+
+static char *
+vsdp_AddAttribute (char **sdp, const char *name, const char *fmt, va_list ap)
+{
+ size_t oldlen = strlen (*sdp);
+ size_t addlen = sizeof ("a=\r\n") + strlen (name);
+
+ if (fmt != NULL)
+ {
+ va_list aq;
+
+ va_copy (aq, ap);
+ addlen += 1 + vsnprintf (NULL, 0, fmt, aq);
+ va_end (aq);
+ }
+
+ char *ret = realloc (*sdp, oldlen + addlen);
+ if (ret == NULL)
+ return NULL;
+
+ oldlen += sprintf (ret + oldlen, "a=%s", name);
+ if (fmt != NULL)
+ {
+ ret[oldlen++] = ':';
+ oldlen += vsprintf (ret + oldlen, fmt, ap);
+ }
+
+ strcpy (ret + oldlen, "\r\n");
+ return *sdp = ret;
+}
+
+
+char *sdp_AddAttribute (char **sdp, const char *name, const char *fmt, ...)
+{
+ char *ret;
+ va_list ap;
+
+ va_start (ap, fmt);
+ ret = vsdp_AddAttribute (sdp, name, fmt, ap);
+ va_end (ap);
+
+ return ret;
+}
+
+
+char *sdp_AddMedia (char **sdp,
+ const char *type, const char *protocol, int dport,
+ unsigned pt, vlc_bool_t bw_indep, unsigned bw,
+ const char *rtpmap, const char *fmtp)
+{
+ char *newsdp, *ptr;
+ size_t inlen = strlen (*sdp), outlen = inlen;
+
+ /* Some default values */
+ if (type == NULL)
+ type = "video";
+ if (protocol == NULL)
+ protocol = "RTP/AVP";
+ assert (pt < 128u);
+
+ outlen += snprintf (NULL, 0,
+ "m=%s %u %s %d\r\n"
+ "b=TIAS:%u\r\n"
+ "b=RR:0\r\n",
+ type, dport, protocol, pt, bw);
+
+ newsdp = realloc (*sdp, outlen + 1);
+ if (newsdp == NULL)
+ return NULL;
+
+ *sdp = newsdp;
+ ptr = newsdp + inlen;
+
+ ptr += sprintf (ptr, "m=%s %u %s %u\r\n",
+ type, dport, protocol, pt);
+ if (bw > 0)
+ ptr += sprintf (ptr, "b=%s:%u\r\n", bw_indep ? "TIAS" : "AS", bw);
+ ptr += sprintf (ptr, "b=RR:0\r\n");
+
+ /* RTP payload type map */
+ if (rtpmap != NULL)
+ sdp_AddAttribute (sdp, "rtpmap", "%u %s", pt, rtpmap);
+ /* Format parameters */
+ if (fmtp != NULL)
+ sdp_AddAttribute (sdp, "fmtp", "%u %s", pt, fmtp);
+
+ return newsdp;
+}
+
+
+char *vlc_sdp_Start (vlc_object_t *obj, const char *cfgpref,
+ const struct sockaddr *src, size_t srclen,
+ const struct sockaddr *addr, size_t addrlen)
+{
+ size_t cfglen = strlen (cfgpref);
+ if (cfglen > 100)
+ return NULL;
+
+ char varname[cfglen + sizeof ("description")], *subvar = varname + cfglen;
+ strcpy (varname, cfgpref);
+
+ session_descriptor_t *p_session = calloc (1, sizeof (*p_session));
+ if (p_session == NULL)
+ return NULL;
+
+ strcpy (subvar, "name");
+ char *name = var_GetNonEmptyString (obj, varname);
+ strcpy (subvar, "description");
+ char *description = var_GetNonEmptyString (obj, varname);
+ strcpy (subvar, "url");
+ char *url = var_GetNonEmptyString (obj, varname);
+ strcpy (subvar, "email");
+ char *email = var_GetNonEmptyString (obj, varname);
+ strcpy (subvar, "phone");
+ char *phone = var_GetNonEmptyString (obj, varname);
+#if 0
+ strcpy (subvar, "group");
+ char *group = var_GetNonEmptyString (obj, varname);
+#endif
+
+ char *sdp = sdp_Start (name, description, url, email, phone,
+ src, srclen, addr, addrlen);
+ free (name);
+ free (description);
+ free (url);
+ free (email);
+ free (phone);
+
+ return sdp;
+}