rtp: Replace hardcoded RTCP packet types with defines

Patch by Josh Allmann, joshua dot allmann at gmail

Originally committed as revision 24912 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/rtp.h

@@ -82,4 +82,13 @@ enum CodecID ff_rtp_codec_id(const char *buf, enum AVMediaType codec_type);
  */
 #define RTP_XIPH_IDENT 0xfecdba
 
+/* RTCP packet types */
+enum RTCPType {
+    RTCP_SR     = 200,
+    RTCP_RR,   // 201
+    RTCP_SDES, // 202
+    RTCP_BYE,  // 203
+    RTCP_APP   // 204
+};
+
 #endif /* AVFORMAT_RTP_H */