rtpdec: add a trace when jitter buffer is full

This commit adds an error trace when jitter buffer
is full. It helps to understand leading decoding issues.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/rtpdec.c

@@ -815,8 +815,11 @@ static int rtp_parse_one_packet(RTPDemuxContext *s, AVPacket *pkt,
             *bufptr = NULL;
             /* Return the first enqueued packet if the queue is full,
              * even if we're missing something */
-            if (s->queue_len >= s->queue_size)
+            if (s->queue_len >= s->queue_size) {
+                av_log(s->st ? s->st->codec : NULL, AV_LOG_ERROR,
+                        "jitter buffer full\n");
                 return rtp_parse_queued_packet(s, pkt);
+            }
             return -1;
         }
     }