diff --git a/libavformat/rtsp.c b/libavformat/rtsp.c
index fc422aa488..f1bd870b50 100644
--- a/libavformat/rtsp.c
+++ b/libavformat/rtsp.c
@@ -273,9 +273,7 @@ int ff_rtsp_next_attr_and_value(const char **p, char *attr, int attr_size,
 static void sdp_parse_fmtp(AVStream *st, const char *p)
 {
     char attr[256];
-    /* Vorbis setup headers can be up to 12KB and are sent base64
-     * encoded, giving a 12KB * (4/3) = 16KB FMTP line. */
-    char value[16384];
+    char value[4096];
     int i;
     RTSPStream *rtsp_st = st->priv_data;
     AVCodecContext *codec = st->codec;
@@ -541,7 +539,8 @@ static int sdp_parse(AVFormatContext *s, const char *content)
      * "rulebooks" describing their properties. Therefore, the SDP line
      * buffer is large.
      *
-     * The Vorbis FMTP line can be up to 16KB - see sdp_parse_fmtp. */
+     * The Vorbis FMTP line can be up to 16KB - see xiph_parse_sdp_line
+     * in rtpdec_xiph.c. */
     char buf[16384], *q;
     SDPParseState sdp_parse_state, *s1 = &sdp_parse_state;