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#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
/* MPEG-2 TS RTP stack */
#define DEBUG 1
#include "rtp.h"
/* Payload types (from RFC 1890):
PT encoding audio/video clock rate channels
name (A/V) (Hz) (audio)
_______________________________________________________________
0 PCMU A 8000 1
1 1016 A 8000 1
2 G721 A 8000 1
3 GSM A 8000 1
4 unassigned A 8000 1
5 DVI4 A 8000 1
6 DVI4 A 16000 1
7 LPC A 8000 1
8 PCMA A 8000 1
9 G722 A 8000 1
10 L16 A 44100 2
11 L16 A 44100 1
12 unassigned A
13 unassigned A
14 MPA A 90000 (see text)
15 G728 A 8000 1
16--23 unassigned A
24 unassigned V
25 CelB V 90000
26 JPEG V 90000
27 unassigned V
28 nv V 90000
29 unassigned V
30 unassigned V
31 H261 V 90000
32 MPV V 90000
33 MP2T AV 90000
34--71 unassigned ?
72--76 reserved N/A N/A N/A
77--95 unassigned ?
96--127 dynamic ?
*/
void initrtp(struct rtpheader *foo,int pt, int type) { /* fill in the MPEG-2 TS deefaults */
/* Note: MPEG-2 TS defines a timestamping base frequency of 90000 Hz. */
foo->b.v=2;
foo->b.p=0;
foo->b.x=0;
foo->b.cc=0;
foo->b.m=0;
foo->b.pt=pt;
foo->b.sequence=rand() & 65535;
foo->timestamp=rand();
foo->ssrc=rand();
foo->type = type;
}
/* Send a single RTP packet, converting the RTP header to network byte order. */
int sendrtp(int fd, struct sockaddr_in *sSockAddr, struct rtpheader *foo, char *data, int len) {
char *buf=(char*)alloca(len+sizeof(struct rtpheader));
int *cast=(int *)foo;
int *outcast=(int *)buf;
outcast[0]=htonl(cast[0]);
outcast[1]=htonl(cast[1]);
memmove(outcast+2,data,len);
fprintf(stderr,"v=%x %x\n",foo->b.v,buf[0]);
return sendto(fd,buf,len+3,0,(struct sockaddr *)sSockAddr,sizeof(*sSockAddr));
}
int getrtp2(int fd, struct rtpheader *rh, char** data, int* lengthData) {
static char buf[1600];
unsigned int intP;
char* charP = (char*) &intP;
int headerSize;
int lengthPacket;
lengthPacket=recv(fd,buf,1590,0);
if (lengthPacket==0)
exit(1);
if (lengthPacket<0) {
fprintf(stderr,"socket read error\n");
exit(2);
}
if (lengthPacket<12) {
fprintf(stderr,"packet too small (%d) to be an rtp frame (>12bytes)\n",lengthPacket);
exit(3);
}
rh->b.v = (unsigned int) ((buf[0]>>6)&0x03);
rh->b.p = (unsigned int) ((buf[0]>>5)&0x01);
rh->b.x = (unsigned int) ((buf[0]>>4)&0x01);
rh->b.cc = (unsigned int) ((buf[0]>>0)&0x0f);
rh->b.m = (unsigned int) ((buf[1]>>7)&0x01);
rh->b.pt = (unsigned int) ((buf[1]>>0)&0x7f);
intP = 0;
memcpy(charP+2,&buf[2],2);
rh->b.sequence = ntohl(intP);
intP = 0;
memcpy(charP,&buf[4],4);
rh->timestamp = ntohl(intP);
headerSize = 12 + 4*rh->b.cc; /* in bytes */
*lengthData = lengthPacket - headerSize;
*data = (char*) buf + headerSize;
// fprintf(stderr,"Reading rtp: v=%x p=%x x=%x cc=%x m=%x pt=%x seq=%x ts=%x lgth=%d\n",rh->b.v,rh->b.p,rh->b.x,rh->b.cc,rh->b.m,rh->b.pt,rh->b.sequence,rh->timestamp,lengthPacket);
return(0);
}
/* Send a single RTP packet, converting the RTP header to network byte order. */
int sendrtp2(int fd, struct sockaddr_in *sSockAddr, struct rtpheader *foo, char *data, int len) {
char *buf;
unsigned int intP;
char* charP = (char*) &intP;
int headerSize;
if(foo->type == RTP) {
