libmpdemux/rtp.c

   1 /* Imported from the dvbstream-0.2 project */
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <unistd.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <sys/types.h>
   8 #include "config.h"
   9 #ifndef HAVE_WINSOCK2
  10 #include <netinet/in.h>
  11 #include <sys/socket.h>
  12 #include <arpa/inet.h>
  13 #else
  14 #include <winsock2.h>
  15 #include <ws2tcpip.h>
  16 #endif
  17
  18 /* MPEG-2 TS RTP stack */
  19
  20 #define DEBUG        1
  21 #include "rtp.h"
  22
  23 void initrtp(struct rtpheader *foo) { /* fill in the MPEG-2 TS deefaults */
  24   /* Note: MPEG-2 TS defines a timestamping base frequency of 90000 Hz. */
  25   foo->b.v=2;
  26   foo->b.p=0;
  27   foo->b.x=0;
  28   foo->b.cc=0;
  29   foo->b.m=0;
  30   foo->b.pt=33;                     /* MPEG-2 TS */
  31   foo->b.sequence=rand() & 65535;
  32   foo->timestamp=rand();
  33   foo->ssrc=rand();
  34 }
  35
  36 /* Send a single RTP packet, converting the RTP header to network byte order. */
  37 int sendrtp(int fd, struct sockaddr_in *sSockAddr, struct rtpheader *foo, char *data, int len) {
  38   char *buf=(char*)alloca(len+sizeof(struct rtpheader));
  39   int *cast=(int *)foo;
  40   int *outcast=(int *)buf;
  41   outcast[0]=htonl(cast[0]);
  42   outcast[1]=htonl(cast[1]);
  43   memmove(outcast+2,data,len);
  44   fprintf(stderr,"v=%x %x\n",foo->b.v,buf[0]);
  45   return sendto(fd,buf,len+3,0,(struct sockaddr *)sSockAddr,sizeof(*sSockAddr));
  46 }
  47
  48 int getrtp2(int fd, struct rtpheader *rh, char** data, int* lengthData) {
  49   static char buf[1600];
  50   unsigned int intP;
  51   char* charP = (char*) &intP;
  52   int headerSize;
  53   int lengthPacket;
  54   lengthPacket=recv(fd,buf,1590,0);
  55   if (lengthPacket==0)
  56     exit(1);
  57   if (lengthPacket<0) {
  58     fprintf(stderr,"socket read error\n");
  59     exit(2);
  60   }
  61   if (lengthPacket<12) {
  62     fprintf(stderr,"packet too small (%d) to be an rtp frame (>12bytes)\n", lengthPacket);
  63     exit(3);
  64   }
  65   rh->b.v  = (unsigned int) ((buf[0]>>6)&0x03);
  66   rh->b.p  = (unsigned int) ((buf[0]>>5)&0x01);
  67   rh->b.x  = (unsigned int) ((buf[0]>>4)&0x01);
  68   rh->b.cc = (unsigned int) ((buf[0]>>0)&0x0f);
  69   rh->b.m  = (unsigned int) ((buf[1]>>7)&0x01);
  70   rh->b.pt = (unsigned int) ((buf[1]>>0)&0x7f);
  71   intP = 0;
  72   memcpy(charP+2,&buf[2],2);
  73   rh->b.sequence = ntohl(intP);
  74   intP = 0;
  75   memcpy(charP,&buf[4],4);
  76   rh->timestamp = ntohl(intP);
  77
  78   headerSize = 12 + 4*rh->b.cc; /* in bytes */
  79
  80   *lengthData = lengthPacket - headerSize;
  81   *data = (char*) buf + headerSize;
  82
  83   //  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);
  84
  85   return(0);
  86 }
  87
  88 /* Send a single RTP packet, converting the RTP header to network byte order. */
  89 int sendrtp2(int fd, struct sockaddr_in *sSockAddr, struct rtpheader *foo, char *data, int len) {
  90   char *buf=(char*)alloca(len+72);
  91   unsigned int intP;
  92   char* charP = (char*) &intP;
  93   int headerSize;
  94   buf[0]  = 0x00;
  95   buf[0] |= ((((char) foo->b.v)<<6)&0xc0);
  96   buf[0] |= ((((char) foo->b.p)<<5)&0x20);
  97   buf[0] |= ((((char) foo->b.x)<<4)&0x10);
  98   buf[0] |= ((((char) foo->b.cc)<<0)&0x0f);
  99   buf[1]  = 0x00;
 100   buf[1] |= ((((char) foo->b.m)<<7)&0x80);
