diff --git a/libavformat/internal.h b/libavformat/internal.h
index 789988019d..a395c2f24b 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -137,4 +137,21 @@ int ff_url_join(char *str, int size, const char *proto,
                 const char *authorization, const char *hostname,
                 int port, const char *fmt, ...);
 
+/**
+ * Appends the media-specific SDP fragment for the media stream c
+ * to the buffer buff.
+ *
+ * Note, the buffer needs to be initialized, since it is appended to
+ * existing content.
+ *
+ * @param buff the buffer to append the SDP fragment to
+ * @param size the size of the buff buffer
+ * @param c the AVCodecContext of the media to describe
+ * @param dest_addr the destination address of the media stream, may be NULL
+ * @param port the destination port of the media stream, 0 if unknown
+ * @param ttl the time to live of the stream, 0 if not multicast
+ */
+void ff_sdp_write_media(char *buff, int size, AVCodecContext *c,
+                        const char *dest_addr, int port, int ttl);
+
 #endif /* AVFORMAT_INTERNAL_H */
diff --git a/libavformat/sdp.c b/libavformat/sdp.c
index a8cab6a68f..6bf05dbe39 100644
--- a/libavformat/sdp.c
+++ b/libavformat/sdp.c
@@ -294,7 +294,7 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,
     return buff;
 }
 
-static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
+void ff_sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
 {
     const char *type;
     int payload_type;
@@ -352,7 +352,7 @@ int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
             resolve_destination(dst, sizeof(dst));
         }
         for (j = 0; j < ac[i]->nb_streams; j++) {
-            sdp_write_media(buff, size,
+            ff_sdp_write_media(buff, size,
                                   ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
                                   (port > 0) ? port + j * 2 : 0, ttl);
             if (port <= 0) {
@@ -369,4 +369,9 @@ int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 {
     return AVERROR(ENOSYS);
 }
+
+void ff_sdp_write_media(char *buff, int size, AVCodecContext *c,
+                        const char *dest_addr, int port, int ttl)
+{
+}
 #endif