buf=(char*)alloca(len+72);
buf[0] = 0x00;
buf[0] |= ((((char) foo->b.v)<<6)&0xc0);
buf[0] |= ((((char) foo->b.p)<<5)&0x20);
buf[0] |= ((((char) foo->b.x)<<4)&0x10);
buf[0] |= ((((char) foo->b.cc)<<0)&0x0f);
buf[1] = 0x00;
buf[1] |= ((((char) foo->b.m)<<7)&0x80);
buf[1] |= ((((char) foo->b.pt)<<0)&0x7f);
intP = htonl(foo->b.sequence);
memcpy(&buf[2],charP+2,2);
intP = htonl(foo->timestamp);
memcpy(&buf[4],&intP,4);
/* SSRC: not implemented */
buf[8] = 0x0f;
buf[9] = 0x0f;
buf[10] = 0x0f;
buf[11] = 0x0f;
headerSize = 12 + 4*foo->b.cc; /* in bytes */
memcpy(buf+headerSize,data,len);
// fprintf(stderr,"Sending rtp: v=%x p=%x x=%x cc=%x m=%x pt=%x seq=%x ts=%x lgth=%d\n",foo->b.v,foo->b.p,foo->b.x,foo->b.cc,foo->b.m,foo->b.pt,foo->b.sequence,foo->timestamp,len+headerSize);
foo->b.sequence++;
} else { //UDP
buf = data;
headerSize = 0;
}
return sendto(fd,buf,len+headerSize,0,(struct sockaddr *)sSockAddr,sizeof(*sSockAddr));
}
int getrtp(int fd, struct rtpheader *rh, char** data, int* lengthData) {
static char buf[1600];
int headerSize;
int lengthPacket;
lengthPacket=recv(fd,buf,1590,0);
headerSize = 3;
*lengthData = lengthPacket - headerSize;
*data = (char*) buf + headerSize;
fprintf(stderr,"[%d] %02x %x\n",lengthPacket,buf[8],buf[0]);
return(0);
}
/* create a sender socket. */
int makesocket(char *szAddr,unsigned short port,int TTL,struct sockaddr_in *sSockAddr) {
int iRet, iLoop = 1;
struct sockaddr_in sin;
char cTtl = (char)TTL;
char cLoop=0;
int iSocket = socket( AF_INET, SOCK_DGRAM, 0 );
if (iSocket < 0) {
fprintf(stderr,"socket() failed.\n");
exit(1);
}
sSockAddr->sin_family = sin.sin_family = AF_INET;
sSockAddr->sin_port = sin.sin_port = htons(port);
sSockAddr->sin_addr.s_addr = inet_addr(szAddr);
iRet = setsockopt(iSocket, SOL_SOCKET, SO_REUSEADDR, &iLoop, sizeof(int));
if (iRet < 0) {
fprintf(stderr,"setsockopt SO_REUSEADDR failed\n");
exit(1);
}
iRet = setsockopt(iSocket, IPPROTO_IP, IP_MULTICAST_TTL, &cTtl, sizeof(char));
if (iRet < 0) {
fprintf(stderr,"setsockopt IP_MULTICAST_TTL failed. multicast in kernel?\n");
exit(1);
}
cLoop = 1; /* !? */
iRet = setsockopt(iSocket, IPPROTO_IP, IP_MULTICAST_LOOP,
&cLoop, sizeof(char));
if (iRet < 0) {
fprintf(stderr,"setsockopt IP_MULTICAST_LOOP failed. multicast in kernel?\n");
exit(1);
}
return iSocket;
}
/* create a receiver socket, i.e. join the multicast group. */
int makeclientsocket(char *szAddr,unsigned short port,int TTL,struct sockaddr_in *sSockAddr) {
int socket=makesocket(szAddr,port,TTL,sSockAddr);
struct ip_mreq blub;
struct sockaddr_in sin;
unsigned int tempaddr;
sin.sin_family=AF_INET;
sin.sin_port=htons(port);
sin.sin_addr.s_addr=inet_addr(szAddr);
if (bind(socket,(struct sockaddr *)&sin,sizeof(sin))) {
perror("bind failed");
exit(1);
}
tempaddr=inet_addr(szAddr);
if ((ntohl(tempaddr) >> 28) == 0xe) {
blub.imr_multiaddr.s_addr = inet_addr(szAddr);
blub.imr_interface.s_addr = 0;
if (setsockopt(socket,IPPROTO_IP,IP_ADD_MEMBERSHIP,&blub,sizeof(blub))) {
perror("setsockopt IP_ADD_MEMBERSHIP failed (multicast kernel?)");
exit(1);
}
}
return socket;
}
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