 101   buf[1] |= ((((char) foo->b.pt)<<0)&0x7f);
 102   intP = htonl(foo->b.sequence);
 103   memcpy(&buf[2],charP+2,2);
 104   intP = htonl(foo->timestamp);
 105   memcpy(&buf[4],&intP,4);
 106   /* SSRC: not implemented */
 107   buf[8]  = 0x0f;
 108   buf[9]  = 0x0f;
 109   buf[10] = 0x0f;
 110   buf[11] = 0x0f;
 111   headerSize = 12 + 4*foo->b.cc; /* in bytes */
 112   memcpy(buf+headerSize,data,len);
 113
 114   //  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);
 115
 116   foo->b.sequence++;
 117   return sendto(fd,buf,len+headerSize,0,(struct sockaddr *)sSockAddr,sizeof(*sSockAddr));
 118 }
 119
 120
 121 int getrtp(int fd, struct rtpheader *rh, char** data, int* lengthData) {
 122   static char buf[1600];
 123   int headerSize;
 124   int lengthPacket;
 125
 126   lengthPacket=recv(fd,buf,1590,0);
 127   // FIXME: error handling to write here
 128   headerSize = 3;
 129   *lengthData = lengthPacket - headerSize;
 130   *data = (char*) buf + headerSize;
 131   fprintf(stderr,"[%d] %02x %x\n",lengthPacket,buf[8],buf[0]);
 132   return(0);
 133 }
 134
 135 /* create a sender socket. */
 136 int makesocket(char *szAddr,unsigned short port,int TTL,struct sockaddr_in *sSockAddr) {
 137   int          iRet, iLoop = 1;
 138   struct       sockaddr_in sin;
 139   char         cTtl = (char)TTL;
 140   char         cLoop=0;
 141
 142   int iSocket = socket( AF_INET, SOCK_DGRAM, 0 );
 143
 144   if (iSocket < 0) {
 145     fprintf(stderr,"socket() failed.\n");
 146     exit(1);
 147   }
 148
 149   sSockAddr->sin_family = sin.sin_family = AF_INET;
 150   sSockAddr->sin_port = sin.sin_port = htons(port);
 151   sSockAddr->sin_addr.s_addr = inet_addr(szAddr);
 152
 153   iRet = setsockopt(iSocket, SOL_SOCKET, SO_REUSEADDR, &iLoop, sizeof(int));
 154   if (iRet < 0) {
 155     fprintf(stderr,"setsockopt SO_REUSEADDR failed\n");
 156     exit(1);
 157   }
 158
 159   iRet = setsockopt(iSocket, IPPROTO_IP, IP_MULTICAST_TTL, &cTtl, sizeof(char));
 160   if (iRet < 0) {
 161     fprintf(stderr,"setsockopt IP_MULTICAST_TTL failed.  multicast in kernel?\n");
 162     exit(1);
 163   }
 164
 165   cLoop = 1;    /* !? */
 166   iRet = setsockopt(iSocket, IPPROTO_IP, IP_MULTICAST_LOOP,
 167                     &cLoop, sizeof(char));
 168   if (iRet < 0) {
 169     fprintf(stderr,"setsockopt IP_MULTICAST_LOOP failed.  multicast in kernel?\n");
 170     exit(1);
 171   }
 172
 173   return iSocket;
 174 }
 175
 176 /* create a receiver socket, i.e. join the multicast group. */
 177 int makeclientsocket(char *szAddr,unsigned short port,int TTL,struct sockaddr_in *sSockAddr) {
 178   int socket=makesocket(szAddr,port,TTL,sSockAddr);
 179   struct ip_mreq blub;
 180   struct sockaddr_in sin;
 181   unsigned int tempaddr;
 182   sin.sin_family=AF_INET;
 183   sin.sin_port=htons(port);
 184   sin.sin_addr.s_addr=inet_addr(szAddr);
 185   if (bind(socket,(struct sockaddr *) &sin,sizeof(sin))) {
 186     perror("bind failed");
 187     exit(1);
 188   }
 189   tempaddr=inet_addr(szAddr);
 190   if ((ntohl(tempaddr) >> 28) == 0xe) {
 191     blub.imr_multiaddr.s_addr = inet_addr(szAddr);
 192     blub.imr_interface.s_addr = 0;
 193     if (setsockopt(socket,IPPROTO_IP,IP_ADD_MEMBERSHIP,&blub,sizeof(blub))) {
 194       perror("setsockopt IP_ADD_MEMBERSHIP failed (multicast kernel?)");
 195       exit(1);
 196     }
 197   }
 198   return socket;
 199 }
 200