
printf("An RTP packet is ready to be received \n"
"Receive it now?");
fflush(stdin);
scanf("%c",&ec);
i=0;
int buflen;
while((ec!='n')&&(ec!='N'))
{
i++;
buflen=sizeof buf;
/*
* receiving an RTP packet
* if ptr points to NULL instead of buf the
* library would automatically allocate the
* required memory for the RTP packet.
*/
if((ret= rtp_recv(rd,(rtp_pkt_t *)NULL,&ptr,&buflen))<0) break;
printf("receive another packet? ");
fflush(stdin);
scanf("%c",&ec);
}
if(ret<0)
{
/*
* if memory were requested from the library
* a check for RTP_EMOREDATA would have been
* redundant
*/
if(ret==RTP_EMOREDATA)
fprintf(stderr,"The buffer passed to rtp_recv() was small\n");
else
fprintf(stderr,"rtp_recv() failed \n");
}
else
printf("%d RTP packet(s) received\n",i);
}
|
|
|
| |
Make File
|
|
|
The make file for RTP is as follows:
all : sender recver
sender: sender.c
cc -O sender.c -o sender -l rtp
recver: recver.c
cc -O recver.c -o recver -l rtp
|
| |
Compiling the Sample RTP Program
|
|
|
This section describes how to compile the sample RTP program.
Before compiling the program, ensure that the rtp.h header file and the librtp library that come with HP-UX MSP are available on the machine. The rtp.h header file is assumed to be in the /usr/include directory and the librtp library in the /usr/lib directory.To compile, issue the following commands:
$ cc recver.c -o recver -lrtp
$ cc sender.c -o sender -lrtp
Alternatively, you can use the make file to compile the RTP programs as follows:
$ make all
or
$ make sender
$ make recver
|