Code Sample: Building an SDP Session Structure

This example uses the functions in this section to create a new SDP session structure, add fields to the structure, and convert a finished structure to its string representation. At the end of the example, the program calls the sdp_free_session() function to free the session.

Example 3–1 Building an SDP Session Structure

/* SDP Message we will be building
"v=0\r\n\
o=Alice 2890844526 2890842807 IN IP4 10.47.16.5\r\n\
s=-\r\n\
i=A Seminar on the session description protocol\r\n\
u=http://www.example.com/seminars/sdp.pdf\r\n\
e=alice@example.com (Alice Smith)\r\n\
p=+1 911-345-1160\r\n\
c=IN IP4 10.47.16.5\r\n\
b=CT:1024\r\n\
t=2854678930 2854679000\r\n\
r=604800 3600 0 90000\r\n\
z=2882844526 -1h 2898848070 0h\r\n\
a=recvonly\r\n\
m=audio 49170 RTP/AVP 0\r\n\
i=audio media\r\n\
b=CT:1000\r\n\
k=prompt\r\n\
m=video 51372 RTP/AVP 99 90\r\n\
i=video media\r\n\
a=rtpmap:99 h232-199/90000\r\n\
a=rtpmap:90 h263-1998/90000\r\n"
*/

#include stdio.h>
#include string.h>
#include errno.h>
#include sdp.h>

int main ()
{
   sdp_session_t  *my_sess;
   sdp_media_t    *my_media;
   sdp_time_t     *my_time;
   char *b_sdp;

   my_sess = sdp_new_session();
   if (my_sess == NULL) {
return (ENOMEM);
   }
   my_sess->version = 0;
   if (sdp_add_name(my_sess, "-") != 0)
goto err_ret;
   if (sdp_add_origin(my_sess, "Alice", 2890844526ULL, 2890842807ULL,
 "IN", "IP4", "10.47.16.5") != 0)
goto err_ret;
   if (sdp_add_information(&my_sess->s_info, "A Seminar on the session"
 "description protocol") != 0)
goto err_ret;
   if (sdp_add_uri (my_sess, "http://www.example.com/seminars/sdp.pdf")
 != 0)
goto err_ret;
   if (sdp_add_email(my_sess, "alice@example.com (Alice smith)") != 0)
goto err_ret;
   if (sdp_add_phone(my_sess, "+1 911-345-1160") != 0)
goto err_ret;
   if (sdp_add_connection(&my_sess->s_conn, "IN", "IP4", "10.47.16.5",
0, 0) != 0)
goto err_ret;
   if (sdp_add_bandwidth(&my_sess->s_bw, "CT", 1024) != 0)
goto err_ret;
   if (sdp_add_time(my_sess, 2854678930ULL, 2854679000ULL, &my_time)
!= 0)
goto err_ret;
   if (sdp_add_repeat(my_time, 604800ULL, 3600ULL, "0 90000") != 0)
goto err_ret;
   if (sdp_add_zone(my_sess, 2882844526ULL, "-1h") != 0)
goto err_ret;
   if (sdp_add_zone(my_sess, 2898848070ULL, "0h") != 0)
goto err_ret;
   if (sdp_add_attribute(&my_sess->s_attr, "sendrecv", NULL) != 0)
goto err_ret;
   if (sdp_add_media(my_sess, "audio", 49170, 1, "RTP/AVP",
"0", &my_media) != 0)
goto err_ret;
   if (sdp_add_information(&my_media->m_info, "audio media") != 0)
goto err_ret;
   if (sdp_add_bandwidth(&my_media->m_bw, "CT", 1000) != 0)
goto err_ret;
   if (sdp_add_key(&my_media->m_key, "prompt", NULL) != 0)
goto err_ret;
   if (sdp_add_media(my_sess, "video", 51732, 1, "RTP/AVP",
 "99 90", &my_media) != 0)
goto err_ret;
   if (sdp_add_information(&my_media->m_info, "video media") != 0)
goto err_ret;
   if (sdp_add_attribute(&my_media->m_attr, "rtpmap",
      "99 h232-199/90000") != 0)
goto err_ret;
   if (sdp_add_attribute(&my_media->m_attr, "rtpmap",
      "90 h263-1998/90000") != 0)
goto err_ret;
   b_sdp = sdp_session_to_str(my_sess, &error);

   /*
    * b_sdp is the string representation of my_sess structure
    */

   free(b_sdp);
   sdp_free_session(my_sess);
   return (0);
err_ret:
   free(b_sdp);
   sdp_free_session(my_sess);
   return (1);
}