diff --git a/trunk/3rdparty/st-srs/io.c b/trunk/3rdparty/st-srs/io.c
index 35a3110c6..7e05f99ae 100644
--- a/trunk/3rdparty/st-srs/io.c
+++ b/trunk/3rdparty/st-srs/io.c
@@ -742,12 +742,9 @@ int st_sendmsg(_st_netfd_t *fd, const struct msghdr *msg, int flags, st_utime_t
     return n;
 }
 
-
-int st_sendmmsg(st_netfd_t fd, void *msgvec, unsigned int vlen, int flags, st_utime_t timeout)
+int st_sendmmsg(st_netfd_t fd, struct st_mmsghdr *msgvec, unsigned int vlen, int flags, st_utime_t timeout)
 {
-#if !defined(MD_HAVE_SENDMMSG) || !defined(_GNU_SOURCE)
-    return -1;
-#else
+#if defined(MD_HAVE_SENDMMSG) && defined(_GNU_SOURCE)
     int n;
     int left;
     struct mmsghdr *p;
@@ -774,6 +771,28 @@ int st_sendmmsg(st_netfd_t fd, void *msgvec, unsigned int vlen, int flags, st_ut
         return n;
     }
     return (int)vlen - left;
+#else
+    struct st_mmsghdr *p;
+    int i, n;
+
+    // @see http://man7.org/linux/man-pages/man2/sendmmsg.2.html
+    for (i = 0; i < (int)vlen; ++i) {
+        p = msgvec + i;
+        n = st_sendmsg(fd, &p->msg_hdr, flags, timeout);
+        if (n < 0) {
+            // An error is returned only if no datagrams could be sent.
+            if (i == 0) {
+                return n;
+            }
+            return i + 1;
+        }
+
+        p->msg_len = n;
+    }
+
+    // Returns the number of messages sent from msgvec; if this is less than vlen, the caller can retry with a
+    // further sendmmsg() call to send the remaining messages.
+    return vlen;
 #endif
 }
 
diff --git a/trunk/3rdparty/st-srs/public.h b/trunk/3rdparty/st-srs/public.h
index a581adc08..80fd93346 100644
--- a/trunk/3rdparty/st-srs/public.h
+++ b/trunk/3rdparty/st-srs/public.h
@@ -151,7 +151,15 @@ extern int st_recvfrom(st_netfd_t fd, void *buf, int len, struct sockaddr *from,
 extern int st_sendto(st_netfd_t fd, const void *msg, int len, const struct sockaddr *to, int tolen, st_utime_t timeout);
 extern int st_recvmsg(st_netfd_t fd, struct msghdr *msg, int flags, st_utime_t timeout);
 extern int st_sendmsg(st_netfd_t fd, const struct msghdr *msg, int flags, st_utime_t timeout);
-extern int st_sendmmsg(st_netfd_t fd, void *msgvec, unsigned int vlen, int flags, st_utime_t timeout);
+
+// @see http://man7.org/linux/man-pages/man2/sendmmsg.2.html
+#include <sys/socket.h>
+struct st_mmsghdr {
+   struct msghdr msg_hdr;  /* Message header */
+   unsigned int  msg_len;  /* Number of bytes transmitted */
+};
+extern int st_sendmmsg(st_netfd_t fd, struct st_mmsghdr *msgvec, unsigned int vlen, int flags, st_utime_t timeout);
+
 extern st_netfd_t st_open(const char *path, int oflags, mode_t mode);
 
 #ifdef DEBUG
diff --git a/trunk/auto/options.sh b/trunk/auto/options.sh
index a5848485b..97f6dcf92 100755
--- a/trunk/auto/options.sh
+++ b/trunk/auto/options.sh
@@ -608,6 +608,11 @@ function apply_user_detail_options() {
         echo "Disable SRTP ASM, because NASM is disabled."
         SRS_SRTP_ASM=NO
     fi
+
+    if [[ $SRS_OSX == YES && $SRS_SENDMMSG == YES ]]; then
+        echo "Disable sendmmsg for OSX"
+        SRS_SENDMMSG=NO
+    fi
 }
 apply_user_detail_options
 
diff --git a/trunk/configure b/trunk/configure
index 974a9163b..115e5f8d5 100755
--- a/trunk/configure
+++ b/trunk/configure
@@ -188,7 +188,7 @@ if [[ $SRS_GCOV == YES ]]; then
     SrsLinkOptions="${SrsLinkOptions} ${SrsGcov}";
 fi
 # For FFMPEG/RTC.
-if [[ $SRS_RTC == YES && $SRS_NASM == NO ]]; then
+if [[ $SRS_RTC == YES && $SRS_NASM == NO && $SRS_OSX == NO ]]; then
     SrsLinkOptions="${SrsLinkOptions} -lrt";
 fi
 
diff --git a/trunk/src/service/srs_service_st.cpp b/trunk/src/service/srs_service_st.cpp
index 78e3705d8..e7181cae4 100644
--- a/trunk/src/service/srs_service_st.cpp
+++ b/trunk/src/service/srs_service_st.cpp
@@ -414,51 +414,7 @@ int srs_sendmsg(srs_netfd_t stfd, const struct msghdr *msg, int flags, srs_utime
 
 int srs_sendmmsg(srs_netfd_t stfd, struct srs_mmsghdr *msgvec, unsigned int vlen, int flags, srs_utime_t timeout)
 {
-#if !defined(SRS_SENDMMSG)
-    // @see http://man7.org/linux/man-pages/man2/sendmmsg.2.html
-    for (int i = 0; i < (int)vlen; ++i) {
-        struct srs_mmsghdr* p = msgvec + i;
-        int n = srs_sendmsg(stfd, &p->msg_hdr, flags, timeout);
-        if (n < 0) {
-            // An error is returned only if no datagrams could be sent.
-            if (i == 0) {
-                return n;
-            }
-            return i + 1;
-        }
-
-        p->msg_len = n;
-    }
-    // Returns the number of messages sent from msgvec; if this is less than vlen, the caller can retry with a
-    // further sendmmsg() call to send the remaining messages.
-    return vlen;
-#else
-    if (vlen == 1) {
-        #if 1
-            int r0 = srs_sendmsg(stfd, &msgvec->msg_hdr, flags, timeout);
-            if (r0 < 0) {
-                return r0;
-            }
-            msgvec->msg_len = r0;
-        #else
-            msgvec->msg_len = 0;
-
-            int tolen = (int)msgvec->msg_hdr.msg_namelen;
-            const struct sockaddr* to = (const struct sockaddr*)msgvec->msg_hdr.msg_name;
-            for (int i = 0; i < (int)msgvec->msg_hdr.msg_iovlen; i++) {
-                iovec* iov = msgvec->msg_hdr.msg_iov + i;
-                int r0 = srs_sendto(stfd, (void*)iov->iov_base, (int)iov->iov_len, to, tolen, timeout);
-                if (r0 < 0) {
-                    return r0;
-                }
-                msgvec->msg_len += r0;
-            }
-        #endif
-
-        return 1;
-    }
-    return st_sendmmsg((st_netfd_t)stfd, (void*)msgvec, vlen, flags, (st_utime_t)timeout);
-#endif
+    return st_sendmmsg((st_netfd_t)stfd, (struct st_mmsghdr*)msgvec, vlen, flags, (st_utime_t)timeout);
 }
 
 srs_netfd_t srs_accept(srs_netfd_t stfd, struct sockaddr *addr, int *addrlen, srs_utime_t timeout)